Java.io.ObjectInputStream.registerValidation() 方法

package com.codingdict;



import java.io.*;



public class ObjectInputStreamDemo {



   public static void main(String[] args) {

      try {



         // create a new file with an ObjectOutputStream

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

         ObjectOutputStream oout = new ObjectOutputStream(out);



         // write something in the file

         oout.writeObject(new Example());

         oout.flush();



         // create an ObjectInputStream for the file we created before

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



         // read the object and print the string

         Example a = (Example) ois.readObject();



         // print the string that is in Example class

         System.out.println("" + a.s);



         // validate the object

         a.validateObject();





      } catch (Exception ex) {

         ex.printStackTrace();

      }



   }



   static class Example implements Serializable, ObjectInputValidation {

      String s = "Hello World!";



      private String readObject(ObjectInputStream in)

         throws IOException, ClassNotFoundException {



         // call readFields in readObject

         ObjectInputStream.GetField gf = in.readFields();



         // register validation for the object

         in.registerValidation(this, 0);



         // save the string and return it

         return (String) gf.get("s", null);



      }



      public void validateObject() throws InvalidObjectException {

         System.out.println("Validating object...");



         if (this.s.equals("Hello World!")) {

            System.out.println("Validated.");

         } else {

            System.out.println("Not validated.");

         }



      }

   }

}