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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怎么样构造函数复制一个对象
java复制对象:
一、使用clone。对象可克隆的类必须实现Cloneable接口,并且clone方法是浅克隆。
二、类实现Serializable,用ObjectOutputStream、ObjectInputStream 来复制对象。
三、可以直接new一个对象,赋值!
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;
}