ByteArrayOutputStream（字节数组输出流） 示例

//Demonstrate ByteArrayOutputStream.
import java.io.*;
class ByteArrayOutputStreamDemo{
 public static void main(String[] args) throws IOException{
  ByteArrayOutputStream f = new ByteArrayOutputStream();
  String s = "This should end up in the array";
  byte buf[] = s.getBytes();

  f.write(buf);
  System.out.println("Buffer as a string");
  System.out.println(f.toString());
  System.out.println("Into array");
  byte b[] = f.toByteArray();
  for(int i=0;i<b.length;i++){
   System.out.print((char)b[i]);
  }
  System.out.println("\nTo an OutputStream()");
  OutputStream f2 = new FileOutputStream("text.txt");
  f.writeTo(f2);
  f2.close();
  System.out.println("Doing a reset");
  f.reset();
  for(int i=0;i<3;i++){
   f.write('X');
  }
  System.out.println(f.toString());
 }
}