ByteArrayOutputStream 类使用实例，,import java.

ByteArrayOutputStream 类使用实例，,import java.

import java.util.*;import java.io.*;public class Person implements Serializable, ObjectInputValidation {  static Map thePeople = new HashMap();  private String name;  private String ss;  public Person(String name, String ss) {    this.name = name;    this.ss = ss;    thePeople.put(ss, name);  }  private void readObject(ObjectInputStream in)   throws IOException, ClassNotFoundException {    in.registerValidation(this, 5);    in.defaultReadObject();  }  public void validateObject() throws InvalidObjectException {    if (thePeople.containsKey(this.ss)) {      throw new InvalidObjectException(this.name + " already exists");    }    else {      thePeople.put(this.ss, this.name);    }  }  public String toString() {    return this.name + "\\t" + this.ss;  }  public static void main(String[] args)   throws IOException, ClassNotFoundException {    Person p1 = new Person("Rusty", "123-45-5678");    Person p2 = new Person("Beth",  "321-45-5678");    Person p3 = new Person("David", "453-45-5678");    Person p4 = new Person("David", "453-45-5678");    Iterator iterator = thePeople.values().iterator();    while (iterator.hasNext()) {      System.out.println(iterator.next());    }    ByteArrayOutputStream bout = new ByteArrayOutputStream();    ObjectOutputStream oout = new ObjectOutputStream(bout);    oout.writeObject(p1);    oout.writeObject(p2);    oout.writeObject(p3);    oout.writeObject(p4);    oout.flush();    oout.close();    ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());    ObjectInputStream oin = new ObjectInputStream(bin);    try {      System.out.println(oin.readObject());      System.out.println(oin.readObject());      System.out.println(oin.readObject());      System.out.println(oin.readObject());    }    catch (InvalidObjectException ex) {      System.err.println(ex);    }    oin.close();    // now empty the map and try again    thePeople.clear();    bin = new ByteArrayInputStream(bout.toByteArray());    oin = new ObjectInputStream(bin);    try {      System.out.println(oin.readObject());      System.out.println(oin.readObject());      System.out.println(oin.readObject());      System.out.println(oin.readObject());    }    catch (InvalidObjectException ex) {      System.err.println(ex);    }    oin.close();    iterator = thePeople.values().iterator();    while (iterator.hasNext()) {      System.out.println(iterator.next());    }     }}//该片段来自于http://byrx.net