Java by API/java.io/OutputStream

extends OutputStream

 
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
public class Main {
  public static void main(String[] argv) throws Exception {
    ByteBuffer buf = ByteBuffer.allocate(10);
    OutputStream os = new ByteBufferBackedOutputStream(buf);
    InputStream is = new  ByteBufferBackedInputStream(buf);
  }
}
class ByteBufferBackedInputStream extends InputStream{
  
  ByteBuffer buf;
  ByteBufferBackedInputStream( ByteBuffer buf){
    this.buf = buf;
  }
  public synchronized int read() throws IOException {
    if (!buf.hasRemaining()) {
      return -1;
    }
    return buf.get();
  }
  public synchronized int read(byte[] bytes, int off, int len) throws IOException {
    len = Math.min(len, buf.remaining());
    buf.get(bytes, off, len);
    return len;
  }
}
class ByteBufferBackedOutputStream extends OutputStream{
  ByteBuffer buf;
  ByteBufferBackedOutputStream( ByteBuffer buf){
    this.buf = buf;
  }
  public synchronized void write(int b) throws IOException {
    buf.put((byte) b);
  }
  public synchronized void write(byte[] bytes, int off, int len) throws IOException {
    buf.put(bytes, off, len);
  }
  
}

OutputStream: close()

  
/*
 * Output:
 * 
 * 
 * 
 *  
 */
import java.io.*;
public class MainClass {
  
  public static void main(String args[]) throws Exception {
    byte buf[] = new byte[]{66,67,68,69};
    OutputStream f0 = new FileOutputStream("file1.txt");
    OutputStream f1 = new FileOutputStream("file2.txt");
    OutputStream f2 = new FileOutputStream("file3.txt");
    for (int i = 0; i < buf.length; i++) {
      f0.write(buf[i]);
    }
    f0.close();
    f1.write(buf);
    f1.close();
    f2.write(buf, buf.length / 4, buf.length / 2);
    f2.close();
  }
}

OutputStream: flush()

  
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class Main {
  public static void main(String args[]) throws IOException {
    int howMany = 20;
    // To avoid resizing the buffer, calculate the size of the
    // byte array in advance.
    ByteArrayOutputStream bout = new ByteArrayOutputStream(howMany * 4);
    DataOutputStream dout = new DataOutputStream(bout);
    for (int i = 0; i <= 20; i++) {
      dout.writeInt(i);
    }
    FileOutputStream fout = new FileOutputStream("fibonacci.dat");
    try {
      bout.writeTo(fout);
      fout.flush();
    } finally {
      fout.close();
    }
  }
}

OutputStream: write(byte[] b, int off, int len)

  
/*
 * Output:
 * 
 * 
 * 
 *  
 */
import java.io.*;
public class MainClass {
  
  public static void main(String args[]) throws Exception {
    byte buf[] = new byte[]{66,67,68,69};
    OutputStream f0 = new FileOutputStream("file1.txt");
    OutputStream f1 = new FileOutputStream("file2.txt");
    OutputStream f2 = new FileOutputStream("file3.txt");
    for (int i = 0; i < buf.length; i++) {
      f0.write(buf[i]);
    }
    f0.close();
    f1.write(buf);
    f1.close();
    f2.write(buf, buf.length / 4, buf.length / 2);
    f2.close();
  }
}

OutputStream: write(byte byteValue)

  
/*
 * Output:
 * 
 * 
 * 
 *  
 */
import java.io.*;
public class MainClass {
  
  public static void main(String args[]) throws Exception {
    byte buf[] = new byte[]{66,67,68,69};
    OutputStream f0 = new FileOutputStream("file1.txt");
    OutputStream f1 = new FileOutputStream("file2.txt");
    OutputStream f2 = new FileOutputStream("file3.txt");
    for (int i = 0; i < buf.length; i++) {
      f0.write(buf[i]);
    }
    f0.close();
    f1.write(buf);
    f1.close();
    f2.write(buf, buf.length / 4, buf.length / 2);
    f2.close();
  }
}

OutputStream: write(byte[] values)

  
/*
 * Output:
 * 
 * 
 * 
 *  
 */
import java.io.*;
public class MainClass {
  
  public static void main(String args[]) throws Exception {
    byte buf[] = new byte[]{66,67,68,69};
    OutputStream f0 = new FileOutputStream("file1.txt");
    OutputStream f1 = new FileOutputStream("file2.txt");
    OutputStream f2 = new FileOutputStream("file3.txt");
    for (int i = 0; i < buf.length; i++) {
      f0.write(buf[i]);
    }
    f0.close();
    f1.write(buf);
    f1.close();
    f2.write(buf, buf.length / 4, buf.length / 2);
    f2.close();
  }
}