Merge branch 'master' of https://github.com/eugenp/tutorials into task/BAEL-20665

# Conflicts: # core-groovy-2/src/test/groovy/com/baeldung/metaprogramming/MetaprogrammingUnitTest.groovy # core-java-modules/pom.xml # pom.xml
2020-01-12 20:55:19 +05:30
parent 5fe00c432b 0a369c4a16
commit 3cfc8d2163
295 changed files with 4437 additions and 457 deletions
@@ -0,0 +1,52 @@
+<?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>core-java-14</artifactId>
+	<version>1.0.0-SNAPSHOT</version>
+	<name>core-java-14</name>
+	<packaging>jar</packaging>
+	<url>http://maven.apache.org</url>
+
+	<parent>
+		<groupId>com.baeldung</groupId>
+		<artifactId>parent-modules</artifactId>
+		<version>1.0.0-SNAPSHOT</version>
+		<relativePath>../../</relativePath>
+	</parent>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<version>${maven-compiler-plugin.version}</version>
+				<configuration>
+					<source>${maven.compiler.source.version}</source>
+					<target>${maven.compiler.target.version}</target>
+					<compilerArgs>
+						<compilerArg>
+							--enable-preview
+						</compilerArg>
+					</compilerArgs>
+				</configuration>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-surefire-plugin</artifactId>
+				<version>3.0.0-M3</version>
+				<configuration>
+					<argLine>--enable-preview</argLine>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+	<properties>
+		<maven.compiler.source.version>14</maven.compiler.source.version>
+		<maven.compiler.target.version>14</maven.compiler.target.version>
+	</properties>
+
+</project>
@@ -0,0 +1,50 @@
+package com.baeldung.serial;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.ObjectStreamException;
+import java.io.ObjectStreamField;
+import java.io.Serial;
+import java.io.Serializable;
+
+/**
+ * Class showcasing the usage of the Java 14 @Serial annotation.
+ * 
+ * @author Donato Rimenti
+ */
+public class MySerialClass implements Serializable {
+	
+	@Serial
+	private static final ObjectStreamField[] serialPersistentFields = null;
+	
+	@Serial
+	private static final long serialVersionUID = 1;
+
+	@Serial
+	private void writeObject(ObjectOutputStream stream) throws IOException {
+		// ...
+	}
+
+	@Serial
+	private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
+		// ...
+	}
+
+	@Serial
+	private void readObjectNoData() throws ObjectStreamException {
+		// ...
+	}
+
+	@Serial
+	private Object writeReplace() throws ObjectStreamException {
+		// ...
+		return null;
+	}
+
+	@Serial
+	private Object readResolve() throws ObjectStreamException {
+		// ...
+		return null;
+	}
+}
@@ -19,6 +19,16 @@
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>${commons-lang3.version}</version>
+        </dependency>
+		<dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh.version}</version>
        </dependency>
        <!-- test scoped -->
        <dependency>
@@ -37,9 +47,34 @@
                <filtering>true</filtering>
            </resource>
        </resources>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-shade-plugin</artifactId>
+				<version>3.2.0</version>
+				<executions>
+					<execution>
+						<phase>package</phase>
+						<goals>
+							<goal>shade</goal>
+						</goals>
+						<configuration>
+							<finalName>benchmarks</finalName>
+							<transformers>
+								<transformer
+										implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+									<mainClass>org.openjdk.jmh.Main</mainClass>
+								</transformer>
+							</transformers>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
    </build>

    <properties>
+		<jmh.version>1.19</jmh.version>
        <!-- util -->
        <commons-lang3.version>3.9</commons-lang3.version>
        <!-- testing -->
@@ -0,0 +1,72 @@
+package com.baeldung.arraysort;
+
+import java.util.Arrays;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Level;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Warmup;
+import org.openjdk.jmh.infra.Blackhole;
+
+@BenchmarkMode(Mode.AverageTime)
+@Warmup(iterations = 5)
+@Measurement(iterations = 10)
+@Fork(2)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+public class ArraySortingBenchmark {
+
+    @State(Scope.Benchmark)
+    public static class ArrayContainer {
+
+        @Param({ "1000", "10000", "100000", "1000000" })
+        int arraySize;
+
+        // initial unsorted array
+        int[] unsortedArray;
+        
+        //cloned array to sort
+        int[] arrayToSort;
+
+        @Setup(Level.Trial)
+        public void createUnSortedArray() {
+            unsortedArray = new int[arraySize];
+            for (int i = 0; i < arraySize; i++) {
+                unsortedArray[i] = new Random().nextInt(1000);
+            }
+        }
+
+        @Setup(Level.Invocation)
+        public void createUnSortedArrayCopy() {
+            arrayToSort = unsortedArray.clone();
+        }
+
+        int[] getArrayToSort() {
+            return arrayToSort;
+        }
+    }
+
+    @Benchmark
+    public void benchmark_arrays_parallel_sort(ArrayContainer d, Blackhole b) {
+        int[] arr = d.getArrayToSort();
+        Arrays.parallelSort(arr);
+        b.consume(arr);
+    }
+
+    @Benchmark
+    public void benchmark_arrays_sort(ArrayContainer d, Blackhole b) {
+        int[] arr = d.getArrayToSort();
+        Arrays.sort(arr);
+        b.consume(arr);
+    }
+
+}
@@ -24,11 +24,21 @@ public class DuplicatesCounter {
        return resultMap;
    }

-    public static <T> Map<T, Long> countByClassicalLoopWithMapCompute(List<T> inputList) {
+    public static <T> Map<T, Long> countByForEachLoopWithGetOrDefault(List<T> inputList) {
        Map<T, Long> resultMap = new HashMap<>();
-        for (T element : inputList) {
-            resultMap.compute(element, (k, v) -> v == null ? 1 : v + 1);
-        }
+        inputList.forEach(e -> resultMap.put(e, resultMap.getOrDefault(e, 0L) + 1L));
+        return resultMap;
+    }
+
+    public static <T> Map<T, Long> countByForEachLoopWithMapCompute(List<T> inputList) {
+        Map<T, Long> resultMap = new HashMap<>();
+        inputList.forEach(e -> resultMap.compute(e, (k, v) -> v == null ? 1L : v + 1L));
+        return resultMap;
+    }
+
+    public static <T> Map<T, Long> countByForEachLoopWithMapMerge(List<T> inputList) {
+        Map<T, Long> resultMap = new HashMap<>();
+        inputList.forEach(e -> resultMap.merge(e, 1L, Long::sum));
        return resultMap;
    }

@@ -11,7 +11,6 @@ import static org.assertj.core.data.MapEntry.entry;

 class DuplicatesCounterUnitTest {

-
    private static List<String> INPUT_LIST = Lists.list(
        "expect1",
        "expect2", "expect2",
@@ -24,10 +23,21 @@ class DuplicatesCounterUnitTest {
        verifyResult(result);
    }

+    @Test
+    void givenInput_whenCountByForEachLoopWithGetOrDefault_thenGetResultMap() {
+        Map<String, Long> result = DuplicatesCounter.countByForEachLoopWithGetOrDefault(INPUT_LIST);
+        verifyResult(result);
+    }

    @Test
-    void givenInput_whenCountByClassicalLoopWithMapCompute_thenGetResultMap() {
-        Map<String, Long> result = DuplicatesCounter.countByClassicalLoopWithMapCompute(INPUT_LIST);
+    void givenInput_whenCountByForEachLoopWithMapCompute_thenGetResultMap() {
+        Map<String, Long> result = DuplicatesCounter.countByForEachLoopWithMapCompute(INPUT_LIST);
+        verifyResult(result);
+    }
+
+    @Test
+    void givenInput_whenCountByForEachLoopWithMapMerge_thenGetResultMap() {
+        Map<String, Long> result = DuplicatesCounter.countByForEachLoopWithMapMerge(INPUT_LIST);
        verifyResult(result);
    }

@@ -23,6 +23,37 @@
            <version>${assertj.version}</version>
            <scope>test</scope>
        </dependency>
+        
+        <dependency>
+            <groupId>com.jcabi</groupId>
+            <artifactId>jcabi-aspects</artifactId>
+            <version>${jcabi-aspects.version}</version>
+        </dependency>
+        
+        <dependency>
+            <groupId>org.aspectj</groupId>
+            <artifactId>aspectjrt</artifactId>
+            <version>${aspectjrt.version}</version>
+            <scope>runtime</scope>
+        </dependency>
+        
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+        
+        <dependency>
+            <groupId>org.cactoos</groupId>
+            <artifactId>cactoos</artifactId>
+            <version>${cactoos.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.ea.async</groupId>
+            <artifactId>ea-async</artifactId>
+            <version>${ea-async.version}</version>
+        </dependency>
    </dependencies>

    <build>
@@ -36,6 +67,30 @@
                    <target>${maven.compiler.target}</target>
                </configuration>
            </plugin>
+            <plugin>
+                <groupId>com.jcabi</groupId>
+                <artifactId>jcabi-maven-plugin</artifactId>
+                <version>${jcabi-maven-plugin.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>ajc</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.aspectj</groupId>
+                        <artifactId>aspectjtools</artifactId>
+                        <version>${aspectjtools.version}</version>
+                    </dependency>
+                    <dependency>
+                        <groupId>org.aspectj</groupId>
+                        <artifactId>aspectjweaver</artifactId>
+                        <version>${aspectjweaver.version}</version>
+                    </dependency>
+                </dependencies>
+            </plugin>
        </plugins>
        <resources>
            <resource>
@@ -49,6 +104,14 @@
        <assertj.version>3.14.0</assertj.version>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
+        <jcabi-aspects.version>0.22.6</jcabi-aspects.version>
+        <aspectjrt.version>1.9.5</aspectjrt.version>
+        <guava.version>28.2-jre</guava.version>
+        <cactoos.version>0.43</cactoos.version>
+        <ea-async.version>1.2.3</ea-async.version>
+        <jcabi-maven-plugin.version>0.14.1</jcabi-maven-plugin.version>
+        <aspectjtools.version>1.9.1</aspectjtools.version>
+        <aspectjweaver.version>1.9.1</aspectjweaver.version>
    </properties>

 </project>
@@ -0,0 +1,57 @@
+package com.baeldung.async;
+
+import static com.ea.async.Async.await;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+
+import com.ea.async.Async;
+
+public class EAAsyncExample {
+
+    static {
+        Async.init();
+    }
+
+    public static void main(String[] args) throws Exception {
+        usingCompletableFuture();
+        usingAsyncAwait();
+    }
+
+    public static void usingCompletableFuture() throws InterruptedException, ExecutionException, Exception {
+        CompletableFuture<Void> completableFuture = hello()
+            .thenComposeAsync(hello -> mergeWorld(hello))
+            .thenAcceptAsync(helloWorld -> print(helloWorld))
+            .exceptionally( throwable -> {
+                System.out.println(throwable.getCause()); 
+                return null;
+            });
+        completableFuture.get();
+    }
+
+    public static CompletableFuture<String> hello() {
+        CompletableFuture<String> completableFuture = CompletableFuture.supplyAsync(() -> "Hello");
+        return completableFuture;
+    }
+
+    public static CompletableFuture<String> mergeWorld(String s) {
+        CompletableFuture<String> completableFuture = CompletableFuture.supplyAsync(() -> {
+            return s + " World!";
+        });
+        return completableFuture;
+    }
+
+    public static void print(String str) {
+        CompletableFuture.runAsync(() -> System.out.println(str));
+    }
+
+    private static void usingAsyncAwait() {
+        try {
+            String hello = await(hello());
+            String helloWorld = await(mergeWorld(hello));
+            await(CompletableFuture.runAsync(() -> print(helloWorld)));
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+}
@@ -0,0 +1,183 @@
+package com.baeldung.async;
+
+import static com.ea.async.Async.await;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+import com.google.common.util.concurrent.AsyncCallable;
+import com.google.common.util.concurrent.Callables;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.ListeningExecutorService;
+import com.google.common.util.concurrent.MoreExecutors;
+import com.jcabi.aspects.Async;
+import com.jcabi.aspects.Loggable;
+
+public class JavaAsync {
+
+    static {
+        com.ea.async.Async.init();
+    }
+
+    private static final ExecutorService threadpool = Executors.newCachedThreadPool();
+
+    public static void main (String[] args) throws InterruptedException, ExecutionException {
+        int number = 20;
+
+        //Thread Example
+        factorialUsingThread(number).start();
+
+        //FutureTask Example
+        Future<Long> futureTask = factorialUsingFutureTask(number);
+        System.out.println("Factorial of " + number + " is: " + futureTask.get());
+
+        // CompletableFuture Example
+        Future<Long> completableFuture = factorialUsingCompletableFuture(number);
+        System.out.println("Factorial of " + number + " is: " + completableFuture.get());
+
+        // EA Async example
+        System.out.println("Factorial of " + number + " is: " + factorialUsingEAAsync(number));
+
+        // cactoos async example
+        Future<Long> asyncFuture = factorialUsingCactoos(number);
+        System.out.println("Factorial of " + number + " is: " + asyncFuture.get());
+
+        // Guava example
+        ListenableFuture<Long> guavaFuture = factorialUsingGuavaServiceSubmit(number);
+        System.out.println("Factorial of " + number + " is: " + guavaFuture.get());
+
+        ListenableFuture<Long> guavaFutures = factorialUsingGuavaFutures(number);
+        System.out.println("Factorial of " + number + " is: " + guavaFutures.get());
+
+        // @async jcabi-aspect example
+        Future<Long> aspectFuture = factorialUsingJcabiAspect(number);
+        System.out.println("Factorial of " + number + " is: " + aspectFuture.get());
+
+    }
+
+    /**
+     * Finds factorial of a number
+     * @param number
+     * @return
+     */
+    public static long factorial(int number) {
+        long result = 1; 
+        for(int i=number;i>0;i--) {
+            result *= i; 
+        } 
+        return result; 
+    }
+
+    /**
+     * Finds factorial of a number using Thread
+     * @param number
+     * @return
+     */
+    @Loggable
+    public static Thread factorialUsingThread(int number) {
+        Thread newThread = new Thread(() -> {
+            System.out.println("Factorial of " + number + " is: " + factorial(number));
+        });
+
+        return newThread;
+    }
+
+    /**
+     * Finds factorial of a number using FutureTask
+     * @param number
+     * @return
+     */
+    @Loggable
+    public static Future<Long> factorialUsingFutureTask(int number) {
+        Future<Long> futureTask = threadpool.submit(() -> factorial(number)); 
+
+        while (!futureTask.isDone()) { 
+            System.out.println("FutureTask is not finished yet..."); 
+        } 
+
+        return futureTask;
+    }
+
+    /**
+     * Finds factorial of a number using CompletableFuture
+     * @param number
+     * @return
+     */
+    @Loggable
+    public static Future<Long> factorialUsingCompletableFuture(int number) {
+        CompletableFuture<Long> completableFuture = CompletableFuture.supplyAsync(() -> factorial(number));
+        return completableFuture;
+    }
+
+    /**
+     * Finds factorial of a number using EA Async
+     * @param number
+     * @return
+     */
+    @Loggable
+    public static long factorialUsingEAAsync(int number) {
+        CompletableFuture<Long> completableFuture = CompletableFuture.supplyAsync(() -> factorial(number));
+        long result = await(completableFuture);
+        return result;
+    }
+
+    /**
+     * Finds factorial of a number using Async of Cactoos
+     * @param number
+     * @return
+     * @throws InterruptedException
+     * @throws ExecutionException
+     */
+    @Loggable
+    public static Future<Long> factorialUsingCactoos(int number) throws InterruptedException, ExecutionException {
+        org.cactoos.func.Async<Integer, Long> asyncFunction = new org.cactoos.func.Async<Integer, Long>(input -> factorial(input));
+        Future<Long> asyncFuture = asyncFunction.apply(number);
+        return asyncFuture;
+    }
+
+    /**
+     * Finds factorial of a number using Guava's ListeningExecutorService.submit()
+     * @param number
+     * @return
+     */
+    @Loggable
+    public static ListenableFuture<Long> factorialUsingGuavaServiceSubmit(int number) {
+        ListeningExecutorService service = MoreExecutors.listeningDecorator(threadpool);
+        ListenableFuture<Long> factorialFuture = (ListenableFuture<Long>) service.submit(()-> factorial(number));
+        return factorialFuture;
+    }
+
+    /**
+     * Finds factorial of a number using Guava's Futures.submitAsync()
+     * @param number
+     * @return
+     */
+    @Loggable
+    public static ListenableFuture<Long> factorialUsingGuavaFutures(int number) {
+        ListeningExecutorService service = MoreExecutors.listeningDecorator(threadpool);
+        AsyncCallable<Long> asyncCallable = Callables.asAsyncCallable(new Callable<Long>() {
+            public Long call() {
+                return factorial(number);
+            }
+        }, service);
+        return Futures.submitAsync(asyncCallable, service);
+    }
+
+    /**
+     * Finds factorial of a number using @Async of jcabi-aspects
+     * @param number
+     * @return
+     */
+    @Async
+    @Loggable
+    public static Future<Long> factorialUsingJcabiAspect(int number) {
+        Future<Long> factorialFuture = CompletableFuture.supplyAsync(() -> factorial(number));
+        return factorialFuture;
+    }
+
+}
@@ -1,6 +1,5 @@
-## Java Date/time computations Cookbooks and Examples
-
-This module contains articles about date and time computations in Java.
+## Core Date Operations (Part 1)
+This module contains articles about date operations in Java.

 ### Relevant Articles: 
 - [Difference Between Two Dates in Java](http://www.baeldung.com/java-date-difference)
@@ -13,3 +12,4 @@ This module contains articles about date and time computations in Java.
 - [Increment Date in Java](http://www.baeldung.com/java-increment-date)
 - [Add Hours To a Date In Java](http://www.baeldung.com/java-add-hours-date)
 - [Introduction to Joda-Time](http://www.baeldung.com/joda-time)
+- [[Next -->]](/core-java-modules/core-java-date-operations-2)
@@ -2,9 +2,9 @@
 <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>core-java-datetime-computations</artifactId>
+    <artifactId>core-java-date-operations-1</artifactId>
    <version>${project.parent.version}</version>
-    <name>core-java-datetime-computations</name>
+    <name>core-java-date-operations-1</name>
    <packaging>jar</packaging>

    <parent>
@@ -41,7 +41,7 @@
    </dependencies>

    <build>
-        <finalName>core-java-datetime-computations</finalName>
+        <finalName>core-java-date-operations-1</finalName>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
--- a/Show More
+++ b/Show More