Java.io.ObjectOutputStream.replaceObject() 方法

package com.codingdict;



import java.io.*;



public class ObjectOutputStreamDemo extends ObjectOutputStream {



   public ObjectOutputStreamDemo(OutputStream out) throws IOException {

      super(out);

   }



   public static void main(String[] args) {

      Object s = "Hello World!";

      Object s2 = "Bye World!";



      try {



         // create a new file with an ObjectOutputStream

         FileOutputStream out = new FileOutputStream("test.txt");

         ObjectOutputStreamDemo oout = new ObjectOutputStreamDemo(out);



         // write something in the file

         oout.writeObject(s);

         oout.flush();



         // enable object replacing

         oout.enableReplaceObject(true);



         // replace object

         System.out.println("" + oout.replaceObject(s2));



         // close the stream

         oout.close();



         // create an ObjectInputStream for the file we created before

         ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt"));



         // read and print an int

         System.out.println("" + (String) ois.readObject());



      } catch (Exception ex) {

         ex.printStackTrace();

      }



   }

}