Merge pull request #1 from eugenp/master

Merge remote changes

algorithms/src/main/java/com/baeldung/algorithms/BinarySearch.java

@@ -0,0 +1,26 @@
+public class BinarySearch {
+
+    public int runBinarySearch() {
+        int[] sortedArray = { 0, 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 9 };
+        int key = 6;
+
+        int low = 0;
+        int high = sortedArray.length - 1;
+        int index = Integer.MAX_VALUE;
+
+        while (low <= high) {
+
+            int mid = (low + high) / 2;
+
+            if (sortedArray[mid] < key) {
+                low = mid + 1;
+            } else if (sortedArray[mid] > key) {
+                high = mid - 1;
+            } else if (sortedArray[mid] == key) {
+                index = mid;
+                break;
+            }
+        }
+        return index;
+    }
+}

algorithms/src/test/java/algorithms/BinarySearchTest.java

@@ -0,0 +1,14 @@
+import org.junit.Assert;
+import org.junit.Test;
+
+
+public class BinarySearchTest {
+
+    @Test
+    public void givenASortedArrayOfIntegers_whenBinarySearchRunForANumber_thenGetIndexOfTheNumber() {
+        BinarySearch binSearch = new BinarySearch();
+        int expectedIndexForSearchKey = 7;
+        Assert.assertEquals(expectedIndexForSearchKey, binSearch.runBinarySearch());
+    }
+
+}

apache-shiro/.gitignore

@@ -0,0 +1,4 @@
+
+/.idea/
+/target/
+/apache-shiro.iml

apache-shiro/pom.xml

@@ -0,0 +1,65 @@
+<?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>
+
+    <groupId>com.baeldung</groupId>
+    <artifactId>apache-shiro</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <properties>
+        <apache-shiro-core-version>1.4.0</apache-shiro-core-version>
+        <log4j-version>1.2.17</log4j-version>
+        <slf4j-version>1.7.25</slf4j-version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.shiro</groupId>
+            <artifactId>shiro-core</artifactId>
+            <version>${apache-shiro-core-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>jcl-over-slf4j</artifactId>
+            <version>${slf4j-version}</version>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-log4j12</artifactId>
+            <version>${slf4j-version}</version>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>log4j</groupId>
+            <artifactId>log4j</artifactId>
+            <version>${log4j-version}</version>
+            <scope>runtime</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.6.2</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    
+</project>

apache-shiro/src/main/java/com/baeldung/Main.java

@@ -0,0 +1,85 @@
+package com.baeldung;
+
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.authc.*;
+import org.apache.shiro.mgt.DefaultSecurityManager;
+import org.apache.shiro.mgt.SecurityManager;
+import org.apache.shiro.realm.Realm;
+import org.apache.shiro.realm.text.IniRealm;
+import org.apache.shiro.session.Session;
+import org.apache.shiro.subject.Subject;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class Main {
+
+    private static final transient Logger log = LoggerFactory.getLogger(Main.class);
+
+    public static void main(String[] args) {
+
+        Realm realm = new MyCustomRealm();
+        SecurityManager securityManager = new DefaultSecurityManager(realm);
+
+        SecurityUtils.setSecurityManager(securityManager);
+        Subject currentUser = SecurityUtils.getSubject();
+
+        if (!currentUser.isAuthenticated()) {
+          UsernamePasswordToken token 
+            = new UsernamePasswordToken("user", "password");
+          token.setRememberMe(true);
+          try {
+              currentUser.login(token);
+          } catch (UnknownAccountException uae) {
+              log.error("Username Not Found!", uae);
+          } catch (IncorrectCredentialsException ice) {
+              log.error("Invalid Credentials!", ice);
+          } catch (LockedAccountException lae) {
+              log.error("Your Account is Locked!", lae);
+          } catch (AuthenticationException ae) {
+              log.error("Unexpected Error!", ae);
+          }
+        }
+
+        log.info("User [" + currentUser.getPrincipal() + "] logged in successfully.");
+
+        if (currentUser.hasRole("admin")) {
+            log.info("Welcome Admin");
+        } else if(currentUser.hasRole("editor")) {
+            log.info("Welcome, Editor!");
+        } else if(currentUser.hasRole("author")) {
+            log.info("Welcome, Author");
+        } else {
+            log.info("Welcome, Guest");
+        }
+
+        if(currentUser.isPermitted("articles:compose")) {
+            log.info("You can compose an article");
+        } else {
+            log.info("You are not permitted to compose an article!");
+        }
+
+        if(currentUser.isPermitted("articles:save")) {
+            log.info("You can save articles");
+        } else {
+            log.info("You can not save articles");
+        }
+
+        if(currentUser.isPermitted("articles:publish")) {
+            log.info("You can publish articles");
+        } else {
+            log.info("You can not publish articles");
+        }
+
+        Session session = currentUser.getSession();
+        session.setAttribute("key", "value");
+        String value = (String) session.getAttribute("key");
+        if (value.equals("value")) {
+            log.info("Retrieved the correct value! [" + value + "]");
+        }
+
+        currentUser.logout();
+
+        System.exit(0);
+    }
+
+}

apache-shiro/src/main/java/com/baeldung/MyCustomRealm.java

@@ -0,0 +1,102 @@
+package com.baeldung;
+
+import org.apache.shiro.authc.*;
+import org.apache.shiro.authz.AuthorizationInfo;
+import org.apache.shiro.authz.SimpleAuthorizationInfo;
+import org.apache.shiro.realm.jdbc.JdbcRealm;
+import org.apache.shiro.subject.PrincipalCollection;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.*;
+
+public class MyCustomRealm extends JdbcRealm {
+
+    private Map<String, String> credentials = new HashMap<>();
+    private Map<String, Set<String>> roles = new HashMap<>();
+    private Map<String, Set<String>> perm = new HashMap<>();
+
+    {
+      credentials.put("user", "password");
+      credentials.put("user2", "password2");
+      credentials.put("user3", "password3");
+
+      roles.put("user", new HashSet<>(Arrays.asList("admin")));
+      roles.put("user2", new HashSet<>(Arrays.asList("editor")));
+      roles.put("user3", new HashSet<>(Arrays.asList("author")));
+
+      perm.put("admin", new HashSet<>(Arrays.asList("*")));
+      perm.put("editor", new HashSet<>(Arrays.asList("articles:*")));
+      perm.put("author",
+        new HashSet<>(Arrays.asList("articles:compose",
+          "articles:save")));
+
+    }
+
+    @Override
+    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token)
+      throws AuthenticationException {
+
+        UsernamePasswordToken uToken = (UsernamePasswordToken) token;
+
+        if(uToken.getUsername() == null
+          || uToken.getUsername().isEmpty()
+          || !credentials.containsKey(uToken.getUsername())
+          ) {
+            throw new UnknownAccountException("username not found!");
+        }
+
+
+        return new SimpleAuthenticationInfo(
+          uToken.getUsername(), credentials.get(uToken.getUsername()),
+          getName());
+    }
+
+    @Override
+    protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
+        Set<String> roleNames = new HashSet<>();
+        Set<String> permissions = new HashSet<>();
+
+        principals.forEach(p -> {
+            try {
+                Set<String> roles = getRoleNamesForUser(null, (String) p);
+                roleNames.addAll(roles);
+                permissions.addAll(getPermissions(null, null,roles));
+            } catch (SQLException e) {
+                e.printStackTrace();
+            }
+        });
+
+        SimpleAuthorizationInfo info = new SimpleAuthorizationInfo(roleNames);
+        info.setStringPermissions(permissions);
+        return info;
+    }
+
+    @Override
+    protected Set<String> getRoleNamesForUser(Connection conn, String username) throws SQLException {
+        if(!roles.containsKey(username)) {
+            throw new SQLException("username not found!");
+        }
+
+       return roles.get(username);
+    }
+
+    @Override
+    protected Set<String> getPermissions(Connection conn, String username, Collection<String> roleNames) throws SQLException {
+        for (String role : roleNames) {
+            if (!perm.containsKey(role)) {
+                throw new SQLException("role not found!");
+            }
+        }
+
+        Set<String> finalSet = new HashSet<>();
+        for (String role : roleNames) {
+            finalSet.addAll(perm.get(role));
+        }
+
+        return finalSet;
+    }
+
+}

apache-shiro/src/main/resources/log4j.properties

@@ -0,0 +1,12 @@
+log4j.rootLogger=INFO, stdout
+
+log4j.appender.stdout=org.apache.log4j.ConsoleAppender
+log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
+log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m %n
+
+log4j.logger.org.apache=WARN
+
+log4j.logger.org.apache.shiro=INFO
+
+log4j.logger.org.apache.shiro.util.ThreadContext=WARN
+log4j.logger.org.apache.shiro.cache.ehcache.EhCache=WARN

apache-shiro/src/main/resources/shiro.ini

@@ -0,0 +1,9 @@
+[users]
+user = password,admin
+user2 = password2,editor
+user3 = password3,author
+
+[roles]
+admin = *
+editor = articles:*
+author = articles:compose,articles:save

apache-velocity/src/main/webapp/WEB-INF/velocity.properties

@@ -1,4 +1,4 @@
 resource.loader=webapp
 webapp.resource.loader.class=org.apache.velocity.tools.view.WebappResourceLoader
-webapp.resource.loader.path = .
+webapp.resource.loader.path = 
 webapp.resource.loader.cache = true

asciidoctor/README.md

@@ -1,3 +1,4 @@
 ### Relevant articles
 
-- [Introduction to Asciidoctor](http://www.baeldung.com/introduction-to-asciidoctor)
+- [Introduction to Asciidoctor](http://www.baeldung.com/introduction-to-asciidoctor)
+- [Generating a Book with Asciidoctor](http://www.baeldung.com/asciidoctor-book)

bootique/config.yml

@@ -0,0 +1,11 @@
+log:
+  level: warn
+  appenders:
+    - type: file
+      logFormat: '%c{20}: %m%n'
+      file: /home/logger.log
+
+jetty:
+  context: /hello
+  connector:
+    port: 10001

bootique/dependency-reduced-pom.xml

@@ -0,0 +1,50 @@
+<?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/maven-v4_0_0.xsd">
+  <parent>
+    <artifactId>bootique-parent</artifactId>
+    <groupId>io.bootique.parent</groupId>
+    <version>0.12</version>
+  </parent>
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.baeldung.bootique</groupId>
+  <artifactId>bootique</artifactId>
+  <name>bootique</name>
+  <version>1.0-SNAPSHOT</version>
+  <url>http://maven.apache.org</url>
+  <build>
+    <plugins>
+      <plugin>
+        <artifactId>maven-shade-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+  <dependencies>
+    <dependency>
+      <groupId>io.bootique</groupId>
+      <artifactId>bootique-test</artifactId>
+      <version>0.23</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>3.8.1</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>io.bootique.bom</groupId>
+        <artifactId>bootique-bom</artifactId>
+        <version>0.23</version>
+        <type>pom</type>
+        <scope>import</scope>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+  <properties>
+    <main.class>com.baeldung.bootique.App</main.class>
+  </properties>
+</project>
+

bootique/pom.xml

@@ -0,0 +1,66 @@
+<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/maven-v4_0_0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>com.baeldung.bootique</groupId>
+	<artifactId>bootique</artifactId>
+	<packaging>jar</packaging>
+	<version>1.0-SNAPSHOT</version>
+	<name>bootique</name>
+	<url>http://maven.apache.org</url>
+
+	<properties>
+		<main.class>com.baeldung.bootique.App</main.class>
+	</properties>
+
+	<parent>
+		<groupId>io.bootique.parent</groupId>
+		<artifactId>bootique-parent</artifactId>
+		<version>0.12</version>
+	</parent>
+
+	<dependencyManagement>
+		<dependencies>
+			<dependency>
+				<groupId>io.bootique.bom</groupId>
+				<artifactId>bootique-bom</artifactId>
+				<version>0.23</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
+		</dependencies>
+	</dependencyManagement>
+
+	<dependencies>
+		<dependency>
+			<groupId>io.bootique.jersey</groupId>
+			<artifactId>bootique-jersey</artifactId>
+			<scope>compile</scope>
+		</dependency>
+		<dependency>
+			<groupId>io.bootique.logback</groupId>
+			<artifactId>bootique-logback</artifactId>
+			<scope>compile</scope>
+		</dependency>
+		<dependency>
+			<groupId>io.bootique</groupId>
+			<artifactId>bootique-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<version>4.12</version>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-shade-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

bootique/src/main/java/com/baeldung/bootique/App.java

@@ -0,0 +1,41 @@
+package com.baeldung.bootique;
+
+import com.baeldung.bootique.module.ModuleBinder;
+import com.baeldung.bootique.router.IndexController;
+import com.baeldung.bootique.router.SaveController;
+import com.google.inject.Module;
+import io.bootique.Bootique;
+import io.bootique.jersey.JerseyModule;
+import io.bootique.log.BootLogger;
+
+import java.util.function.Supplier;
+
+public class App {
+
+    public static void main(String[] args) {
+        Module module = binder -> JerseyModule.extend(binder).addResource(IndexController.class)
+          .addResource(SaveController.class);
+        Bootique.app(args).module(module).module(ModuleBinder.class).bootLogger(new BootLogger() {
+            @Override
+            public void trace(Supplier<String> arg0) {
+                // ...
+            }
+
+            @Override
+            public void stdout(String arg0) {
+                // ...
+            }
+
+            @Override
+            public void stderr(String arg0, Throwable arg1) {
+                // ...
+            }
+
+            @Override
+            public void stderr(String arg0) {
+                // ...
+            }
+        }).autoLoadModules().exec();
+    }
+
+}

bootique/src/main/java/com/baeldung/bootique/module/ModuleBinder.java

@@ -0,0 +1,15 @@
+package com.baeldung.bootique.module;
+
+import com.baeldung.bootique.service.HelloService;
+import com.baeldung.bootique.service.impl.HelloServiceImpl;
+import com.google.inject.Binder;
+import com.google.inject.Module;
+
+public class ModuleBinder implements Module {
+
+    @Override
+    public void configure(Binder binder) {
+        binder.bind(HelloService.class).to(HelloServiceImpl.class);
+    }
+
+}

bootique/src/main/java/com/baeldung/bootique/module/ModuleProvider.java

@@ -0,0 +1,13 @@
+package com.baeldung.bootique.module;
+
+import com.google.inject.Module;
+import io.bootique.BQModuleProvider;
+
+public class ModuleProvider implements BQModuleProvider {
+
+    @Override
+    public Module module() {
+        return new ModuleBinder();
+    }
+
+}

bootique/src/main/java/com/baeldung/bootique/router/IndexController.java

@@ -0,0 +1,14 @@
+package com.baeldung.bootique.router;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+
+@Path("/")
+public class IndexController {
+
+    @GET
+    public String index() {
+        return "Hello, baeldung!";
+    }
+
+}

bootique/src/main/java/com/baeldung/bootique/router/SaveController.java

@@ -0,0 +1,20 @@
+package com.baeldung.bootique.router;
+
+import com.baeldung.bootique.service.HelloService;
+import com.google.inject.Inject;
+
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+
+@Path("/save")
+public class SaveController {
+
+    @Inject
+    HelloService helloService;
+
+    @POST
+    public String save() {
+        return "Data Saved!";
+    }
+
+}

bootique/src/main/java/com/baeldung/bootique/service/HelloService.java

@@ -0,0 +1,7 @@
+package com.baeldung.bootique.service;
+
+public interface HelloService {
+
+	boolean save();
+
+}

bootique/src/main/java/com/baeldung/bootique/service/impl/HelloServiceImpl.java

@@ -0,0 +1,12 @@
+package com.baeldung.bootique.service.impl;
+
+import com.baeldung.bootique.service.HelloService;
+
+public class HelloServiceImpl implements HelloService {
+
+	@Override
+	public boolean save() {
+		return true;
+	}
+
+}

bootique/src/main/resources/META-INF/services/io.bootique.BQModuleProvider

@@ -0,0 +1 @@
+com.baeldung.bootique.module.ModuleProvider

bootique/src/test/java/com/baeldung/bootique/AppTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.bootique;
+
+import com.baeldung.bootique.service.HelloService;
+import io.bootique.BQRuntime;
+import io.bootique.test.junit.BQDaemonTestFactory;
+import io.bootique.test.junit.BQTestFactory;
+import org.junit.Rule;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class AppTest {
+
+    @Rule
+    public BQTestFactory bqTestFactory = new BQTestFactory();
+
+    @Rule
+    public BQDaemonTestFactory bqDaemonTestFactory = new BQDaemonTestFactory();
+
+    @Test
+    public void givenService_expectBoolen() {
+        BQRuntime runtime = bqTestFactory.app("--server").autoLoadModules().createRuntime();
+        HelloService service = runtime.getInstance(HelloService.class);
+        assertEquals(true, service.save());
+    }
+
+}

core-java-9/src/main/java/com/baeldung/java9/process/ServiceMain.java

@@ -6,7 +6,7 @@ public class ServiceMain {
 
     public static void main(String[] args) throws InterruptedException {
         ProcessHandle thisProcess = ProcessHandle.current();
-        long pid = thisProcess.getPid();
+        long pid = thisProcess.pid();
 
         Optional<String[]> opArgs = Optional.ofNullable(args);
         String procName = opArgs.map(str -> str.length > 0 ? str[0] : null).orElse(System.getProperty("sun.java.command"));

core-java-9/src/test/java/com/baeldung/java9/language/Java9ObjectsAPIUnitTest.java

@@ -0,0 +1,86 @@
+package com.baeldung.java9.language;
+
+import org.junit.Test;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+import static org.hamcrest.Matchers.*;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class Java9ObjectsAPIUnitTest {
+
+    private List<String> aMethodReturningNullList(){
+        return null;
+    }
+
+    @Test
+    public void givenNullObject_whenRequireNonNullElse_thenElse(){
+        List<String> aList = Objects.<List>requireNonNullElse(
+                aMethodReturningNullList(), Collections.EMPTY_LIST);
+        assertThat(aList, is(Collections.EMPTY_LIST));
+    }
+
+    private List<String> aMethodReturningNonNullList(){
+        return List.of("item1", "item2");
+    }
+
+    @Test
+    public void givenObject_whenRequireNonNullElse_thenObject(){
+        List<String> aList = Objects.<List>requireNonNullElse(
+                aMethodReturningNonNullList(), Collections.EMPTY_LIST);
+        assertThat(aList, is(List.of("item1", "item2")));
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void givenNull_whenRequireNonNullElse_thenException(){
+        Objects.<List>requireNonNullElse(null, null);
+    }
+
+    @Test
+    public void givenObject_whenRequireNonNullElseGet_thenObject(){
+        List<String> aList = Objects.<List>requireNonNullElseGet(null, List::of);
+        assertThat(aList, is(List.of()));
+    }
+
+    @Test
+    public void givenNumber_whenInvokeCheckIndex_thenNumber(){
+        int length = 5;
+        assertThat(Objects.checkIndex(4, length), is(4));
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void givenOutOfRangeNumber_whenInvokeCheckIndex_thenException(){
+        int length = 5;
+        Objects.checkIndex(5, length);
+    }
+
+
+    @Test
+    public void givenSubRange_whenCheckFromToIndex_thenNumber(){
+        int length = 6;
+        assertThat(Objects.checkFromToIndex(2,length,length), is(2));
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void givenInvalidSubRange_whenCheckFromToIndex_thenException(){
+        int length = 6;
+        Objects.checkFromToIndex(2,7,length);
+    }
+
+
+    @Test
+    public void givenSubRange_whenCheckFromIndexSize_thenNumber(){
+        int length = 6;
+        assertThat(Objects.checkFromIndexSize(2,3,length), is(2));
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void givenInvalidSubRange_whenCheckFromIndexSize_thenException(){
+        int length = 6;
+        Objects.checkFromIndexSize(2, 6, length);
+    }
+
+
+}

core-java/hashcode/pom.xml

@@ -1,39 +0,0 @@
-<?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>
-    <groupId>com.baeldung.hashcode</groupId>
-    <artifactId>hashcode</artifactId>
-    <version>1.0</version>
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
-    <dependencies>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>4.12</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-api</artifactId>
-            <version>1.7.25</version>
-        </dependency>
-        <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-simple</artifactId>
-            <version>1.7.25</version>
-        </dependency>
-    </dependencies>
-</project>

core-java/hashcode/src/main/java/com/baeldung/application/Application.java

@@ -1,23 +0,0 @@
-package com.baeldung.application;
-
-import com.baeldung.entities.User;
-import java.util.HashMap;
-import java.util.Map;
-
-public class Application {
-
-    public static void main(String[] args) {
-        Map<User, User> users = new HashMap<>();
-        User user1 = new User(1L, "John", "[email protected]");
-        User user2 = new User(2L, "Jennifer", "[email protected]");
-        User user3 = new User(3L, "Mary", "[email protected]");
-
-        users.put(user1, user1);
-        users.put(user2, user2);
-        users.put(user3, user3);
-
-        if (users.containsKey(user1)) {
-            System.out.print("User found in the collection");
-        }
-    }
-}

core-java/hashcode/src/main/java/com/baeldung/entities/User.java

@@ -1,38 +0,0 @@
-package com.baeldung.entities;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-public class User {
-
-    private final Logger logger = LoggerFactory.getLogger(User.class);
-    private long id;
-    private String name;
-    private String email;
-
-    public User(long id, String name, String email) {
-        this.id = id;
-        this.name = name;
-        this.email = email;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null) return false;
-        if (this.getClass() != o.getClass()) return false;
-        User user = (User) o;
-        return id != user.id && (!name.equals(user.name) && !email.equals(user.email));
-    }
-    	
-    @Override
-    public int hashCode() {
-        int hash = 7;
-        hash = 31 * hash + (int) id;
-        hash = 31 * hash + (name == null ? 0 : name.hashCode());
-        hash = 31 * hash + (email == null ? 0 : email.hashCode());
-        logger.info("hashCode() method called - Computed hash: " + hash);
-        return hash;
-    }
-    // getters and setters here
-}

core-java/hashcode/src/test/java/com/baeldung/application/ApplicationTest.java

@@ -1,30 +0,0 @@
-package com.baeldung.application;
-
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import java.io.ByteArrayOutputStream;
-import java.io.PrintStream;
-import static org.junit.Assert.assertEquals;
-
-public class ApplicationTest {
-
-    private ByteArrayOutputStream outContent;
-
-    @Before
-    public void setUpPrintStreamInstance() throws Exception {
-        this.outContent = new ByteArrayOutputStream();
-        System.setOut(new PrintStream(outContent));
-    }
-
-    @After
-    public void tearDownByteArrayOutputStream() throws Exception {
-        outContent = null;
-    }
-
-    @Test
-    public void main_NoInputState_TextPrintedToConsole() throws Exception {
-        Application.main(new String[]{});
-        assertEquals("User found in the collection", outContent.toString());
-    }
-}

core-java/hashcode/src/test/java/com/baeldung/entities/UserTest.java

@@ -1,34 +0,0 @@
-package com.baeldung.entities;
-
-import org.junit.After;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-
-public class UserTest {
-
-    private User user;
-    private User comparisonUser;
-
-    @Before
-    public void setUpUserInstances() {
-        this.user = new User(1L, "test", "[email protected]");
-        this.comparisonUser = this.user;
-    }
-
-    @After
-    public void tearDownUserInstances() {
-        user = null;
-        comparisonUser = null;
-    }
-
-    @Test
-    public void equals_EqualUserInstance_TrueAssertion(){
-        Assert.assertTrue(user.equals(comparisonUser));
-    }
-
-    @Test
-    public void hashCode_UserHash_TrueAssertion() {
-        Assert.assertEquals(1792276941, user.hashCode());
-    }
-}