Merge remote-tracking branch 'Baeldung/master' into active_mq

# Conflicts: # .gitignore # LICENSE # README.md # core-java-modules/README.md # core-java-modules/core-java-11/README.md # core-java-modules/core-java-11/pom.xml # core-java-modules/core-java-8/README.md # core-java-modules/core-java-8/pom.xml # core-java-modules/core-java-8/src/main/resources/logback.xml # core-java-modules/core-java-annotations/README.md # core-java-modules/core-java-annotations/pom.xml # core-java-modules/core-java-collections-2/README.md # core-java-modules/core-java-collections-2/pom.xml # core-java-modules/core-java-collections-3/README.md # core-java-modules/core-java-collections-3/pom.xml # core-java-modules/core-java-collections-conversions-2/README.md # core-java-modules/core-java-collections-conversions-2/pom.xml # core-java-modules/core-java-collections-conversions/README.md # core-java-modules/core-java-collections-conversions/pom.xml # core-java-modules/core-java-collections-list/README.md # core-java-modules/core-java-collections-list/pom.xml # core-java-modules/core-java-collections/pom.xml # core-java-modules/core-java-datetime-conversion/README.md # core-java-modules/core-java-datetime-conversion/pom.xml # core-java-modules/core-java-datetime-conversion/src/test/java/com/baeldung/datetime/ConvertInstantToTimestampUnitTest.java # core-java-modules/core-java-io-2/pom.xml # core-java-modules/core-java-io/README.md # core-java-modules/core-java-io/pom.xml # core-java-modules/core-java-io/src/test/resources/fileTest.txt # core-java-modules/core-java-io/src/test/resources/sampleTextFile.txt # core-java-modules/core-java-lambdas/README.md # core-java-modules/core-java-lambdas/pom.xml # core-java-modules/core-java-serialization/pom.xml # core-java-modules/core-java-streams/README.md # core-java-modules/core-java-streams/pom.xml # core-java-modules/core-java-strings/README.md # core-java-modules/core-java-strings/pom.xml # core-java-modules/core-java-strings/src/test/resources/stringtoolong.txt # core-java-modules/core-java-uuid/README.md # core-java-modules/core-java-uuid/pom.xml # core-java-modules/pom.xml # image-processing/README.md # image-processing/pom.xml # image-processing/src/main/java/com/baeldung/imageprocessing/addingtext/AddText.java # image-processing/src/main/java/com/baeldung/imageprocessing/opencv/CameraStream.java # jackson-modules/jackson-annotations/README.md # jackson-modules/jackson-annotations/pom.xml # jackson-modules/jackson-conversions-2/README.md # jackson-modules/jackson-conversions-2/pom.xml # jackson-modules/jackson-conversions/README.md # jackson-modules/jackson-conversions/pom.xml # jackson-modules/jackson-custom-conversions/README.md # jackson-modules/jackson-custom-conversions/pom.xml # jackson-modules/jackson-custom-conversions/src/test/java/com/baeldung/defaultserializercustomserializer/CallingDefaultSerializerUnitTest.java # jackson-modules/jackson-custom-conversions/src/test/java/com/baeldung/deserialization/CustomDeserializationUnitTest.java # jackson-modules/jackson-exceptions/README.md # jackson-modules/jackson-exceptions/pom.xml # jackson-modules/jackson-exceptions/src/test/java/com/baeldung/exceptions/JacksonExceptionsUnitTest.java # jackson-modules/jackson-exceptions/src/test/java/com/baeldung/mappingexception/JacksonMappingExceptionUnitTest.java # jackson-modules/pom.xml # parent-boot-1/pom.xml # parent-boot-2/pom.xml # parent-boot-3/pom.xml # patterns-modules/design-patterns-architectural/pom.xml # patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/UserDaoImpl.java # patterns-modules/design-patterns-behavioral-2/README.md # patterns-modules/design-patterns-behavioral-2/pom.xml # patterns-modules/design-patterns-creational-2/README.md # patterns-modules/design-patterns-creational-2/pom.xml # patterns-modules/design-patterns-singleton/README.md # patterns-modules/design-patterns-structural/src/main/resources/log4jstructuraldp.properties # patterns-modules/enterprise-patterns/pom.xml # patterns-modules/intercepting-filter/pom.xml # patterns-modules/pom.xml # persistence-modules/activejdbc/pom.xml # persistence-modules/hibernate5/README.md # persistence-modules/hibernate5/pom.xml # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/interceptors/CustomInterceptor.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/interceptors/entity/User.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/namingstrategy/CustomPhysicalNamingStrategy.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/persistjson/Customer.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/persistjson/HashMapConverter.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/pojo/OrderEntryIdClass.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/pojo/OrderEntryPK.java # persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/IdentifiersIntegrationTest.java # persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/bootstrap/BootstrapAPIIntegrationTest.java # persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/proxy/HibernateProxyUnitTest.java # persistence-modules/hibernate5/src/test/resources/hibernate-interceptors.properties # persistence-modules/hibernate5/src/test/resources/hibernate-lifecycle.properties # persistence-modules/hibernate5/src/test/resources/hibernate-namingstrategy.properties # persistence-modules/hibernate5/src/test/resources/hibernate-persistjson.properties # persistence-modules/hibernate5/src/test/resources/hibernate.properties # persistence-modules/pom.xml # persistence-modules/spring-data-jpa-crud/pom.xml # persistence-modules/spring-data-jpa-crud/src/main/java/com/baeldung/repository/FruitRepository.java # persistence-modules/spring-data-jpa-repo-2/README.md # persistence-modules/spring-data-jpa-repo-2/pom.xml # persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/customrepository/model/User.java # persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/customrepository/repository/CustomUserRepositoryImpl.java # persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/saveperformance/Book.java # persistence-modules/spring-data-jpa-repo-2/src/main/resources/application.properties # persistence-modules/spring-data-mongodb-reactive/pom.xml # persistence-modules/spring-data-redis/README.md # persistence-modules/spring-data-redis/pom.xml # persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/reactive/redis/config/RedisConfig.java # persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/config/RedisConfig.java # persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/model/Student.java # persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/queue/RedisMessageSubscriber.java # persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/reactive/redis/template/RedisKeyCommandsManualTest.java # persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/reactive/redis/template/RedisTemplateListOpsManualTest.java # persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/reactive/redis/template/RedisTemplateValueOpsManualTest.java # persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/redis/repo/StudentRepositoryManualTest.java # pom.xml # testing-modules/assertion-libraries/README.md # testing-modules/assertion-libraries/pom.xml # testing-modules/junit-5-basics/README.md # testing-modules/junit-5-basics/pom.xml # testing-modules/mockito-2/src/main/java/com/baeldung/nullmatcher/Helper.java # testing-modules/mockito-2/src/main/java/com/baeldung/nullmatcher/Main.java # testing-modules/mockito-2/src/main/java/com/baeldung/wantedbutnotinvocked/Helper.java # testing-modules/mockito-2/src/main/java/com/baeldung/wantedbutnotinvocked/Main.java # testing-modules/mockito-2/src/test/java/com/baeldung/nullmatcher/MainUnitTest.java # testing-modules/mockito-2/src/test/java/com/baeldung/wantedbutnotinvocked/MainUnitTest.java # testing-modules/pom.xml # testing-modules/spring-mockito/pom.xml # web-modules/dropwizard/pom.xml # web-modules/jakarta-ee/README.md # web-modules/jakarta-ee/pom.xml # web-modules/jakarta-ee/src/test/java/com/baeldung/eclipse/krazo/UserControllerUnitTest.java # web-modules/java-lite/pom.xml # web-modules/javax-servlets-2/README.md # web-modules/javax-servlets-2/pom.xml # web-modules/javax-servlets/pom.xml # web-modules/jee-7/pom.xml # web-modules/jooby/pom.xml # web-modules/ninja/pom.xml # web-modules/pom.xml # web-modules/ratpack/pom.xml # web-modules/resteasy/pom.xml # web-modules/restx/pom.xml # web-modules/spark-java/pom.xml # web-modules/vraptor/pom.xml # xml/README.md # xml/pom.xml # xml/src/main/resources/customer-binding.xml # xml/src/main/resources/sax/baeldung.xml # xml/src/test/resources/example_default_parser.xml # xml/src/test/resources/example_dom4j.xml # xml/src/test/resources/example_jaxb.xml # xml/src/test/resources/example_jaxen.xml # xml/src/test/resources/example_jdom.xml # xml/src/test/resources/example_stax.xml # xml/src/test/resources/sax/baeldung.xml # xml/src/test/resources/xml/websites.xml # xml/src/test/resources/xml/xee_attribute.xml
2024-04-30 12:23:19 -04:00
parent c18eb6d2ed 8cabe509a5
commit a51b7b55d9
27985 changed files with 1594773 additions and 0 deletions
@@ -0,0 +1,61 @@
+package com.baeldung;
+
+
+import com.baeldung.model.Employee;
+import com.baeldung.model.Role;
+import org.javalite.activejdbc.Base;
+import org.javalite.activejdbc.DB;
+import org.javalite.activejdbc.LazyList;
+import org.javalite.activejdbc.Model;
+
+public class ActiveJDBCApp
+{
+    public static void main( String[] args )
+    {
+        try(final DB open = Base.open()) {
+            ActiveJDBCApp app = new ActiveJDBCApp();
+            app.create();
+            app.update();
+            app.delete();
+            app.deleteCascade();
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            Base.close();
+        }
+    }
+
+    protected void create() {
+        Employee employee = new Employee("Hugo","C","M","BN");
+        employee.saveIt();
+        employee.add(new Role("Java Developer","BN"));
+        LazyList<Model> all = Employee.findAll();
+        System.out.println(all.size());
+    }
+
+    protected void update() {
+        Employee employee = Employee.findFirst("first_name = ?","Hugo");
+        employee.set("last_namea","Choi").saveIt();
+        employee = Employee.findFirst("last_name = ?","Choi");
+        System.out.println(employee.getString("first_name") + " " + employee.getString("last_name"));
+    }
+
+    protected void delete() {
+        Employee employee = Employee.findFirst("first_name = ?","Hugo");
+        employee.delete();
+        employee = Employee.findFirst("last_name = ?","Choi");
+        if(null == employee){
+            System.out.println("No such Employee found!");
+        }
+    }
+
+    protected void deleteCascade() {
+        create();
+        Employee employee = Employee.findFirst("first_name = ?","Hugo");
+        employee.deleteCascade();
+        employee = Employee.findFirst("last_name = ?","C");
+        if(null == employee){
+            System.out.println("No such Employee found!");
+        }
+    }
+}
@@ -0,0 +1,23 @@
+package com.baeldung.model;
+
+
+import org.javalite.activejdbc.Model;
+
+public class Employee extends Model {
+
+    public Employee(){
+
+    }
+
+    public Employee(String firstName, String lastName, String gender, String createdBy) {
+        set("first_name1",firstName);
+        set("last_name",lastName);
+        set("gender",gender);
+        set("created_by",createdBy);
+    }
+
+    public String getLastName() {
+        return getString("last_name");
+    }
+
+}
@@ -0,0 +1,22 @@
+package com.baeldung.model;
+
+
+import org.javalite.activejdbc.Model;
+import org.javalite.activejdbc.annotations.Table;
+
+@Table("EMP_ROLES")
+public class Role extends Model {
+
+    public Role(){
+
+    }
+
+    public Role(String role,String createdBy){
+        set("role_name",role);
+        set("created_by",createdBy);
+    }
+
+    public String getRoleName() {
+        return getString("role_name");
+    }
+}
@@ -0,0 +1,25 @@
+# noinspection SqlNoDataSourceInspectionForFile
+
+create table organisation.employees
+(
+	id int not null auto_increment
+		primary key,
+	first_name varchar(100) not null,
+	last_name varchar(100) not null,
+	gender varchar(1) not null,
+	created_at datetime not null,
+	updated_at datetime null,
+	created_by varchar(100) not null,
+	updated_by varchar(100) null
+)ENGINE = InnoDB DEFAULT CHARSET = utf8;
+
+create table organisation.emp_roles
+(
+	id int not null auto_increment primary key,
+	employee_id int not null,
+	role_name varchar(100) not null,
+	created_at datetime not null,
+	updated_at datetime null,
+	created_by varchar(100) not null,
+	updated_by varchar(100) null
+)ENGINE = InnoDB DEFAULT CHARSET = utf8;
@@ -0,0 +1,10 @@
+development.driver=com.mysql.jdbc.Driver
+development.username=root
+development.password=123456
+development.url=jdbc:mysql://localhost/organisation
+
+
+development.test.driver=com.mysql.jdbc.Driver
+development.test.username=root
+development.test.password=123456
+development.test.url=jdbc:mysql://localhost/organisation_test
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
@@ -0,0 +1,51 @@
+package com.baeldung;
+
+import com.baeldung.model.Employee;
+import com.baeldung.model.Role;
+import org.javalite.activejdbc.test.DBSpec;
+import org.junit.Test;
+
+import java.util.List;
+
+public class ActiveJDBCAppManualTest extends DBSpec
+{
+    @Test
+    public void ifEmployeeCreated_thenIsValid() {
+        Employee employee = new Employee("B", "N", "M", "BN");
+        the(employee).shouldBe("valid");
+    }
+
+    @Test
+    public void ifEmployeeCreatedWithRoles_thenShouldPersist() {
+        Employee employee = new Employee("B", "N", "M", "BN");
+        employee.saveIt();
+        employee.add(new Role("Java Developer","BN"));
+        employee.add(new Role("Lead Java Developer","BN"));
+        a(Role.count()).shouldBeEqual(2);
+        List<Role> roles = employee.getAll(Role.class).orderBy("created_at");
+        the(roles.get(0).getRoleName()).shouldBeEqual("Java Developer");
+        the(roles.get(1).getRoleName()).shouldBeEqual("Lead Java Developer");
+    }
+
+    @Test
+    public void ifEmployeeCreatedWithRoles_whenNameUpdated_thenShouldShowNewName() {
+        Employee employee = new Employee("Binesh", "N", "M", "BN");
+        employee.saveIt();
+        employee.add(new Role("Java Developer","BN"));
+        employee.add(new Role("Lead Java Developer","BN"));
+        employee = Employee.findFirst("first_name = ?", "Binesh");
+        employee.set("last_name","Narayanan").saveIt();
+        Employee updated = Employee.findFirst("first_name = ?", "Binesh");
+        the(updated.getLastName()).shouldBeEqual("Narayanan");
+    }
+
+    @Test
+    public void ifEmployeeCreatedWithRoles_whenDeleted_thenShouldNotBeFound() {
+        Employee employee = new Employee("Binesh", "N", "M", "BN");
+        employee.saveIt();
+        employee.add(new Role("Java Developer","BN"));
+        employee.delete();
+        employee = Employee.findFirst("first_name = ?", "Binesh");
+        the(employee).shouldBeNull();
+    }
+}
@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Guide to Apache BookKeeper](https://www.baeldung.com/java-apache-bookkeeper)
@@ -0,0 +1,5 @@
+bk/bookkeeper/*
+bk1/bookkeeper/*
+bk2/bookkeeper/*
+zk/*
+
@@ -0,0 +1 @@
+/bookkeeper/
@@ -0,0 +1 @@
+/bookkeeper/
@@ -0,0 +1,71 @@
+version: '3.0'
+services:
+  zk:
+    image: zookeeper:3.6.1
+    restart: always
+    ports:
+     - "2181:2181"
+    volumes:
+     - ./data/zk:/data
+
+  bookie_init:
+    image: apache/bookkeeper:4.10.0
+    environment:
+      BK_zkServers: "zk:2181"
+      BK_advertisedAddress: ${BK_PUBLIC_IP}
+    restart: on-failure
+    depends_on:
+      - zk
+    command: /opt/bookkeeper/bin/bookkeeper shell metaformat -nonInteractive
+        
+  bookie:
+    image: apache/bookkeeper:4.10.0
+    restart: on-failure
+    environment:
+      BK_zkServers: "zk:2181"
+      BK_advertisedAddress: ${BK_PUBLIC_IP}
+      BK_httpServerPort: 3182      
+    ports:
+      - "3181:3181"
+      - "3182:3182"
+    volumes:
+      - ./data/bk:/data
+    depends_on:
+      - zk
+      - bookie_init
+
+  bookie1:
+    image: apache/bookkeeper:4.10.0
+    restart: on-failure
+    environment:
+      BOOKIE_PORT: 4181
+      BK_zkServers: "zk:2181"
+      BK_advertisedAddress: ${BK_PUBLIC_IP}
+      BK_httpServerPort: 3182      
+    ports:
+      - "4181:4181"
+    volumes:
+      - ./data/bk1:/data
+    depends_on:
+      - zk
+      - bookie_init
+
+  bookie2:
+    image: apache/bookkeeper:4.10.0
+    restart: on-failure
+    environment:
+      BOOKIE_PORT: 4182
+      BK_zkServers: "zk:2181"
+      BK_advertisedAddress: ${BK_PUBLIC_IP}
+      BK_httpServerPort: 3182      
+    ports:
+      - "4182:4182"
+    volumes:
+      - ./data/bk2:/data
+    depends_on:
+      - zk
+      - bookie_init
+      
+
+
+    
@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>apache-bookkeeper</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>apache-bookkeeper</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>persistence-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.bookkeeper</groupId>
+            <artifactId>bookkeeper-server</artifactId>
+            <version>${org.apache.bookkeeper.version}</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.slf4j</groupId>
+                    <artifactId>slf4j-log4j12</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>testcontainers</artifactId>
+            <version>${testcontainers.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <org.apache.bookkeeper.version>4.10.0</org.apache.bookkeeper.version>
+        <testcontainers.version>1.14.3</testcontainers.version>
+    </properties>
+
+</project>
@@ -0,0 +1,149 @@
+package com.baeldung.tutorials.bookkeeper;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Optional;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.apache.bookkeeper.client.BKException;
+import org.apache.bookkeeper.client.BookKeeper;
+import org.apache.bookkeeper.client.BookKeeper.DigestType;
+import org.apache.bookkeeper.client.LedgerHandle;
+import org.apache.bookkeeper.client.api.LedgerMetadata;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.zookeeper.AsyncCallback;
+
+public class BkHelper {
+
+    private static final Log LOG = LogFactory.getLog(BkHelper.class);
+
+    public static BookKeeper createBkClient(String zkConnectionString) {
+        try {
+            return new BookKeeper(zkConnectionString);
+        } catch (Exception ex) {
+            throw new RuntimeException(ex);
+        }
+    }
+
+    /**
+     * Creates a Ledger with the given name added as custom metadata
+     * @param bk
+     * @param name
+     * @param password
+     * @return
+     */
+    public static LedgerHandle createLedger(BookKeeper bk, String name, byte[] password) {
+        try {
+            return bk.createLedger(3, 2, 2, DigestType.MAC, password, Collections.singletonMap("name", name.getBytes()));
+        } catch (Exception ex) {
+            throw new RuntimeException(ex);
+        }
+    }
+
+    /**
+     * Iterates over all available ledgers and returns the first one that has
+     * a metadata key 'name' equals to the given name
+     * @param bk
+     * @param name
+     * @return
+     * @throws Exception
+     */
+    public static Optional<Long> findLedgerByName(BookKeeper bk, String name) throws Exception {
+        Map<Long, LedgerMetadata> ledgers = new HashMap<Long, LedgerMetadata>();
+        final AtomicInteger returnCode = new AtomicInteger(BKException.Code.OK);
+        final CountDownLatch processDone = new CountDownLatch(1);
+
+        // There's no standard "list" operation. Instead, BK offers a generalized way to
+        // iterate over all available ledgers using an async visitor callback.
+        // The second callback will be called when there are no more ledgers do process or if an
+        // error occurs.
+        bk.getLedgerManager()
+          .asyncProcessLedgers(
+            (ledgerId, cb) -> collectLedgers(bk, ledgerId, cb, ledgers),
+            (rc, s, obj) -> {
+                returnCode.set(rc);
+                processDone.countDown();
+            }, 
+            null, 
+            BKException.Code.OK, BKException.Code.ReadException);
+        processDone.await(5, TimeUnit.MINUTES);
+        LOG.info("Ledgers collected: total found=" + ledgers.size());
+
+        byte[] nameBytes = name.getBytes();
+        Optional<Entry<Long, LedgerMetadata>> entry = ledgers.entrySet()
+          .stream()
+          .filter((e) -> {
+              Map<String, byte[]> meta = e.getValue()
+                .getCustomMetadata();
+              if (meta != null) {
+                  LOG.info("ledger: " + e.getKey() + ", customMeta=" + meta);
+                  byte[] data = meta.get("name");
+                  if (data != null && Arrays.equals(data, nameBytes)) {
+                      return true;
+                  } else {
+                      return false;
+                  }
+              } else {
+                  LOG.info("ledger: " + e.getKey() + ", no meta");
+                  return false;
+              }
+          })
+          .findFirst();
+        if (entry.isPresent()) {
+            return Optional.of(entry.get()
+                .getKey());
+        } else {
+            return Optional.empty();
+        }
+    }
+
+    public static void collectLedgers(BookKeeper bk, long ledgerId, AsyncCallback.VoidCallback cb, Map<Long, LedgerMetadata> ledgers) {
+        try {
+            bk.getLedgerManager()
+              .readLedgerMetadata(ledgerId)
+              .thenAccept((v) -> {
+                  LOG.debug("Got ledger metadata");
+                  ledgers.put(ledgerId, v.getValue());
+              })
+              .thenAccept((v) -> {
+                  cb.processResult(BKException.Code.OK, null, null);
+              });
+        } catch (Exception ex) {
+            throw new RuntimeException(ex);
+        }
+    }
+
+    /**
+     * Return a list with all available Ledgers
+     * @param bk
+     * @return 
+     */
+    public static List<Long> listAllLedgers(BookKeeper bk) {
+        final List<Long> ledgers = Collections.synchronizedList(new ArrayList<>());
+        final CountDownLatch processDone = new CountDownLatch(1);
+
+        bk.getLedgerManager()
+          .asyncProcessLedgers((ledgerId, cb) -> {
+              ledgers.add(ledgerId);
+              cb.processResult(BKException.Code.OK, null, null);
+          }, 
+          (rc, s, obj) -> {
+              processDone.countDown();
+          }, null, BKException.Code.OK, BKException.Code.ReadException);
+
+        try {
+            processDone.await(1, TimeUnit.MINUTES);
+            return ledgers;
+        } catch (InterruptedException ie) {
+            throw new RuntimeException(ie);
+        }
+    }
+}
@@ -0,0 +1,185 @@
+package com.baeldung.tutorials.bookkeeper;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.apache.bookkeeper.client.BookKeeper;
+import org.apache.bookkeeper.client.LedgerEntry;
+import org.apache.bookkeeper.client.LedgerHandle;
+import org.apache.bookkeeper.client.api.DigestType;
+import org.apache.bookkeeper.client.api.LedgerEntries;
+import org.apache.bookkeeper.client.api.WriteHandle;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+class BkHelperLiveTest extends BkHelper {
+    private static BookKeeper bk;
+    private byte[] ledgerPassword = "SuperS3cR37".getBytes();
+    private static final Log LOG = LogFactory.getLog(BkHelperLiveTest.class);
+
+    @BeforeAll
+    static void initBkClient() {
+        bk = createBkClient("192.168.99.101:2181");
+    }
+
+    @Test
+    void whenCreateLedger_thenSuccess() throws Exception {
+        LedgerHandle lh = bk.createLedger(BookKeeper.DigestType.MAC, ledgerPassword);
+        assertNotNull(lh);
+        assertNotNull(lh.getId());
+        LOG.info("[I33] Ledge created: id=" + lh.getId());
+    }
+
+    @Test
+    void whenCreateLedgerAsync_thenSuccess() throws Exception {
+
+        CompletableFuture<WriteHandle> cf = bk.newCreateLedgerOp()
+          .withDigestType(org.apache.bookkeeper.client.api.DigestType.MAC)
+          .withPassword("password".getBytes())
+          .execute();
+
+        WriteHandle handle = cf.get(1, TimeUnit.MINUTES);
+        assertNotNull(handle);
+        handle.close();
+
+    }
+
+    @Test
+    void whenAsyncCreateLedger_thenSuccess() throws Exception {
+        CountDownLatch latch = new CountDownLatch(1);
+        AtomicReference<LedgerHandle> handleRef = new AtomicReference<>();
+
+        bk.asyncCreateLedger(3, 2, 2, BookKeeper.DigestType.MAC, ledgerPassword, 
+          (rc, lh, ctx) -> {
+              handleRef.set(lh);
+              latch.countDown();
+          }, null, Collections.emptyMap());
+        latch.await(1, TimeUnit.MINUTES);
+        LedgerHandle lh = handleRef.get();
+        assertNotNull(lh);
+        assertFalse(lh.isClosed(), "Ledger should be writeable");
+    }
+
+    @Test
+    void whenListLedgers_thenSuccess() throws Exception {
+        List<Long> ledgers = listAllLedgers(bk);
+        assertNotNull(ledgers);
+    }
+
+    @Test
+    void whenWriteEntries_thenSuccess() throws Exception {
+        LedgerHandle lh = createLedger(bk, "myledger", ledgerPassword);
+        long start = System.currentTimeMillis();
+        for (int i = 0; i < 1000; i++) {
+            byte[] data = new String("message-" + i).getBytes();
+            lh.append(data);
+        }
+        lh.close();
+        long elapsed = System.currentTimeMillis() - start;
+        LOG.info("Entries added to ledgerId " + lh.getId() + ". count=1000, elapsed=" + elapsed);
+    }
+
+    @Test
+    void whenWriteEntriesAsync_thenSuccess() throws Exception {
+        CompletableFuture<Object> f = bk.newCreateLedgerOp()
+          .withDigestType(DigestType.MAC)
+          .withPassword(ledgerPassword)
+          .execute()
+          .thenApply((wh) -> {
+              List<CompletableFuture<Long>> ops = new ArrayList<>();
+              for (int i = 0; i < 1000; i++) {
+                  byte[] data = String.format("message-%04d", i)
+                    .getBytes();
+                  ops.add(wh.appendAsync(data));
+            }
+            return CompletableFuture.allOf(ops.stream()
+              .toArray(CompletableFuture[]::new))
+              .thenCompose((v) -> wh.closeAsync());
+        });
+        f.get(5, TimeUnit.MINUTES);
+    }
+
+    @Test
+    void whenWriteAndReadEntriesAsync_thenSuccess() throws Exception {
+        CompletableFuture<Long> f = bk.newCreateLedgerOp()
+          .withDigestType(DigestType.MAC)
+          .withPassword(ledgerPassword)
+          .execute()
+          .thenApply((wh) -> {
+              List<CompletableFuture<Long>> ops = new ArrayList<>();
+              for (int i = 0; i < 1000; i++) {
+                  byte[] data = String.format("message-%04d", i)
+                    .getBytes();
+                  ops.add(wh.appendAsync(data));
+              }
+              return CompletableFuture.allOf(ops.stream()
+                .toArray(CompletableFuture[]::new))
+                .thenCompose((v) -> wh.closeAsync())
+                .thenApply((v) -> wh.getId());
+          })
+          .thenCompose((lf) -> lf); // flatten the futures
+        Long ledgerId = f.get(5, TimeUnit.MINUTES);
+        LOG.info("Ledger created with 1000 entries: ledgerId=" + ledgerId);
+
+        // Now let's read data back...
+        CompletableFuture<LedgerEntries> ef = bk.newOpenLedgerOp()
+          .withLedgerId(ledgerId)
+          .withPassword(ledgerPassword)
+          .withDigestType(DigestType.MAC)
+          .execute()
+          .thenCompose((rh) -> {
+              return rh.readLastAddConfirmedAsync()
+                .thenCompose((lastId) -> rh.readAsync(0, lastId));
+          });
+        LedgerEntries entries = ef.get(5, TimeUnit.MINUTES);
+        
+        // Check all writes where OK
+        long count = 0;
+        Iterator<org.apache.bookkeeper.client.api.LedgerEntry> it = entries.iterator();
+        while (it.hasNext()) {
+            org.apache.bookkeeper.client.api.LedgerEntry e = it.next();
+            String msg = new String(e.getEntryBytes());
+            assertEquals(String.format("message-%04d", count), msg);
+            count++;
+        }
+        assertEquals(1000, count);
+        LOG.info("Got entries: count=" + count);
+    }
+
+    @Test
+    void whenWriteAndReadEntries_thenSuccess() throws Exception {
+        LedgerHandle lh = createLedger(bk, "myledger", ledgerPassword);
+        long start = System.currentTimeMillis();
+        for (int i = 0; i < 1000; i++) {
+            byte[] data = new String("message-" + i).getBytes();
+            lh.append(data);
+        }
+        lh.close();
+        long elapsed = System.currentTimeMillis() - start;
+        LOG.info("Entries added to ledgerId " + lh.getId() + ", elapsed=" + elapsed);
+
+        Long ledgerId = findLedgerByName(bk, "myledger").orElse(null);
+        assertNotNull(ledgerId);
+        lh = bk.openLedger(ledgerId, BookKeeper.DigestType.MAC, ledgerPassword);
+        long lastId = lh.readLastConfirmed();
+        Enumeration<LedgerEntry> entries = lh.readEntries(0, lastId);
+        while (entries.hasMoreElements()) {
+            LedgerEntry entry = entries.nextElement();
+            String msg = new String(entry.getEntry());
+            LOG.info("Entry: id=" + entry.getEntryId() + ", data=" + msg);
+        }
+    }
+}
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT"
+        class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} -
+                %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
@@ -0,0 +1,4 @@
+## Relevant articles:
+
+- [Advanced Querying in Apache Cayenne](http://www.baeldung.com/apache-cayenne-query)
+- [Introduction to Apache Cayenne ORM](http://www.baeldung.com/apache-cayenne-orm)
@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>apache-cayenne</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>apache-cayenne</name>
+    <packaging>jar</packaging>
+    <description>Introduction to Apache Cayenne</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>persistence-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.cayenne</groupId>
+            <artifactId>cayenne-server</artifactId>
+            <version>${cayenne.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.mysql</groupId>
+            <artifactId>mysql-connector-j</artifactId>
+            <version>${mysql.connector.version}</version>
+            <scope>runtime</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.cayenne.plugins</groupId>
+                <artifactId>cayenne-modeler-maven-plugin</artifactId>
+                <version>${cayenne.version}</version>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <mysql.connector.version>8.2.0</mysql.connector.version>
+        <cayenne.version>4.0.M5</cayenne.version>
+    </properties>
+
+</project>
@@ -0,0 +1,9 @@
+package com.baeldung.apachecayenne.persistent;
+
+import com.baeldung.apachecayenne.persistent.auto._Article;
+
+public class Article extends _Article {
+
+    private static final long serialVersionUID = 1L; 
+
+}
@@ -0,0 +1,9 @@
+package com.baeldung.apachecayenne.persistent;
+
+import com.baeldung.apachecayenne.persistent.auto._Author;
+
+public class Author extends _Author {
+
+    private static final long serialVersionUID = 1L; 
+
+}
@@ -0,0 +1,47 @@
+package com.baeldung.apachecayenne.persistent.auto;
+
+import org.apache.cayenne.CayenneDataObject;
+import org.apache.cayenne.exp.Property;
+
+import com.baeldung.apachecayenne.persistent.Author;
+
+/**
+ * Class _Article was generated by Cayenne.
+ * It is probably a good idea to avoid changing this class manually,
+ * since it may be overwritten next time code is regenerated.
+ * If you need to make any customizations, please use subclass.
+ */
+public abstract class _Article extends CayenneDataObject {
+
+    private static final long serialVersionUID = 1L; 
+
+    public static final String ID_PK_COLUMN = "id";
+
+    public static final Property<String> CONTENT = Property.create("content", String.class);
+    public static final Property<String> TITLE = Property.create("title", String.class);
+    public static final Property<Author> AUTHOR = Property.create("author", Author.class);
+
+    public void setContent(String content) {
+        writeProperty("content", content);
+    }
+    public String getContent() {
+        return (String)readProperty("content");
+    }
+
+    public void setTitle(String title) {
+        writeProperty("title", title);
+    }
+    public String getTitle() {
+        return (String)readProperty("title");
+    }
+
+    public void setAuthor(Author author) {
+        setToOneTarget("author", author, true);
+    }
+
+    public Author getAuthor() {
+        return (Author)readProperty("author");
+    }
+
+
+}
@@ -0,0 +1,44 @@
+package com.baeldung.apachecayenne.persistent.auto;
+
+import java.util.List;
+
+import org.apache.cayenne.CayenneDataObject;
+import org.apache.cayenne.exp.Property;
+
+import com.baeldung.apachecayenne.persistent.Article;
+
+/**
+ * Class _Author was generated by Cayenne.
+ * It is probably a good idea to avoid changing this class manually,
+ * since it may be overwritten next time code is regenerated.
+ * If you need to make any customizations, please use subclass.
+ */
+public abstract class _Author extends CayenneDataObject {
+
+    private static final long serialVersionUID = 1L; 
+
+    public static final String ID_PK_COLUMN = "id";
+
+    public static final Property<String> NAME = Property.create("name", String.class);
+    public static final Property<List<Article>> ARTICLES = Property.create("articles", List.class);
+
+    public void setName(String name) {
+        writeProperty("name", name);
+    }
+    public String getName() {
+        return (String)readProperty("name");
+    }
+
+    public void addToArticles(Article obj) {
+        addToManyTarget("articles", obj, true);
+    }
+    public void removeFromArticles(Article obj) {
+        removeToManyTarget("articles", obj, true);
+    }
+    @SuppressWarnings("unchecked")
+    public List<Article> getArticles() {
+        return (List<Article>)readProperty("articles");
+    }
+
+
+}
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<domain project-version="9">
+	<map name="datamap"/>
+
+	<node name="datanode"
+		 factory="org.apache.cayenne.configuration.server.XMLPoolingDataSourceFactory"
+		 schema-update-strategy="org.apache.cayenne.access.dbsync.CreateIfNoSchemaStrategy"
+		>
+		<map-ref name="datamap"/>
+		<data-source>
+			<driver value="com.mysql.jdbc.Driver"/>
+			<url value="jdbc:mysql://localhost:3306/intro_cayenne"/>
+			<connectionPool min="1" max="1"/>
+			<login userName="root" password="root"/>
+		</data-source>
+	</node>
+</domain>
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+<data-map xmlns="http://cayenne.apache.org/schema/9/modelMap"
+	 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	 xsi:schemaLocation="http://cayenne.apache.org/schema/9/modelMap http://cayenne.apache.org/schema/9/modelMap.xsd"
+	 project-version="9">
+	<property name="defaultPackage" value="com.baeldung.apachecayenne.persistent"/>
+	<db-entity name="article" catalog="intro_cayenne">
+		<db-attribute name="author_id" type="INTEGER" isMandatory="true" length="10"/>
+		<db-attribute name="content" type="VARCHAR" isMandatory="true" length="254"/>
+		<db-attribute name="id" type="INTEGER" isPrimaryKey="true" isGenerated="true" isMandatory="true" length="10"/>
+		<db-attribute name="title" type="VARCHAR" isMandatory="true" length="254"/>
+	</db-entity>
+	<db-entity name="author" catalog="intro_cayenne">
+		<db-attribute name="id" type="INTEGER" isPrimaryKey="true" isGenerated="true" isMandatory="true" length="10"/>
+		<db-attribute name="name" type="VARCHAR" isMandatory="true" length="254"/>
+	</db-entity>
+	<obj-entity name="Article" className="com.baeldung.apachecayenne.persistent.Article" dbEntityName="article">
+		<obj-attribute name="content" type="java.lang.String" db-attribute-path="content"/>
+		<obj-attribute name="title" type="java.lang.String" db-attribute-path="title"/>
+	</obj-entity>
+	<obj-entity name="Author" className="com.baeldung.apachecayenne.persistent.Author" dbEntityName="author">
+		<obj-attribute name="name" type="java.lang.String" db-attribute-path="name"/>
+	</obj-entity>
+	<db-relationship name="author" source="article" target="author" toMany="false">
+		<db-attribute-pair source="author_id" target="id"/>
+	</db-relationship>
+	<db-relationship name="articles" source="author" target="article" toMany="true">
+		<db-attribute-pair source="id" target="author_id"/>
+	</db-relationship>
+	<obj-relationship name="author" source="Article" target="Author" deleteRule="Nullify" db-relationship-path="author"/>
+	<obj-relationship name="articles" source="Author" target="Article" deleteRule="Deny" db-relationship-path="articles"/>
+</data-map>
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
@@ -0,0 +1,256 @@
+package com.baeldung.apachecayenne;
+
+import com.baeldung.apachecayenne.persistent.Author;
+import org.apache.cayenne.ObjectContext;
+import org.apache.cayenne.QueryResponse;
+import org.apache.cayenne.configuration.server.ServerRuntime;
+import org.apache.cayenne.exp.Expression;
+import org.apache.cayenne.exp.ExpressionFactory;
+import org.apache.cayenne.query.*;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class CayenneAdvancedOperationLiveTest {
+    private static ObjectContext context = null;
+
+    @BeforeClass
+    public static void setupTheCayenneContext() {
+        ServerRuntime cayenneRuntime = ServerRuntime.builder()
+          .addConfig("cayenne-project.xml")
+          .build();
+        context = cayenneRuntime.newContext();
+    }
+
+    @Before
+    public void saveThreeAuthors() {
+        Author authorOne = context.newObject(Author.class);
+        authorOne.setName("Paul Xavier");
+        Author authorTwo = context.newObject(Author.class);
+        authorTwo.setName("pAuL Smith");
+        Author authorThree = context.newObject(Author.class);
+        authorThree.setName("Vicky Sarra");
+        context.commitChanges();
+    }
+
+    @After
+    public void deleteAllAuthors() {
+        SQLTemplate deleteAuthors = new SQLTemplate(Author.class, "delete from author");
+        context.performGenericQuery(deleteAuthors);
+    }
+
+    @Test
+    public void givenAuthors_whenFindAllSQLTmplt_thenWeGetThreeAuthors() {
+        SQLTemplate select = new SQLTemplate(Author.class, "select * from Author");
+        List<Author> authors = context.performQuery(select);
+
+        assertEquals(authors.size(), 3);
+    }
+
+    @Test
+    public void givenAuthors_whenFindByNameSQLTmplt_thenWeGetOneAuthor() {
+        SQLTemplate select = new SQLTemplate(Author.class, "select * from Author where name = 'Vicky Sarra'");
+        List<Author> authors = context.performQuery(select);
+        Author author = authors.get(0);
+
+        assertEquals(authors.size(), 1);
+        assertEquals(author.getName(), "Vicky Sarra");
+    }
+
+    @Test
+    public void givenAuthors_whenLikeSltQry_thenWeGetOneAuthor() {
+        Expression qualifier = ExpressionFactory.likeExp(Author.NAME.getName(), "Paul%");
+        SelectQuery query = new SelectQuery(Author.class, qualifier);
+        List<Author> authorsTwo = context.performQuery(query);
+
+        assertEquals(authorsTwo.size(), 1);
+    }
+
+    @Test
+    public void givenAuthors_whenCtnsIgnorCaseSltQry_thenWeGetTwoAuthors() {
+        Expression qualifier = ExpressionFactory.containsIgnoreCaseExp(Author.NAME.getName(), "Paul");
+        SelectQuery query = new SelectQuery(Author.class, qualifier);
+        List<Author> authors = context.performQuery(query);
+
+        assertEquals(authors.size(), 2);
+    }
+
+    @Test
+    public void givenAuthors_whenCtnsIgnorCaseEndsWSltQry_thenWeGetTwoAuthors() {
+        Expression qualifier = ExpressionFactory.containsIgnoreCaseExp(Author.NAME.getName(), "Paul")
+                .andExp(ExpressionFactory.endsWithExp(Author.NAME.getName(), "h"));
+        SelectQuery query = new SelectQuery(Author.class, qualifier);
+        List<Author> authors = context.performQuery(query);
+
+        Author author = authors.get(0);
+
+        assertEquals(authors.size(), 1);
+        assertEquals(author.getName(), "pAuL Smith");
+    }
+
+    @Test
+    public void givenAuthors_whenAscOrderingSltQry_thenWeGetOrderedAuthors() {
+        SelectQuery query = new SelectQuery(Author.class);
+        query.addOrdering(Author.NAME.asc());
+
+        List<Author> authors = query.select(context);
+        Author firstAuthor = authors.get(0);
+
+        assertEquals(authors.size(), 3);
+        assertEquals(firstAuthor.getName(), "Paul Xavier");
+    }
+
+    @Test
+    public void givenAuthors_whenDescOrderingSltQry_thenWeGetOrderedAuthors() {
+        SelectQuery query = new SelectQuery(Author.class);
+        query.addOrdering(Author.NAME.desc());
+
+        List<Author> authors = query.select(context);
+        Author firstAuthor = authors.get(0);
+
+        assertEquals(authors.size(), 3);
+        assertEquals(firstAuthor.getName(), "pAuL Smith");
+    }
+
+    @Test
+    public void givenAuthors_onContainsObjS_thenWeGetOneRecord() {
+        List<Author> authors = ObjectSelect.query(Author.class)
+          .where(Author.NAME.contains("Paul"))
+          .select(context);
+
+        assertEquals(authors.size(), 1);
+    }
+
+    @Test
+    public void givenAuthors_whenLikeObjS_thenWeGetTwoAuthors() {
+        List<Author> authors = ObjectSelect.query(Author.class)
+          .where(Author.NAME.likeIgnoreCase("Paul%"))
+          .select(context);
+
+        assertEquals(authors.size(), 2);
+    }
+
+    @Test
+    public void givenTwoAuthor_whenEndsWithObjS_thenWeGetOrderedAuthors() {
+        List<Author> authors = ObjectSelect.query(Author.class)
+          .where(Author.NAME.endsWith("Sarra"))
+          .select(context);
+        Author firstAuthor = authors.get(0);
+
+        assertEquals(authors.size(), 1);
+        assertEquals(firstAuthor.getName(), "Vicky Sarra");
+    }
+
+    @Test
+    public void givenTwoAuthor_whenInObjS_thenWeGetAuthors() {
+        List<String> names = Arrays.asList("Paul Xavier", "pAuL Smith", "Vicky Sarra");
+        List<Author> authors = ObjectSelect.query(Author.class)
+                .where(Author.NAME.in(names))
+                .select(context);
+
+        assertEquals(authors.size(), 3);
+    }
+
+    @Test
+    public void givenTwoAuthor_whenNinObjS_thenWeGetAuthors() {
+        List<String> names = Arrays.asList("Paul Xavier", "pAuL Smith");
+        List<Author> authors = ObjectSelect.query(Author.class)
+                .where(Author.NAME.nin(names))
+                .select(context);
+        Author author = authors.get(0);
+
+        assertEquals(authors.size(), 1);
+        assertEquals(author.getName(), "Vicky Sarra");
+    }
+
+    @Test
+    public void givenTwoAuthor_whenIsNotNullObjS_thenWeGetAuthors() {
+        List<Author> authors = ObjectSelect.query(Author.class)
+          .where(Author.NAME.isNotNull())
+          .select(context);
+
+        assertEquals(authors.size(), 3);
+    }
+
+    @Test
+    public void givenAuthors_whenFindAllEJBQL_thenWeGetThreeAuthors() {
+        EJBQLQuery query = new EJBQLQuery("select a FROM Author a");
+        List<Author> authors = context.performQuery(query);
+
+        assertEquals(authors.size(), 3);
+    }
+
+    @Test
+    public void givenAuthors_whenFindByNameEJBQL_thenWeGetOneAuthor() {
+        EJBQLQuery query = new EJBQLQuery("select a FROM Author a WHERE a.name = 'Vicky Sarra'");
+        List<Author> authors = context.performQuery(query);
+        Author author = authors.get(0);
+
+        assertEquals(authors.size(), 1);
+        assertEquals(author.getName(), "Vicky Sarra");
+    }
+
+    @Test
+    public void givenAuthors_whenUpdadingByNameEJBQL_thenWeGetTheUpdatedAuthor() {
+        EJBQLQuery query = new EJBQLQuery("UPDATE Author AS a SET a.name = 'Vicky Edison' WHERE a.name = 'Vicky Sarra'");
+        QueryResponse queryResponse = context.performGenericQuery(query);
+
+        EJBQLQuery queryUpdatedAuthor = new EJBQLQuery("select a FROM Author a WHERE a.name = 'Vicky Edison'");
+        List<Author> authors = context.performQuery(queryUpdatedAuthor);
+        Author author = authors.get(0);
+
+        assertNotNull(author);
+    }
+
+    @Test
+    public void givenAuthors_whenSeletingNamesEJBQL_thenWeGetListWithSizeThree() {
+        String [] args = {"Paul Xavier", "pAuL Smith", "Vicky Sarra"};
+        List<String> names = Arrays.asList(args);
+        EJBQLQuery query = new EJBQLQuery("select a.name FROM Author a");
+        List<String> nameList = context.performQuery(query);
+
+        Collections.sort(names);
+        Collections.sort(nameList);
+
+        assertEquals(names.size(), 3);
+        assertEquals(nameList.size(), 3);
+        assertEquals(names, nameList);
+    }
+
+    @Test
+    public void givenAuthors_whenDeletingAllWithEJB_thenWeGetNoAuthor() {
+        EJBQLQuery deleteQuery = new EJBQLQuery("delete FROM Author");
+        EJBQLQuery findAllQuery = new EJBQLQuery("select a FROM Author a");
+
+        context.performQuery(deleteQuery);
+        List<Author> objects = context.performQuery(findAllQuery);
+
+        assertEquals(objects.size(), 0);
+    }
+
+    @Test
+    public void givenAuthors_whenInsertingSQLExec_thenWeGetNewAuthor() {
+        int inserted = SQLExec
+          .query("INSERT INTO Author (name) VALUES ('Baeldung')")
+          .update(context);
+
+        assertEquals(inserted, 1);
+    }
+
+    @Test
+    public void givenAuthors_whenUpdatingSQLExec_thenItsUpdated() {
+        int updated = SQLExec
+          .query("UPDATE Author SET name = 'Baeldung' WHERE name = 'Vicky Sarra'")
+          .update(context);
+
+        assertEquals(updated, 1);
+    }
+}
@@ -0,0 +1,131 @@
+package com.baeldung.apachecayenne;
+
+import com.baeldung.apachecayenne.persistent.Article;
+import com.baeldung.apachecayenne.persistent.Author;
+import org.apache.cayenne.ObjectContext;
+import org.apache.cayenne.configuration.server.ServerRuntime;
+import org.apache.cayenne.query.ObjectSelect;
+import org.apache.cayenne.query.SQLTemplate;
+import org.junit.After;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.List;
+
+import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+
+public class CayenneOperationLiveTest {
+    private static ObjectContext context = null;
+
+    @BeforeClass
+    public static void setupTheCayenneContext() {
+        ServerRuntime cayenneRuntime = ServerRuntime.builder()
+                .addConfig("cayenne-project.xml")
+                .build();
+        context = cayenneRuntime.newContext();
+    }
+
+    @After
+    public void deleteAllRecords() {
+        SQLTemplate deleteArticles = new SQLTemplate(Article.class, "delete from article");
+        SQLTemplate deleteAuthors = new SQLTemplate(Author.class, "delete from author");
+
+        context.performGenericQuery(deleteArticles);
+        context.performGenericQuery(deleteAuthors);
+    }
+
+    @Test
+    public void givenAuthor_whenInsert_thenWeGetOneRecordInTheDatabase() {
+        Author author = context.newObject(Author.class);
+        author.setName("Paul");
+
+        context.commitChanges();
+
+        long records = ObjectSelect.dataRowQuery(Author.class).selectCount(context);
+        assertEquals(1, records);
+    }
+
+    @Test
+    public void givenAuthor_whenInsert_andQueryByFirstName_thenWeGetTheAuthor() {
+        Author author = context.newObject(Author.class);
+        author.setName("Paul");
+
+        context.commitChanges();
+
+        Author expectedAuthor = ObjectSelect.query(Author.class)
+                .where(Author.NAME.eq("Paul"))
+                .selectOne(context);
+
+        assertEquals("Paul", expectedAuthor.getName());
+    }
+
+    @Test
+    public void givenTwoAuthor_whenInsert_andQueryAll_thenWeGetTwoAuthors() {
+        Author firstAuthor = context.newObject(Author.class);
+        firstAuthor.setName("Paul");
+
+        Author secondAuthor = context.newObject(Author.class);
+        secondAuthor.setName("Ludovic");
+
+        context.commitChanges();
+
+        List<Author> authors = ObjectSelect.query(Author.class).select(context);
+        assertEquals(2, authors.size());
+    }
+
+    @Test
+    public void givenAuthor_whenUpdating_thenWeGetAnUpatedeAuthor() {
+        Author author = context.newObject(Author.class);
+        author.setName("Paul");
+        context.commitChanges();
+
+        Author expectedAuthor = ObjectSelect.query(Author.class)
+                .where(Author.NAME.eq("Paul"))
+                .selectOne(context);
+        expectedAuthor.setName("Garcia");
+        context.commitChanges();
+
+        assertEquals(author.getName(), expectedAuthor.getName());
+    }
+
+    @Test
+    public void givenAuthor_whenDeleting_thenWeLostHisDetails() {
+        Author author = context.newObject(Author.class);
+        author.setName("Paul");
+        context.commitChanges();
+
+        Author savedAuthor = ObjectSelect.query(Author.class)
+                .where(Author.NAME.eq("Paul")).selectOne(context);
+        if(savedAuthor != null) {
+            context.deleteObjects(author);
+            context.commitChanges();
+        }
+
+        Author expectedAuthor = ObjectSelect.query(Author.class)
+                .where(Author.NAME.eq("Paul")).selectOne(context);
+        assertNull(expectedAuthor);
+    }
+
+    @Test
+    public void givenAuthor_whenAttachingToArticle_thenTheRelationIsMade() {
+        Author author = context.newObject(Author.class);
+        author.setName("Paul");
+
+        Article article = context.newObject(Article.class);
+        article.setTitle("My post title");
+        article.setContent("The content");
+        article.setAuthor(author);
+
+        context.commitChanges();
+
+        Author expectedAuthor = ObjectSelect.query(Author.class)
+                .where(Author.NAME.eq("Paul"))
+                .selectOne(context);
+
+        Article expectedArticle = (expectedAuthor.getArticles()).get(0);
+        assertEquals(article.getTitle(), expectedArticle.getTitle());
+    }
+
+}
@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Getting Started With Apache Derby](https://www.baeldung.com/java-apache-derby)
@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>apache-derby</artifactId>
+
+    <parent>
+        <artifactId>persistence-modules</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/org.apache.derby/derby -->
+        <dependency>
+            <groupId>org.apache.derby</groupId>
+            <artifactId>derby</artifactId>
+            <version>${derby.version}</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.apache.derby/derbyclient -->
+        <dependency>
+            <groupId>org.apache.derby</groupId>
+            <artifactId>derbyclient</artifactId>
+            <version>${derbyclient.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <derby.version>10.13.1.1</derby.version>
+        <derbyclient.version>10.13.1.1</derbyclient.version>
+    </properties>
+
+</project>
@@ -0,0 +1,39 @@
+package com.baeldung.derby;
+
+import java.sql.*;
+
+/**
+ * Created by arash on 14.10.21.
+ */
+
+public class DerbyApplicationDemo {
+    public static void main(String[] args) {
+        runner("jdbc:derby:baeldung;create=true");
+    }
+
+    private static void runner(String urlConnection) {
+        try {
+            Connection con = DriverManager.getConnection(urlConnection);
+            Statement statement = con.createStatement();
+            if (!isTableExists("authors", con)) {
+                String createSQL = "CREATE TABLE authors (id INT PRIMARY KEY,first_name VARCHAR(255),last_name VARCHAR(255))";
+                statement.execute(createSQL);
+                String insertSQL = "INSERT INTO authors VALUES (1, 'arash','ariani')";
+                statement.execute(insertSQL);
+            }
+            String selectSQL = "SELECT * FROM authors";
+            ResultSet result = statement.executeQuery(selectSQL);
+            while (result.next()) {
+                // use result here
+            }
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private static boolean isTableExists(String tableName, Connection connection) throws SQLException {
+        DatabaseMetaData meta = connection.getMetaData();
+        ResultSet result = meta.getTables(null, null, tableName.toUpperCase(), null);
+        return result.next();
+    }
+}
--- a/Show More
+++ b/Show More