Merge branch 'master' of https://github.com/eugenp/tutorials

algorithms-miscellaneous-3/README.md

@@ -1,4 +1,4 @@
-## Relevant articles:
+## Relevant Articles:
 
 - [Java Two Pointer Technique](https://www.baeldung.com/java-two-pointer-technique)
 - [Implementing Simple State Machines with Java Enums](https://www.baeldung.com/java-enum-simple-state-machine)

core-groovy-2/src/main/groovy/com/baeldung/metaprogramming/Employee.groovy

@@ -0,0 +1,45 @@
+package com.baeldung.metaprogramming
+
+import groovy.transform.AutoClone
+import groovy.transform.Canonical
+import groovy.transform.EqualsAndHashCode
+import groovy.transform.ToString
+import groovy.transform.TupleConstructor
+import groovy.util.logging.*
+
+@Canonical
+@TupleConstructor
+@EqualsAndHashCode
+@ToString(includePackage=false, excludes=['id'])
+@Log 
+@AutoClone
+class Employee {
+
+    long id
+    String firstName
+    String lastName
+    int age
+
+    //method to catch missing property's getter
+    def propertyMissing(String propertyName) {
+        log.info "$propertyName is not available"
+        "property '$propertyName' is not available"
+    }
+
+    //method to catch missing property's setter
+    def propertyMissing(String propertyName, propertyValue) {
+        println "property '$propertyName' is not available"
+        log.info "$propertyName is not available"
+        "property '$propertyName' is not available"
+    }
+
+    def methodMissing(String methodName, def methodArgs) {
+        log.info "$methodName is not defined"
+        "method '$methodName' is not defined"
+    }
+    
+    def logEmp() {
+        log.info "Employee: $lastName, $firstName is of $age years age"
+    }
+
+}

core-groovy-2/src/main/groovy/com/baeldung/metaprogramming/extension/BasicExtensions.groovy

@@ -0,0 +1,30 @@
+package com.baeldung.metaprogramming.extension
+
+import com.baeldung.metaprogramming.Employee
+
+class BasicExtensions {
+    
+    static int getYearOfBirth(Employee self) {
+        return (new Date().getYear() + 1900) - self.age;
+    }
+    
+    static String capitalize(String self) {
+        return self.substring(0, 1).toUpperCase() + self.substring(1)
+    }
+
+    static void printCounter(Integer self) {
+        while (self>0) {
+            println self
+            self--
+        }
+    }
+    
+    static Long square(Long self) {
+        return self*self
+    }
+    
+    static BigDecimal cube(BigDecimal self) {
+        return self*self*self
+    }
+    
+}

core-groovy-2/src/main/groovy/com/baeldung/metaprogramming/extension/StaticEmployeeExtension.groovy

@@ -0,0 +1,10 @@
+package com.baeldung.metaprogramming.extension
+
+import com.baeldung.metaprogramming.Employee
+
+class StaticEmployeeExtension {
+    
+    static Employee getDefaultObj(Employee self) {
+        return new Employee(firstName: "firstName", lastName: "lastName", age: 20)
+    }
+}

core-groovy-2/src/main/resources/META-INF/services/org.codehaus.groovy.runtime.ExtensionModule

@@ -0,0 +1,4 @@
+moduleName=core-groovy-2
+moduleVersion=1.0-SNAPSHOT
+extensionClasses=com.baeldung.metaprogramming.extension.BasicExtensions
+staticExtensionClasses=com.baeldung.metaprogramming.extension.StaticEmployeeExtension

core-groovy-2/src/test/groovy/com/baeldung/metaprogramming/MetaprogrammingUnitTest.groovy

@@ -0,0 +1,118 @@
+package com.baeldung.metaprogramming
+
+import groovy.time.TimeCategory
+
+class MetaprogrammingUnitTest extends GroovyTestCase {
+
+    Employee emp = new Employee(firstName: "Norman", lastName: "Lewis")
+
+    void testPropertyMissing() {
+        assert emp.address == "property 'address' is not available"
+    }
+
+    void testMethodMissing() {
+        Employee emp = new Employee()
+        try {
+            emp.getFullName()
+        } catch(MissingMethodException e) {
+            println "method is not defined"
+        }
+        assert emp.getFullName() == "method 'getFullName' is not defined"
+    }
+
+    void testMetaClassProperty() {
+        Employee.metaClass.address = ""
+        emp = new Employee(firstName: "Norman", lastName: "Lewis", address: "US")
+        assert emp.address == "US"
+    }
+
+    void testMetaClassMethod() {
+        emp.metaClass.getFullName = {
+            "$lastName, $firstName"
+        }
+        assert emp.getFullName() == "Lewis, Norman"
+    }
+
+    void testMetaClassConstructor() {
+        try {
+            Employee emp = new Employee("Norman")
+        } catch(GroovyRuntimeException e) {
+            assert e.message == "Could not find matching constructor for: com.baeldung.metaprogramming.Employee(String)"
+        }
+
+        Employee.metaClass.constructor = { String firstName ->
+            new Employee(firstName: firstName)
+        }
+
+        Employee norman = new Employee("Norman")
+        assert norman.firstName == "Norman"
+        assert norman.lastName == null
+    }
+
+    void testJavaMetaClass() {
+        String.metaClass.capitalize = { String str ->
+            str.substring(0, 1).toUpperCase() + str.substring(1);
+        }
+        assert "norman".capitalize() == "Norman"
+    }
+
+    void testEmployeeExtension() {
+        Employee emp = new Employee(age: 28)
+        assert emp.getYearOfBirth() == 1991
+    }
+
+    void testJavaClassesExtensions() {
+        5.printCounter()
+
+        assert 40l.square() == 1600l
+
+        assert (2.98).cube() == 26.463592
+    }
+
+    void testStaticEmployeeExtension() {
+        assert Employee.getDefaultObj().firstName == "firstName"
+        assert Employee.getDefaultObj().lastName == "lastName"
+        assert Employee.getDefaultObj().age == 20
+    }
+
+    void testToStringAnnotation() {
+        Employee employee = new Employee()
+        employee.id = 1
+        employee.firstName = "norman"
+        employee.lastName = "lewis"
+        employee.age = 28
+
+        assert employee.toString() == "Employee(norman, lewis, 28)"
+    }
+
+    void testTupleConstructorAnnotation() {
+        Employee norman = new Employee(1, "norman", "lewis", 28)
+        assert norman.toString() == "Employee(norman, lewis, 28)"
+
+        Employee snape = new Employee(2, "snape")
+        assert snape.toString() == "Employee(snape, null, 0)"
+
+    }
+    
+    void testEqualsAndHashCodeAnnotation() {
+        Employee norman = new Employee(1, "norman", "lewis", 28)
+        Employee normanCopy = new Employee(1, "norman", "lewis", 28)
+        assert norman.equals(normanCopy)
+        assert norman.hashCode() == normanCopy.hashCode()
+    }
+    
+    void testAutoCloneAnnotation() {
+        try {
+            Employee norman = new Employee(1, "norman", "lewis", 28)
+            def normanCopy = norman.clone()
+            assert norman == normanCopy
+        } catch(CloneNotSupportedException e) {
+            e.printStackTrace()
+        }
+    }
+
+    void testLoggingAnnotation() {
+        Employee employee = new Employee(1, "Norman", "Lewis", 28)
+        employee.logEmp()
+    }
+}

core-java-modules/core-java-8-2/README.md

@@ -7,3 +7,4 @@
 - [How to Delay Code Execution in Java](https://www.baeldung.com/java-delay-code-execution)
 - [Run JAR Application With Command Line Arguments](https://www.baeldung.com/java-run-jar-with-arguments)
 - [Java 8 Stream skip() vs limit()](https://www.baeldung.com/java-stream-skip-vs-limit)
+- [Guide to Java BiFunction Interface](https://www.baeldung.com/java-bifunction-interface)

core-java-modules/core-java-arrays/README.md

@@ -7,7 +7,7 @@
 - [Check if a Java Array Contains a Value](http://www.baeldung.com/java-array-contains-value)
 - [Initializing Arrays in Java](http://www.baeldung.com/java-initialize-array)
 - [Guide to the java.util.Arrays Class](http://www.baeldung.com/java-util-arrays)
-- [Jagged Arrays In Java](http://www.baeldung.com/java-jagged-arrays)
+- [Multi-Dimensional Arrays In Java](http://www.baeldung.com/java-jagged-arrays)
 - [Find Sum and Average in a Java Array](http://www.baeldung.com/java-array-sum-average)
 - [Arrays in Java: A Reference Guide](https://www.baeldung.com/java-arrays-guide)
 - [How to Invert an Array in Java](http://www.baeldung.com/java-invert-array)
@@ -16,3 +16,4 @@
 - [Sorting Arrays in Java](https://www.baeldung.com/java-sorting-arrays)
 - [Convert a Float to a Byte Array in Java](https://www.baeldung.com/java-convert-float-to-byte-array)
 - [Converting Between Stream and Array in Java](https://www.baeldung.com/java-stream-to-array)
+- [Removing an Element from an Array in Java](https://www.baeldung.com/java-array-remove-element)

core-java-modules/core-java-jpms/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles
+
+- [Design Strategies for Decoupling Java Modules](https://www.baeldung.com/java-modules-decoupling-design-strategies)

core-java-modules/core-java-lang-operators/pom.xml

@@ -0,0 +1,43 @@
+<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>core-java-lang-operators</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-lang-operators</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-lang-operators</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+        <!-- testing -->
+        <assertj-core.version>3.10.0</assertj-core.version>
+    </properties>
+
+</project>

core-java-modules/core-java-lang-operators/src/test/java/com/baeldung/incrementdecrementunaryoperators/IncrementDecrementUnaryOperatorUnitTest.java

@@ -1,6 +1,7 @@
-package com.baeldung.incrementdecrementunaryoperator;
+package com.baeldung.incrementdecrementunaryoperators;
 
 import static org.assertj.core.api.Assertions.assertThat;
+
 import org.junit.Test;
 
 public class IncrementDecrementUnaryOperatorUnitTest {

core-java-modules/core-java-lang-syntax/README.md

@@ -18,3 +18,4 @@
 - [The Modulo Operator in Java](https://www.baeldung.com/modulo-java)
 - [Ternary Operator In Java](https://www.baeldung.com/java-ternary-operator)
 - [Java instanceof Operator](https://www.baeldung.com/java-instanceof)
+- [Breaking Out of Nested Loops](https://www.baeldung.com/java-breaking-out-nested-loop)

core-java-modules/core-java-nio/README.md

@@ -1,3 +1,3 @@
-## Relevant articles:
+## Relevant Articles:
 
-- [Determine File Creating Date in Java](https://www.baeldung.com/java-file-creation-date)
+- [Determine File Creation Date in Java](https://www.baeldung.com/java-file-creation-date)

core-java-modules/core-java-security/README.md

@@ -10,3 +10,4 @@
 - [SSL Handshake Failures](https://www.baeldung.com/java-ssl-handshake-failures)
 - [SHA-256 and SHA3-256 Hashing in Java](https://www.baeldung.com/sha-256-hashing-java)
 - [Enabling TLS v1.2 in Java 7](https://www.baeldung.com/java-7-tls-v12)
+- [The Java SecureRandom Class](https://www.baeldung.com/java-secure-random)

core-java-modules/pom.xml

@@ -17,6 +17,7 @@
         <module>pre-jpms</module>
         <module>core-java-exceptions</module>
         <module>core-java-optional</module>
+        <module>core-java-lang-operators</module>
         <module>core-java-networking-2</module>
     </modules>
     

data-structures/README.md

@@ -1,4 +1,5 @@
 ## Relevant articles:
 
-[The Trie Data Structure in Java](https://www.baeldung.com/trie-java)
-[Implementing a Binary Tree in Java](https://www.baeldung.com/java-binary-tree)
+- [The Trie Data Structure in Java](https://www.baeldung.com/trie-java)
+- [Implementing a Binary Tree in Java](https://www.baeldung.com/java-binary-tree)
+- [Depth First Search in Java](https://www.baeldung.com/java-depth-first-search)