[BAEL-15998] - Move articles out of core-java-io part 1

core-java-modules/core-java-nio-2/src/test/java/com/baeldung/mappedbytebuffer/MappedByteBufferUnitTest.java

@@ -0,0 +1,68 @@
+package com.baeldung.mappedbytebuffer;
+
+import org.junit.Test;
+
+import java.nio.CharBuffer;
+import java.nio.MappedByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardOpenOption;
+import java.util.EnumSet;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class MappedByteBufferUnitTest {
+
+    @Test
+    public void givenFileChannel_whenReadToTheMappedByteBuffer_thenShouldSuccess() throws Exception {
+        // given
+        CharBuffer charBuffer = null;
+        Path pathToRead = getFileURIFromResources("fileToRead.txt");
+
+        // when
+        try (FileChannel fileChannel = (FileChannel) Files.newByteChannel(pathToRead, EnumSet.of(StandardOpenOption.READ))) {
+            MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_ONLY, 0, fileChannel.size());
+
+            if (mappedByteBuffer != null) {
+                charBuffer = Charset.forName("UTF-8").decode(mappedByteBuffer);
+            }
+        }
+
+        // then
+        assertNotNull(charBuffer);
+        assertEquals(charBuffer.toString(), "This is a content of the file");
+    }
+
+    @Test
+    public void givenPath_whenWriteToItUsingMappedByteBuffer_thenShouldSuccessfullyWrite() throws Exception {
+        // given
+        final CharBuffer charBuffer = CharBuffer.wrap("This will be written to the file");
+        final Path pathToWrite = getFileURIFromResources("fileToWriteTo.txt");
+
+        // when
+        try (FileChannel fileChannel = (FileChannel) Files.newByteChannel(pathToWrite, EnumSet.of(StandardOpenOption.READ, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING))) {
+            MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, charBuffer.length());
+
+            if (mappedByteBuffer != null) {
+                mappedByteBuffer.put(Charset.forName("utf-8").encode(charBuffer));
+            }
+        }
+
+        // then
+        final List<String> fileContent = Files.readAllLines(pathToWrite);
+        assertEquals(fileContent.get(0), "This will be written to the file");
+
+    }
+
+    //
+
+    private final Path getFileURIFromResources(String fileName) throws Exception {
+        final ClassLoader classLoader = getClass().getClassLoader();
+        return Paths.get(classLoader.getResource(fileName).toURI());
+    }
+}

core-java-modules/core-java-nio-2/src/test/java/com/baeldung/selector/NioEchoLiveTest.java

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+package com.baeldung.selector;
+
+import com.baeldung.selector.EchoClient;
+import com.baeldung.selector.EchoServer;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.junit.Assert.assertEquals;
+
+public class NioEchoLiveTest {
+
+    private Process server;
+    private EchoClient client;
+
+    @Before
+    public void setup() throws IOException, InterruptedException {
+        server = EchoServer.start();
+        client = EchoClient.start();
+    }
+
+    @Test
+    public void givenServerClient_whenServerEchosMessage_thenCorrect() {
+        String resp1 = client.sendMessage("hello");
+        String resp2 = client.sendMessage("world");
+        assertEquals("hello", resp1);
+        assertEquals("world", resp2);
+    }
+
+    @After
+    public void teardown() throws IOException {
+        server.destroy();
+        EchoClient.stop();
+    }
+}

core-java-modules/core-java-nio-2/src/test/java/com/baeldung/symlink/SymLinkExampleManualTest.java

@@ -0,0 +1,36 @@
+package com.baeldung.symlink;
+
+import org.junit.Test;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import static org.junit.Assert.*;
+
+public class SymLinkExampleManualTest {
+
+    @Test
+    public void whenUsingFiles_thenCreateSymbolicLink() throws IOException {
+        SymLinkExample example = new SymLinkExample();
+        Path filePath = example.createTextFile();
+        Path linkPath = Paths.get(".", "symbolic_link.txt");
+        example.createSymbolicLink(linkPath, filePath);
+        assertTrue(Files.isSymbolicLink(linkPath));
+    }
+
+    @Test
+    public void whenUsingFiles_thenCreateHardLink() throws IOException {
+        SymLinkExample example = new SymLinkExample();
+        Path filePath = example.createTextFile();
+        Path linkPath = Paths.get(".", "hard_link.txt");
+        example.createHardLink(linkPath, filePath);
+        assertFalse(Files.isSymbolicLink(linkPath));
+        assertEquals(filePath.toFile()
+            .length(),
+            linkPath.toFile()
+                .length());
+    }
+
+}

core-java-modules/core-java-nio-2/src/test/resources/fileToRead.txt

@@ -0,0 +1 @@
+This is a content of the file