Javaシリアル化アクセスによるオブジェクト複製例の詳細説明

public class DeepCloneTest { private class CloneTest {  private Long myLong = new Long(1); } public static void main(String args[]) {  new DeepCloneTest().Test(); } public void Test() {  CloneTest ct1 = new CloneTest();  CloneTest ct2 = ct1;  // to see if ct1 and ct2 are one same reference.  System.out.println("ct1: " + ct1);  System.out.println("ct2: " + ct2);  // if ct1 and ct2 point to one same object, then ct1.myLong == ct2.myLong.  System.out.println("ct1.myLong: " + ct1.myLong);  System.out.println("ct2.myLong: " + ct2.myLong);  // we change ct2's myLong  ct2.myLong = 2L;  // to see whether ct1's myLong was changed.  System.out.println("ct1.myLong: " + ct1.myLong);  System.out.println("ct2.myLong: " + ct2.myLong); }}

public class DeepCloneTest{ // must implements Cloneable. private class CloneTest implements Cloneable{  private Object o = new Object();  public CloneTest clone() {   CloneTest ct = null;   try {    ct = (CloneTest)super.clone();   } catch (CloneNotSupportedException e) {    e.printStackTrace();   }   return ct;  } } public static void main(String args[]) {  new DeepCloneTest().Test(); } public void Test() {  CloneTest ct1 = new CloneTest();  CloneTest ct2 = ct1.clone();  // to see if ct1 and ct2 are one same reference.  System.out.println("ct1: " + ct1);  System.out.println("ct2: " + ct2);  // whether ct1.o == ct2.o ? yes  System.out.println("ct1.o " + ct1.o);  System.out.println("ct1.o " + ct1.o); }}

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
public class DeepCloneTest {
 // must implements Cloneable.
 private class CloneTest implements Serializable{
  private static final long serialVersionUID = 1L;
  private Object o = new Object();
  public CloneTest deepClone() {
   CloneTest ct = null;
   try {
    ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
             ObjectOutputStream oos = new ObjectOutputStream(baos); 
             oos.writeObject(this);
             ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray()); 
             ObjectInputStream ois= new ObjectInputStream(bais); 
             ct = (CloneTest)ois.readObject(); 
   } catch (IOException e) {
    e.printStackTrace();
   } catch (ClassNotFoundException e) {
    e.printStackTrace();
   }
   return ct;
  }
 }
 public static void main(String args[]) {
  new DeepCloneTest().Test();
 }
 public void Test() {
  CloneTest ct1 = new CloneTest();
  CloneTest ct2 = ct1.deepClone();
  // to see if ct1 and ct2 are one same reference.
  System.out.println("ct1: " + ct1);
  System.out.println("ct2: " + ct2);
  // whether ct1.o == ct2.o ? no
  System.out.println("ct1.o " + ct1.o);
  System.out.println("ct1.o " + ct1.o);
 }
}