nio

whatsmars-common/src/test/java/org/hongxi/java/nio/BufferTest.java

@@ -0,0 +1,40 @@
+package org.hongxi.java.nio;
+
+import java.nio.ByteBuffer;
+
+/**
+ * ByteBuffer
+ * @author shenhongxi 2019/8/15
+ */
+public class BufferTest {
+
+    public static void main(String[] args) {
+        /**
+         * byte[] array = new byte[1024];
+         * ByteBuffer buffer = ByteBuffer.wrap(array);
+         */
+        ByteBuffer buffer = ByteBuffer.allocate(1024);
+
+        buffer.put((byte) 'a');
+        buffer.put((byte) 'b');
+        buffer.put((byte) 'c');
+
+        buffer.flip();
+
+        System.out.println((char) buffer.get());
+        System.out.println((char) buffer.get());
+        System.out.println((char) buffer.get());
+
+        buffer.clear();
+
+        buffer.putInt(30);
+        buffer.putLong(7000000000000L);
+        buffer.putDouble(Math.PI);
+
+        buffer.flip();
+
+        System.out.println(buffer.getInt());
+        System.out.println(buffer.getLong());
+        System.out.println(buffer.getDouble());
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/nio/CharsetsTest.java

@@ -0,0 +1,48 @@
+package org.hongxi.java.nio;
+
+import java.io.File;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.MappedByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.charset.Charset;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.CharsetEncoder;
+
+/**
+ * Charset
+ * @author shenhongxi 2019/8/15
+ */
+public class CharsetsTest {
+
+    public static void main(String[] args) throws Exception {
+        String inputFile = "samplein.txt";
+        String outputFile = "sampleout.txt";
+
+        RandomAccessFile inf = new RandomAccessFile(inputFile, "r");
+        RandomAccessFile outf = new RandomAccessFile(outputFile, "rw");
+        long inputLength = new File(inputFile).length();
+
+        FileChannel inc = inf.getChannel();
+        FileChannel outc = outf.getChannel();
+
+        MappedByteBuffer inputData =
+                inc.map(FileChannel.MapMode.READ_ONLY, 0, inputLength);
+
+        Charset latin1 = Charset.forName("ISO-8859-1");
+        CharsetDecoder decoder = latin1.newDecoder();
+        CharsetEncoder encoder = latin1.newEncoder();
+
+        CharBuffer cb = decoder.decode(inputData);
+
+        // Process char data here
+
+        ByteBuffer outputData = encoder.encode(cb);
+
+        outc.write(outputData);
+
+        inf.close();
+        outf.close();
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/nio/CopyFileTest.java

@@ -0,0 +1,45 @@
+package org.hongxi.java.nio;
+
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+
+/**
+ * FileChannel
+ * @author shenhongxi 2019/8/15
+ */
+public class CopyFileTest {
+
+    public static void main(String[] args) throws Exception {
+        if (args.length < 2) {
+            System.err.println("Usage: java CopyFile infile outfile");
+            System.exit(1);
+        }
+
+        String infile = args[0];
+        String outfile = args[1];
+
+        FileInputStream fin = new FileInputStream(infile);
+        FileOutputStream fout = new FileOutputStream(outfile);
+
+        FileChannel fcin = fin.getChannel();
+        FileChannel fcout = fout.getChannel();
+
+        /**
+         * faster:
+         * ByteBuffer buffer = ByteBuffer.allocateDirect(1024);
+         */
+        ByteBuffer buffer = ByteBuffer.allocate(1024);
+
+        while (true) {
+            buffer.clear();
+            int r = fcin.read(buffer);
+            if (r == -1) {
+                break;
+            }
+            buffer.flip();
+            fcout.write(buffer);
+        }
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/nio/FileLockTest.java

@@ -0,0 +1,39 @@
+package org.hongxi.java.nio;
+
+import java.io.RandomAccessFile;
+import java.nio.channels.FileChannel;
+import java.nio.channels.FileLock;
+
+/**
+ * FileLock
+ * @author shenhongxi 2019/8/15
+ */
+public class FileLockTest {
+    private static final int start = 10;
+    private static final int end = 20;
+
+    public static void main(String[] args) throws Exception {
+        // Get file channel
+        RandomAccessFile raf = new RandomAccessFile("usefilelocks.txt", "rw");
+        FileChannel fc = raf.getChannel();
+
+        // Get lock
+        System.out.println("trying to get lock");
+        FileLock lock = fc.lock(start, end, false);
+        System.out.println("got lock!");
+
+        // Pause
+        System.out.println("pausing");
+        try {
+            Thread.sleep(3000);
+        } catch (InterruptedException ie) {
+        }
+
+        // Release lock
+        System.out.println("going to release lock");
+        lock.release();
+        System.out.println("released lock");
+
+        raf.close();
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/nio/FloatBufferTest.java

@@ -0,0 +1,26 @@
+package org.hongxi.java.nio;
+
+import java.nio.FloatBuffer;
+
+/**
+ * FloatBuffer
+ * @author shenhongxi 2019/8/15
+ */
+public class FloatBufferTest {
+
+    public static void main(String[] args) {
+        FloatBuffer buffer = FloatBuffer.allocate(10);
+
+        for (int i = 0; i < buffer.capacity(); ++i) {
+            float f = (float) Math.sin((((float) i) / 10) * (2 * Math.PI));
+            buffer.put(f);
+        }
+
+        buffer.flip();
+
+        while (buffer.hasRemaining()) {
+            float f = buffer.get();
+            System.out.println(f);
+        }
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/nio/MappedFileTest.java

@@ -5,6 +5,7 @@
 import java.nio.channels.FileChannel;
 
 /**
+ * MappedByteBuffer
  * Created by javahongxi on 2018/1/2.
  */
 public class MappedFileTest {
@@ -16,7 +17,6 @@ static public void main(String args[]) throws Exception {
         FileChannel channel = raf.getChannel();
 
         MappedByteBuffer mbb = channel.map(FileChannel.MapMode.READ_WRITE, start, size);
-
         mbb.put(0, (byte) 97);
         mbb.put(1023, (byte) 122);
 

whatsmars-common/src/test/java/org/hongxi/java/nio/ReadFileTest.java

@@ -0,0 +1,30 @@
+package org.hongxi.java.nio;
+
+import java.io.FileInputStream;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+
+/**
+ * FileChannel
+ * @author shenhongxi 2019/8/15
+ */
+public class ReadFileTest {
+
+    public static void main(String[] args) throws Exception {
+        FileInputStream fin = new FileInputStream("readandshow.txt");
+        FileChannel fc = fin.getChannel();
+
+        ByteBuffer buffer = ByteBuffer.allocate(1024);
+        fc.read(buffer);
+        buffer.flip();
+
+        int i = 0;
+        while (buffer.remaining() > 0) {
+            byte b = buffer.get();
+            System.out.println("Character " + i + ": " + ((char) b));
+            i++;
+        }
+
+        fin.close();
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/nio/ScatterGatherTest.java

@@ -0,0 +1,77 @@
+package org.hongxi.java.nio;
+
+import java.net.InetSocketAddress;
+import java.nio.ByteBuffer;
+import java.nio.channels.ServerSocketChannel;
+import java.nio.channels.SocketChannel;
+
+/**
+ * @author shenhongxi 2019/8/15
+ */
+public class ScatterGatherTest {
+    private static final int firstHeaderLength = 2;
+    private static final int secondHeaderLength = 4;
+    private static final int bodyLength = 6;
+
+    public static void main(String[] args) throws Exception {
+        if (args.length != 1) {
+            System.err.println("Usage: java UseScatterGather port");
+            System.exit(1);
+        }
+
+        int port = Integer.parseInt(args[0]);
+
+        ServerSocketChannel ssc = ServerSocketChannel.open();
+        InetSocketAddress address = new InetSocketAddress(port);
+        ssc.socket().bind(address);
+
+        int messageLength =
+                firstHeaderLength + secondHeaderLength + bodyLength;
+
+        ByteBuffer[] buffers = new ByteBuffer[3];
+        buffers[0] = ByteBuffer.allocate(firstHeaderLength);
+        buffers[1] = ByteBuffer.allocate(secondHeaderLength);
+        buffers[2] = ByteBuffer.allocate(bodyLength);
+
+        SocketChannel sc = ssc.accept();
+
+        while (true) {
+
+            // Scatter-read into buffers
+            int bytesRead = 0;
+            while (bytesRead < messageLength) {
+                long r = sc.read(buffers);
+                bytesRead += r;
+
+                System.out.println("r " + r);
+                for (int i = 0; i < buffers.length; ++i) {
+                    ByteBuffer bb = buffers[i];
+                    System.out.println("b " + i + " " + bb.position() + " " + bb.limit());
+                }
+            }
+
+            // Process message here
+
+            // Flip buffers
+            for (int i = 0; i < buffers.length; ++i) {
+                ByteBuffer bb = buffers[i];
+                bb.flip();
+            }
+
+            // Scatter-write back out
+            long bytesWritten = 0;
+            while (bytesWritten < messageLength) {
+                long r = sc.write(buffers);
+                bytesWritten += r;
+            }
+
+            // Clear buffers
+            for (int i = 0; i < buffers.length; ++i) {
+                ByteBuffer bb = buffers[i];
+                bb.clear();
+            }
+
+            System.out.println(bytesRead + " " + bytesWritten + " " + messageLength);
+        }
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/nio/SliceBufferTest.java

@@ -0,0 +1,36 @@
+package org.hongxi.java.nio;
+
+import java.nio.ByteBuffer;
+
+/**
+ * ByteBuffer
+ * @author shenhongxi 2019/8/15
+ */
+public class SliceBufferTest {
+
+    public static void main(String[] args) {
+        ByteBuffer buffer = ByteBuffer.allocate(10);
+
+        for (int i = 0; i < buffer.capacity(); ++i) {
+            buffer.put((byte) i);
+        }
+
+        buffer.position(3);
+        buffer.limit(7);
+
+        ByteBuffer slice = buffer.slice();
+
+        for (int i = 0; i < slice.capacity(); ++i) {
+            byte b = slice.get(i);
+            b *= 11;
+            slice.put(i, b);
+        }
+
+        buffer.position(0);
+        buffer.limit(buffer.capacity());
+
+        while (buffer.remaining() > 0) {
+            System.out.println(buffer.get());
+        }
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/nio/WriteFileTest.java

@@ -0,0 +1,32 @@
+package org.hongxi.java.nio;
+
+import java.io.FileOutputStream;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+
+/**
+ * FileChannel
+ * @author shenhongxi 2019/8/15
+ */
+public class WriteFileTest {
+    private static final byte message[] = {83, 111, 109, 101, 32,
+            98, 121, 116, 101, 115, 46};
+
+    public static void main(String[] args) throws Exception {
+        FileOutputStream fout = new FileOutputStream("/Users/javahongxi/writesomebytes.txt");
+
+        FileChannel fc = fout.getChannel();
+
+        ByteBuffer buffer = ByteBuffer.allocate(1024);
+
+        for (int i = 0; i < message.length; ++i) {
+            buffer.put(message[i]);
+        }
+
+        buffer.flip();
+
+        fc.write(buffer);
+
+        fout.close();
+    }
+}