Merge pull request #8125 from eugenp/revert-8119-BAEL-3275-2

Revert "BAEL-3275: Using blocking queue for pub-sub"

core-java-modules/core-java-nio/src/test/java/com/baeldung/creationdate/CreationDateResolverUnitTest.java

@@ -0,0 +1,45 @@
+package com.baeldung.creationdate;
+
+import org.junit.Test;
+
+import java.io.File;
+import java.nio.file.Path;
+import java.time.Instant;
+import java.util.Optional;
+
+import static org.junit.Assert.assertTrue;
+
+public class CreationDateResolverUnitTest {
+
+    private final CreationDateResolver creationDateResolver = new CreationDateResolver();
+
+    @Test
+    public void givenFile_whenGettingCreationDateTimeFromBasicAttributes_thenReturnDate() throws Exception {
+
+        final File file = File.createTempFile("createdFile", ".txt");
+        final Path path = file.toPath();
+
+        final Instant response = creationDateResolver.resolveCreationTimeWithBasicAttributes(path);
+
+        assertTrue(Instant
+          .now()
+          .isAfter(response));
+
+    }
+
+    @Test
+    public void givenFile_whenGettingCreationDateTimeFromAttribute_thenReturnDate() throws Exception {
+
+        final File file = File.createTempFile("createdFile", ".txt");
+        final Path path = file.toPath();
+
+        final Optional<Instant> response = creationDateResolver.resolveCreationTimeWithAttribute(path);
+
+        response.ifPresent((value) -> {
+            assertTrue(Instant
+              .now()
+              .isAfter(value));
+        });
+
+    }
+}

core-java-modules/core-java-nio/src/test/java/com/baeldung/file/NumberOfLineFinderUnitTest.java

@@ -0,0 +1,67 @@
+package com.baeldung.file;
+
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingApacheCommonsIO;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingBufferedReader;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingGoogleGuava;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingLineNumberReader;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFileChannel;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFiles;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFilesReadAllLines;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingScanner;
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class NumberOfLineFinderUnitTest {
+    private static final String INPUT_FILE_NAME = "src/main/resources/input.txt";
+    private static final int ACTUAL_LINE_COUNT = 45;
+
+    @Test
+    public void whenUsingBufferedReader_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingBufferedReader(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingLineNumberReader_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingLineNumberReader(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingScanner_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingScanner(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingNIOFiles_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingNIOFiles(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingNIOFilesReadAllLines_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingNIOFilesReadAllLines(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingNIOFileChannel_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingNIOFileChannel(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingApacheCommonsIO_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingApacheCommonsIO(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingGoogleGuava_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingGoogleGuava(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+}

core-java-modules/core-java-nio/src/test/java/com/baeldung/filechannel/FileChannelUnitTest.java

@@ -0,0 +1,165 @@
+package com.baeldung.filechannel;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.io.ByteArrayOutputStream;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.nio.MappedByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.channels.FileLock;
+import java.nio.charset.StandardCharsets;
+
+import org.junit.Test;
+
+public class FileChannelUnitTest {
+
+    @Test
+    public void givenFile_whenReadWithFileChannelUsingRandomAccessFile_thenCorrect() throws IOException {
+
+        try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); 
+            FileChannel channel = reader.getChannel(); 
+            ByteArrayOutputStream out = new ByteArrayOutputStream()) {
+
+            int bufferSize = 1024;
+            if (bufferSize > channel.size()) {
+                bufferSize = (int) channel.size();
+            }
+            ByteBuffer buff = ByteBuffer.allocate(bufferSize);
+
+            while (channel.read(buff) > 0) {
+                out.write(buff.array(), 0, buff.position());
+                buff.clear();
+            }
+
+            String fileContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
+
+            assertEquals("Hello world", fileContent);
+        }
+    }
+
+    @Test
+    public void givenFile_whenReadWithFileChannelUsingFileInputStream_thenCorrect() throws IOException {
+
+        try (ByteArrayOutputStream out = new ByteArrayOutputStream(); 
+            FileInputStream fin = new FileInputStream("src/test/resources/test_read.in"); 
+            FileChannel channel = fin.getChannel()) {
+
+            int bufferSize = 1024;
+            if (bufferSize > channel.size()) {
+                bufferSize = (int) channel.size();
+            }
+            ByteBuffer buff = ByteBuffer.allocate(bufferSize);
+
+            while (channel.read(buff) > 0) {
+                out.write(buff.array(), 0, buff.position());
+                buff.clear();
+            }
+            String fileContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
+
+            assertEquals("Hello world", fileContent);
+        }
+    }
+
+    @Test
+    public void givenFile_whenReadAFileSectionIntoMemoryWithFileChannel_thenCorrect() throws IOException {
+
+        try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); 
+            FileChannel channel = reader.getChannel(); 
+            ByteArrayOutputStream out = new ByteArrayOutputStream()) {
+
+            MappedByteBuffer buff = channel.map(FileChannel.MapMode.READ_ONLY, 6, 5);
+
+            if (buff.hasRemaining()) {
+                byte[] data = new byte[buff.remaining()];
+                buff.get(data);
+                assertEquals("world", new String(data, StandardCharsets.UTF_8));
+            }
+        }
+    }
+
+    @Test
+    public void whenWriteWithFileChannelUsingRandomAccessFile_thenCorrect() throws IOException {
+        String file = "src/test/resources/test_write_using_filechannel.txt";
+        try (RandomAccessFile writer = new RandomAccessFile(file, "rw"); 
+            FileChannel channel = writer.getChannel()) {
+            ByteBuffer buff = ByteBuffer.wrap("Hello world".getBytes(StandardCharsets.UTF_8));
+
+            channel.write(buff);
+
+            // now we verify whether the file was written correctly
+            RandomAccessFile reader = new RandomAccessFile(file, "r");
+            assertEquals("Hello world", reader.readLine());
+            reader.close();
+        }
+    }
+
+    @Test
+    public void givenFile_whenWriteAFileUsingLockAFileSectionWithFileChannel_thenCorrect() throws IOException {
+        try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "rw"); 
+            FileChannel channel = reader.getChannel(); 
+            FileLock fileLock = channel.tryLock(6, 5, Boolean.FALSE);) {
+
+            assertNotNull(fileLock);
+        }
+    }
+
+    @Test
+    public void givenFile_whenReadWithFileChannelGetPosition_thenCorrect() throws IOException {
+
+        try (ByteArrayOutputStream out = new ByteArrayOutputStream(); 
+            RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); 
+            FileChannel channel = reader.getChannel()) {
+
+            int bufferSize = 1024;
+            if (bufferSize > channel.size()) {
+                bufferSize = (int) channel.size();
+            }
+            ByteBuffer buff = ByteBuffer.allocate(bufferSize);
+
+            while (channel.read(buff) > 0) {
+                out.write(buff.array(), 0, buff.position());
+                buff.clear();
+            }
+
+            // the original file is 11 bytes long, so that's where the position pointer should be
+            assertEquals(11, channel.position());
+
+            channel.position(4);
+            assertEquals(4, channel.position());
+        }
+    }
+
+    @Test
+    public void whenGetFileSize_thenCorrect() throws IOException {
+
+        try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); 
+            FileChannel channel = reader.getChannel()) {
+
+            // the original file is 11 bytes long, so that's where the position pointer should be
+            assertEquals(11, channel.size());
+        }
+    }
+
+    @Test
+    public void whenTruncateFile_thenCorrect() throws IOException {
+        String input = "this is a test input";
+
+        FileOutputStream fout = new FileOutputStream("src/test/resources/test_truncate.txt");
+        FileChannel channel = fout.getChannel();
+
+        ByteBuffer buff = ByteBuffer.wrap(input.getBytes());
+        channel.write(buff);
+        buff.flip();
+
+        channel = channel.truncate(5);
+        assertEquals(5, channel.size());
+
+        fout.close();
+        channel.close();
+    }
+}

core-java-modules/core-java-nio/src/test/resources/.gitignore

@@ -0,0 +1,13 @@
+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

core-java-modules/core-java-nio/src/test/resources/test_read.in

@@ -0,0 +1 @@
+Hello world

core-java-modules/core-java-nio/src/test/resources/test_truncate.txt

@@ -0,0 +1 @@
+this 

core-java-modules/core-java-nio/src/test/resources/test_write_using_filechannel.txt

@@ -0,0 +1 @@
+Hello world