「java对象copy」Java对象序列化
今天给各位分享java对象copy的知识，其中也会对Java对象序列化进行解释，如果能碰巧解决你现在面临的问题，别忘了关注本站，现在开始吧！
本文目录一览：
java对象值的copy
让B成为A的子类，使用JAVA的反射机制，自己写一个子类拷贝父类的属性的函数，这样无论父类有几个属性都可以不用修改代码了。
参考一下：
java 如何复制一个对象?
给你个小例子
class test implents Cloneable
{
test t1 = new test();
test t2 = null;
try {
t2 = (test)t1.clone();
} catch (CloneNotSupportedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
用clone()方法，不过在对象重载了Object的clone才能用。Object的clone方法是protected。
java 代码实现对象的拷贝
package com.teven.comefromnet;
/**
* Name:C.java
* Founction:
* Created:2011-9-15
* @author :teven
*/
public class CloneTest {
static class A implements Cloneable{
int i=1;
@Override
protected A clone() throws CloneNotSupportedException {
return (A)super.clone();
}
}
static class B extends A{
int j=2;
@Override
protected B clone() throws CloneNotSupportedException {
return (B)super.clone();
}
}
static class C extends B{
int k=3;
@Override
protected C clone() throws CloneNotSupportedException {
return (C)super.clone();
}
}
public static void main(String[] args) throws CloneNotSupportedException {
A a = new CloneTest.A();
A aa = (A) a.clone();
System.out.println("before clone a.i = "+ a.i+" after clone aa.i=" +aa.i);
B b = new CloneTest.B();
B bb= (B) b.clone();
System.out.println("before clone b.j = "+ b.j+" after clone bb.j=" +bb.j);
C c = new CloneTest.C();
C cc= (C) c.clone();
System.out.println("before clone c.k = "+ c.k+" after clone cc.k=" +cc.k);
}
}
如何复制一个java对象
/**
* 复制对象
*
* @param srcObj
* @return
*/
public static Object depthClone(Object srcObj) {
if (srcObj == null) {
return null;
}
Object cloneObj = null;
ByteArrayOutputStream out = null;
ObjectOutputStream oo = null;
ByteArrayInputStream in = null;
ObjectInputStream oi = null;
try {
out = new ByteArrayOutputStream();
oo = new ObjectOutputStream(out);
oo.writeObject(srcObj);
in = new ByteArrayInputStream(out.toByteArray());
oi = new ObjectInputStream(in);
cloneObj = oi.readObject();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} finally {
if (out != null) {
try {
out.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
if (oo != null) {
try {
oo.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
if (in != null) {
try {
in.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
if (oi != null) {
try {
oi.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
return cloneObj;
}
Java中，复制一个对象，有什么好的方法
使用Java的反射机制实现：为了能更好的区分，写成了两个类，可以运行下面的代码看看效果
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class Test {
public static void main(String[] args) throws Exception {
Customer1 c1 = new Customer1();
c1.setName("c1");
ListString list = new ArrayListString();
list.add("1");
list.add("2");
c1.setList(list);
MapString,String map = new HashMapString, String();
map.put("map1", "map1");
map.put("map2", "map2");
c1.setMap(map);
Customer2 c2 = new Customer2();
//
Class c = c1.getClass();
Class class2 = c2.getClass();
Field fields[] = c.getDeclaredFields();
for (int i = 0; i fields.length; i++) {
Field field = fields[i];
String fieldName = field.getName();
String firstLetter = fieldName.substring(0, 1).toUpperCase();
String getMethodName = "get" + firstLetter + fieldName.substring(1);
String setMethodName = "set" + firstLetter + fieldName.substring(1);
Method getMethod = c.getMethod(getMethodName, new Class[] {});
Method setMethod = class2.getMethod(setMethodName,
new Class[] { field.getType() });
Object value = getMethod.invoke(c1, new Object[] {});
setMethod.invoke(c2, new Object[] { value });
}
System.out.println(c2.getName());
System.out.println(c2.getList());
System.out.println(c2.getMap());
}
}
class Customer1 {
private String name;
private ListString list;
private MapString, String map;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public ListString getList() {
return list;
}
public void setList(ListString list) {
this.list = list;
}
public MapString, String getMap() {
return map;
}
public void setMap(MapString, String map) {
this.map = map;
}
}
class Customer2 {
private String name;
private ListString list;
private MapString, String map;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public ListString getList() {
return list;
}
public void setList(ListString list) {
this.list = list;
}
public MapString, String getMap() {
return map;
}
public void setMap(MapString, String map) {
this.map = map;
}
}
java对象copy的介绍就聊到这里吧，感谢你花时间阅读本站内容，更多关于Java对象序列化、java对象copy的信息别忘了在本站进行查找喔。
发布于：2022-11-25，除非注明，否则均为原创文章，转载请注明出处。