Merge remote-tracking branch 'upstream/master' into BAEL_4302

2020-07-14 19:03:16 +00:00
parent c5c128033d 7c344b57c3
commit d52f676eda
325 changed files with 21314 additions and 475 deletions
@@ -27,6 +27,11 @@
            <version>${assertj.version}</version>
            <scope>test</scope>
        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>3.10</version>
+        </dependency>
    </dependencies>

    <properties>
@@ -0,0 +1,47 @@
+package com.baeldung.collections.iterators;
+
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import com.google.common.primitives.Ints;
+import org.apache.commons.lang3.ArrayUtils;
+
+public class ConvertPrimitivesArrayToList {
+
+    public static void failConvert() {
+        int[] input = new int[]{1,2,3,4};
+        // List<Integer> inputAsList = Arrays.asList(input);
+    }
+
+    public static List<Integer> iterateConvert(int[] input) {
+        List<Integer> output = new ArrayList<Integer>();
+        for (int value : input) {
+            output.add(value);
+        }
+        return output;
+    }
+
+    public static List<Integer> streamConvert(int[] input) {
+        List<Integer> output = Arrays.stream(input).boxed().collect(Collectors.toList());
+        return output;
+    }
+
+    public static List<Integer> streamConvertIntStream(int[] input) {
+        List<Integer> output = IntStream.of(input).boxed().collect(Collectors.toList());
+        return output;
+    }
+
+    public static List<Integer> guavaConvert(int[] input) {
+        List<Integer> output = Ints.asList(input);
+        return output;
+    }
+
+    public static List<Integer> apacheCommonConvert(int[] input) {
+        Integer[] outputBoxed = ArrayUtils.toObject(input);
+        List<Integer> output = Arrays.asList(outputBoxed);
+        return output;
+    }
+
+}
@@ -0,0 +1,38 @@
+package com.baeldung.collections.iterators;
+
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.stream.Collectors;
+import com.google.common.primitives.Ints;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class ConvertPrimitivesArrayToListUnitTest {
+
+    @Test
+    public void givenArrayWithPrimitives_whenIterativeConvert_thenArrayGetsConverted() {
+        assertEquals(Arrays.asList(1,2,3,4), ConvertPrimitivesArrayToList.iterateConvert(new int[]{1,2,3,4}));
+    }
+
+    @Test
+    public void givenArrayWithPrimitives_whenStreamConvert_thenArrayGetsConverted() {
+        assertEquals(Arrays.asList(1,2,3,4), ConvertPrimitivesArrayToList.streamConvert(new int[]{1,2,3,4}));
+    }
+
+    @Test
+    public void givenArrayWithPrimitives_whenIntStreamConvert_thenArrayGetsConverted() {
+        assertEquals(Arrays.asList(1,2,3,4), ConvertPrimitivesArrayToList.streamConvertIntStream(new int[]{1,2,3,4}));
+    }
+
+    @Test
+    public void givenArrayWithPrimitives_whenGuavaConvert_thenArrayGetsConverted() {
+        assertEquals(Arrays.asList(1,2,3,4), ConvertPrimitivesArrayToList.guavaConvert(new int[]{1,2,3,4}));
+    }
+
+    @Test
+    public void givenArrayWithPrimitives_whenApacheCommonConvert_thenArrayGetsConverted() {
+        assertEquals(Arrays.asList(1,2,3,4), ConvertPrimitivesArrayToList.apacheCommonConvert(new int[]{1,2,3,4}));
+    }
+}
@@ -0,0 +1,10 @@
+package com.baeldung.concurrent.localvariables;
+
+public class LocalAndLambda {
+    public static void main(String... args) {
+        String text = "";
+        // Un-commenting the next line will break compilation, because text is no longer effectively final
+        // text = "675";
+        new Thread(() -> System.out.println(text)).start();
+    }
+}
@@ -0,0 +1,20 @@
+package com.baeldung.concurrent.localvariables;
+
+import java.security.SecureRandom;
+
+public class LocalVariables implements Runnable {
+    private int field;
+
+    public static void main(String... args) {
+        LocalVariables target = new LocalVariables();
+        new Thread(target).start();
+        new Thread(target).start();
+    }
+
+    @Override
+    public void run() {
+        field = new SecureRandom().nextInt();
+        int local = new SecureRandom().nextInt();
+        System.out.println(field + " - " + local);
+    }
+}
@@ -1,3 +1,5 @@
 ### Relevant Articles:

 - [Introduction to Lock Striping](https://www.baeldung.com/java-lock-stripping)
+- [Guide to the Java TransferQueue](http://www.baeldung.com/java-transfer-queue)
+- [[<-- Prev]](/core-java-modules/core-java-concurrency-collections)
@@ -3,9 +3,16 @@
    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.concurrent.lock</groupId>
    <artifactId>core-java-concurrency-collections-2</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-concurrency-collections-2</name>
+    <packaging>jar</packaging>
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../</relativePath>
+    </parent>

    <dependencies>
        <dependency>
@@ -30,19 +37,6 @@
            <scope>test</scope>
        </dependency>
    </dependencies>
-    <build>
-        <sourceDirectory>src</sourceDirectory>
-        <plugins>
-            <plugin>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.8.0</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>

    <properties>
        <jmh.version>1.21</jmh.version>
@@ -19,7 +19,7 @@ import org.junit.FixMethodOrder;
 import org.junit.Test;

@FixMethodOrder
-public class TestConcurrentLinkedQueue {
+public class ConcurrentLinkedQueueUnitTest {

    @Test
    public void givenThereIsExistingCollection_WhenAddedIntoQueue_ThenShouldContainElements() {
@@ -18,7 +18,7 @@ import org.junit.FixMethodOrder;
 import org.junit.Test;

@FixMethodOrder
-public class TestLinkedBlockingQueue {
+public class LinkedBlockingQueueUnitTest {

    @Test
    public void givenThereIsExistingCollection_WhenAddedIntoQueue_ThenShouldContainElements() {
@@ -4,7 +4,11 @@ import org.junit.FixMethodOrder;
 import org.junit.Test;
 import org.junit.runners.MethodSorters;

-import java.util.concurrent.*;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedTransferQueue;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TransferQueue;

 import static junit.framework.TestCase.assertEquals;

@@ -10,7 +10,7 @@ This module contains articles about concurrent Java collections
 - [Custom Thread Pools In Java 8 Parallel Streams](http://www.baeldung.com/java-8-parallel-streams-custom-threadpool)
 - [Guide to DelayQueue](http://www.baeldung.com/java-delay-queue)
 - [A Guide to Java SynchronousQueue](http://www.baeldung.com/java-synchronous-queue)
- [Guide to the Java TransferQueue](http://www.baeldung.com/java-transfer-queue)
 - [Guide to the ConcurrentSkipListMap](http://www.baeldung.com/java-concurrent-skip-list-map)
 - [Guide to CopyOnWriteArrayList](http://www.baeldung.com/java-copy-on-write-arraylist)
 - [LinkedBlockingQueue vs ConcurrentLinkedQueue](https://www.baeldung.com/java-queue-linkedblocking-concurrentlinked)
+- [[Next -->]](/core-java-modules/core-java-concurrency-collections-2)
@@ -33,7 +33,6 @@
    <url>http://maven.apache.org</url>

    <properties>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <commons.lang3.version>3.10</commons.lang3.version>
        <!-- testing -->
        <assertj-core.version>3.10.0</assertj-core.version>
@@ -6,4 +6,6 @@ This module contains articles about core Java input/output(IO) conversions.
 - [Java InputStream to String](https://www.baeldung.com/convert-input-stream-to-string)
 - [Java – Write an InputStream to a File](https://www.baeldung.com/convert-input-stream-to-a-file)
 - [Converting a BufferedReader to a JSONObject](https://www.baeldung.com/java-bufferedreader-to-jsonobject)
+- [Reading a CSV File into an Array](https://www.baeldung.com/java-csv-file-array)
+- [How to Write to a CSV File in Java](https://www.baeldung.com/java-csv)
 - More articles: [[<-- prev]](/core-java-modules/core-java-io-conversions)
@@ -26,6 +26,12 @@
            <artifactId>json</artifactId>
            <version>${json.version}</version>
        </dependency>
+        <dependency>
+            <groupId>com.opencsv</groupId>
+            <artifactId>opencsv</artifactId>
+            <version>${opencsv.version}</version>
+            <scope>test</scope>
+        </dependency>
    </dependencies>

    <build>
@@ -40,6 +46,7 @@

    <properties>
        <json.version>20200518</json.version>
+        <opencsv.version>4.1</opencsv.version>
    </properties>

 </project>
@@ -1,20 +1,11 @@
 package com.baeldung.csv;

-import java.io.BufferedReader;
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.FileReader;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import java.util.Scanner;
-
+import com.opencsv.CSVReader;
 import org.junit.Assert;
 import org.junit.Test;

-import com.opencsv.CSVReader;
+import java.io.*;
+import java.util.*;

 public class ReadCSVInArrayUnitTest {
    public static final String COMMA_DELIMITER = ",";
@@ -1,7 +1,9 @@
 package com.baeldung.csv;

-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import org.junit.Before;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;

 import java.io.File;
 import java.io.FileNotFoundException;
@@ -10,10 +12,8 @@ import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.List;

-import org.junit.Before;
-import org.junit.Test;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;

 public class WriteCsvFileExampleUnitTest {
    private static final Logger LOG = LoggerFactory.getLogger(WriteCsvFileExampleUnitTest.class);
@@ -8,10 +8,9 @@ This module contains articles about core Java input and output (IO)
 - [Java – Directory Size](https://www.baeldung.com/java-folder-size)
 - [File Size in Java](https://www.baeldung.com/java-file-size)
 - [Zipping and Unzipping in Java](https://www.baeldung.com/java-compress-and-uncompress)
- [Reading a CSV File into an Array](https://www.baeldung.com/java-csv-file-array)
 - [How to Get the File Extension of a File in Java](https://www.baeldung.com/java-file-extension)
 - [Getting a File’s Mime Type in Java](https://www.baeldung.com/java-file-mime-type)
- [How to Write to a CSV File in Java](https://www.baeldung.com/java-csv)
 - [How to Avoid the Java FileNotFoundException When Loading Resources](https://www.baeldung.com/java-classpath-resource-cannot-be-opened)
 - [Create a Directory in Java](https://www.baeldung.com/java-create-directory)
+- [Java – Rename or Move a File](https://www.baeldung.com/java-how-to-rename-or-move-a-file)
 - [[More -->]](/core-java-modules/core-java-io-2)
@@ -29,12 +29,6 @@
            <version>${hsqldb.version}</version>
            <scope>runtime</scope>
        </dependency>
-        <dependency>
-            <groupId>com.opencsv</groupId>
-            <artifactId>opencsv</artifactId>
-            <version>${opencsv.version}</version>
-            <scope>test</scope>
-        </dependency>
        <!-- Mime Type Resolution Libraries -->
        <dependency>
            <groupId>org.apache.tika</groupId>
@@ -142,8 +136,6 @@
    </profiles>

    <properties>
-        <!-- util -->
-        <opencsv.version>4.1</opencsv.version>
        <!-- testing -->
        <assertj.version>3.6.1</assertj.version>
        <!-- maven plugins -->
@@ -0,0 +1,64 @@
+package com.baeldung.rename;
+
+import org.apache.commons.io.FileUtils;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.FileSystemException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+public class RenameFileUnitTest {
+
+    private final String FILE_TO_MOVE = "src/test/resources/originalFileToMove.txt";
+    private final String TARGET_FILE = "src/test/resources/targetFileToMove.txt";
+
+    @BeforeEach
+    public void createFileToMove() throws IOException {
+        File fileToMove = new File(FILE_TO_MOVE);
+        fileToMove.createNewFile();
+    }
+
+    @AfterEach
+    public void cleanUpFiles() {
+        File targetFile = new File(TARGET_FILE);
+        targetFile.delete();
+    }
+
+    @Test
+    public void givenUsingNio_whenMovingFile_thenCorrect() throws IOException {
+        Path fileToMovePath = Paths.get(FILE_TO_MOVE);
+        Path targetPath = Paths.get(TARGET_FILE);
+        Files.move(fileToMovePath, targetPath);
+    }
+
+    @Test
+    public void givenUsingFileClass_whenMovingFile_thenCorrect() throws IOException {
+        File fileToMove = new File(FILE_TO_MOVE);
+        boolean isMoved = fileToMove.renameTo(new File(TARGET_FILE));
+        if (!isMoved) {
+            throw new FileSystemException(TARGET_FILE);
+        }
+    }
+
+    @Test
+    public void givenUsingGuava_whenMovingFile_thenCorrect()
+            throws IOException {
+        File fileToMove = new File(FILE_TO_MOVE);
+        File targetFile = new File(TARGET_FILE);
+
+        com.google.common.io.Files.move(fileToMove, targetFile);
+    }
+
+    @Test
+    public void givenUsingApache_whenMovingFile_thenCorrect() throws IOException {
+        FileUtils.moveFile(
+                FileUtils.getFile(FILE_TO_MOVE),
+                FileUtils.getFile(TARGET_FILE));
+    }
+
+}
@@ -2,4 +2,10 @@

 This module contains articles about working with the Java Virtual Machine (JVM).

-### Relevant Articles: 
+### Relevant Articles: 
+
+- [Memory Layout of Objects in Java](https://www.baeldung.com/java-memory-layout)
+- [Measuring Object Sizes in the JVM](https://www.baeldung.com/jvm-measuring-object-sizes)
+- [Adding Shutdown Hooks for JVM Applications](https://www.baeldung.com/jvm-shutdown-hooks)
+- [boolean and boolean[] Memory Layout in the JVM](https://www.baeldung.com/jvm-boolean-memory-layout)
+- More articles: [[<-- prev]](/core-java-modules/core-java-jvm)
@@ -0,0 +1,24 @@
+package com.baeldung.memaddress;
+
+import org.junit.Test;
+import org.openjdk.jol.vm.VM;
+
+public class MemoryAddressUnitTest {
+
+    @Test
+    public void printTheMemoryAddress() {
+        String answer = "42";
+
+        System.out.println("The memory address is " + VM.current().addressOf(answer));
+    }
+
+    @Test
+    public void identityHashCodeAndMemoryAddress() {
+        Object obj = new Object();
+
+        System.out.println("Memory address: " + VM.current().addressOf(obj));
+        System.out.println("hashCode: " + obj.hashCode());
+        System.out.println("hashCode: " + System.identityHashCode(obj));
+        System.out.println("toString: " + obj);
+    }
+}
@@ -0,0 +1,10 @@
+package com.baeldung.objectsize;
+
+public class Course {
+
+    private String name;
+
+    public Course(String name) {
+        this.name = name;
+    }
+}
@@ -0,0 +1,11 @@
+package com.baeldung.objectsize;
+
+public class InstrumentedSize {
+
+    public static void main(String[] args) {
+        String ds = "Data Structures";
+        Course course = new Course(ds);
+
+        System.out.println(ObjectSizeCalculator.sizeOf(course));
+    }
+}
@@ -0,0 +1 @@
+Premain-Class: com.baeldung.objectsize.ObjectSizeCalculator
--- a/Show More
+++ b/Show More
				`@@ -0,0 +1 @@`
				`Premain-Class: com.baeldung.objectsize.ObjectSizeCalculator`