java对象与xml文件转换

XStream 是一个轻量级的、简单易用的开放源代码Java™库，用于将 Java 对象序列化为 XML 或者再转换回来

XStream 对象相当Java对象和XML之间的转换器，转换过程是双向的。创建XSteam对象的方式很简单，只需要new XStream()即可。
Java 到xml，用toXML()方法。
Xml到Java，用fromXML()方法。

在没有任何设置默认情况下，java到xml的映射，是java成员名对应xml的元素名，java类的全名对应xml根元素的名字。而实际中，往往是xml和java类都有了，要完成相互转换，必须进行别名映射。

XStream 的编码:
本身并没有实现编码，必须依靠java.io.Writer来实现输出编码的转换。

XStream 的常用方法
xstream.omitField(mytest.class,"name");定义某一个属性的值不进行xml序列化。
xstream.alias("cat", Cat.class); 对某一个类进行别名定义
xstream.aliasField("age",Cat.class, "mAge");对某一个类的属性进行别名定义。
xstream.useAttributeFor(String.class);对所有String类型的字段定义为属性tag显示
xstream.useAttributeFor("name".String.class);对所有String类型的字段名成为name 定义为属性tag显示

package com.ljh.bean;
public class Address {
private int id;
private String addressName;
public Address(){}
public Address(int id, String addressName) {
this.id= id;
this.addressName= addressName;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id= id;
}
public String getAddressName() {
return addressName;
}
public void setAddressName(String addressName) {
this.addressName= addressName;
}
}

package com.ljh.bean;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class Person {
private int id;
private String name;
private int age;
private String birthday;
private List<Address> addresses = new ArrayList<Address>();
private Date date = new Date();
public Person(int id, String name, int age,String birthday) {
this.id= id;
this.name= name;
this.age= age;
this.birthday= birthday;
}
public List<Address> getAddresses() {
return addresses;
}
public void setAddresses(List<Address> addresses) {
this.addresses= addresses;
}
public Date getDate() {
return date;
}
public void setDate(Date date) {
this.date= date;
}
public String getBirthday() {
return birthday;
}

public void setBirthday(String birthday) {
this.birthday= birthday;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id= id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name= name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age= age;
}
public void add(Address address){
addresses.add(address);
}
}

package com.ljh.xstream;
import java.io.PrintWriter;
import com.ljh.bean.Address;
import com.ljh.bean.Person;
import com.thoughtworks.xstream.XStream;
public class XStreamTest {
public static void main(String[] args) throws Exception {
Address address1 = new Address(1,"北京");
Address address2 = new Address(2,"天津");
Address address3 = new Address(3,"上海");
Person p = new Person(1,"ljh",38,"2111-11-11 11:11");
p.add(address1);
p.add(address2);
p.add(address3);
XStream xstream = new XStream();
//对某一个类进行别名定义
xstream.alias("地址",Address.class);
xstream.alias("联系人",Person.class);
//对某一个类的属性进行别名定义
xstream.aliasField("编号",Person.class, "id");
xstream.aliasField("姓名",Person.class, "name");
xstream.aliasField("年龄",Person.class, "age");
xstream.aliasField("联系方式",Person.class, "addresses");
xstream.aliasField("编号",Address.class, "id");
xstream.aliasField("名称",Address.class, "addressName");
xstream.aliasField("生日",Person.class, "birthday");
//定义某一个属性的值不进行xml序列化。
xstream.omitField(Person.class,"date");
//对id字段定义为属性显示
xstream.useAttributeFor(Person.class,"id");
xstream.useAttributeFor(Address.class,"id");
//对所有String类型的字段名成为name 定义为属性tag显示
//xstream.useAttributeFor("name".String.class);
xstream.toXML(p,new PrintWriter("c:\\person.xml","utf-8"));
}
}