Xstream 来实习JavaBean转换成XML

1. 什么作用

  * 可以把JavaBean转换为（序列化为）xml

2. XStream的jar包

  * 核心JAR包：xstream-1.4.7.jar；

  * 必须依赖包：xpp3_min-1.1.4c（XML Pull Parser，一款速度很快的XML解析器）；
3. 使用步骤

  * XStream xstream = new XStream();

  * String xmlStr = xstream.toXML(javabean);
4. 使用细节

  * 别名：把类型对应的元素名修改了

    > xstream.alias("china", List.class)：让List类型生成的元素名为china

    > xstream.alias("province", Province.class)：让Province类型生成的元素名为province

  * 使用为属性：默认类的成员，生成的是元素的子元素！我们希望让类的成员生成元素的属性

    > xstream.useAttributeFor(Province.class, "name")：把Province类的名为name成员，生成<province>元素的name属性

  * 去除Collection类型的成名：我们只需要Collection的内容，而不希望Collection本身也生成一个元素

    > xstream.addImplicitCollection(Province.class, "cities")：让Province类的名为cities(它是List类型的，它的内容还会生成元素)的成名不生成元素

  * 去除类的指定成名，让其不生成xml元素

    > xstream.omitField(City.class, "description")：在生成的xml中不会出现City类的名为description的对应的元素！

具体实例

[java]
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package cn.itcast.demo1;  
  
import java.util.ArrayList;  
import java.util.List;  
  
import org.junit.Test;  
  
import com.thoughtworks.xstream.XStream;  
  
/** 
 * 演示XStream 
 * @author cxf 
 * 
 */  
public class Demo1 {  
    // 返回javabean集合  
    public List<Province> getProinvceList() {  
        Province p1 = new Province();  
        p1.setName("北京");  
        p1.addCity(new City("东城区", "DongChengQu"));  
        p1.addCity(new City("昌平区", "ChangPingQu"));  
          
        Province p2 = new Province();  
        p2.setName("辽宁");  
        p2.addCity(new City("沈阳", "shenYang"));  
        p2.addCity(new City("葫芦岛", "huLuDao"));  
          
        List<Province> provinceList = new ArrayList<Province>();  
        provinceList.add(p1);  
        provinceList.add(p2);  
          
        return provinceList;  
    }  
      
    /** 
<list> --> List类型显示list 
  <cn.itcast.demo1.Province> --> javabean的类型为Province，它元素的名称为类的完整名 
    <name>北京</name> --> javabean的属性名 
    <cities> --> javabean的属性名 
      <cn.itcast.demo1.City> --> 类名 
        <name>东城区</name> --> 属性名 
        <description>DongChengQu</description> --> 属性名 
      </cn.itcast.demo1.City> 
      <cn.itcast.demo1.City> 
        <name>昌平区</name> 
        <description>ChangPingQu</description> 
      </cn.itcast.demo1.City> 
    </cities> 
  </cn.itcast.demo1.Province> 
  <cn.itcast.demo1.Province> 
    <name>辽宁</name> 
    <cities> 
      <cn.itcast.demo1.City> 
        <name>沈阳</name> 
        <description>shenYang</description> 
      </cn.itcast.demo1.City> 
      <cn.itcast.demo1.City> 
        <name>葫芦岛</name> 
        <description>huLuDao</description> 
      </cn.itcast.demo1.City> 
    </cities> 
  </cn.itcast.demo1.Province> 
</list> 
     */  
    @Test  
    public void fun1() {  
        List<Province> proList = getProinvceList();  
        /* 
         * 创建XStream对象 
         * 调用toXML把集合转换成xml字符串 
         */  
        XStream xstream = new XStream();  
        String s = xstream.toXML(proList);  
        System.out.println(s);  
    }  
      
    /* 
     * 别名(alias) 
     * 希望： 
     * * 默认List类型对应<list>元素，希望让List类型对应<china>元素 
     * * 默认Province类型对应<cn.itcast.demo1.Province>，希望让它对应<province> 
     * * 默认City类型对应<cn.itcast.demo1.City>，希望它对应<city>元素 
     */  
    /* 
<china> 
  <province> 
    <name>北京</name> 
    <cities> 
      <city> 
        <name>东城区</name> 
        <description>DongChengQu</description> 
      </city> 
      <city> 
        <name>昌平区</name> 
        <description>ChangPingQu</description> 
      </city> 
    </cities> 
  </province> 
  <province> 
    <name>辽宁</name> 
    <cities> 
      <city> 
        <name>沈阳</name> 
        <description>shenYang</description> 
      </city> 
      <city> 
        <name>葫芦岛</name> 
        <description>huLuDao</description> 
      </city> 
    </cities> 
  </province> 
</china> 
     */  
    @Test  
    public void fun2() {  
        List<Province> proList = getProinvceList();  
        XStream xstream = new XStream();  
        /* 
         * 给指定的类型指定别名 
         */  
        xstream.alias("china", List.class);//给List类型指定别名为china  
        xstream.alias("province", Province.class);//给Province指定别名为province  
        xstream.alias("city", City.class);//给City类型指定别名为city  
          
          
        String s = xstream.toXML(proList);  
        System.out.println(s);  
    }  
      
    /* 
     * 默认javabean的属性都会生成子元素，而现在希望生成元素的属性 
     */  
/* 
<china> 
  <province name="北京"> 
    <cities> 
      <city> 
        <name>东城区</name> 
        <description>DongChengQu</description> 
      </city> 
      <city> 
        <name>昌平区</name> 
        <description>ChangPingQu</description> 
      </city> 
    </cities> 
  </province> 
  <province name="辽宁"> 
    <cities> 
      <city> 
        <name>沈阳</name> 
        <description>shenYang</description> 
      </city> 
      <city> 
        <name>葫芦岛</name> 
        <description>huLuDao</description> 
      </city> 
    </cities> 
  </province> 
 */  
    @Test  
    public void fun3() {  
        List<Province> proList = getProinvceList();  
        XStream xstream = new XStream();  
        xstream.alias("china", List.class);//给List类型指定别名为china  
        xstream.alias("province", Province.class);//给Province指定别名为province  
        xstream.alias("city", City.class);//给City类型指定别名为city  
          
          
        /* 
         * 把Province类型的name属性，生成<province>元素的属性 
         */  
        xstream.useAttributeFor(Province.class, "name");  
          
          
        String s = xstream.toXML(proList);  
        System.out.println(s);        
    }  
  
      
    /* 
     * 去除List类型的属性，只把list中的元素生成xml元素 
     */  
/* 
<china> 
  <province name="北京"> 
    <city> 
      <name>东城区</name> 
      <description>DongChengQu</description> 
    </city> 
    <city> 
      <name>昌平区</name> 
      <description>ChangPingQu</description> 
    </city> 
  </province> 
  <province name="辽宁"> 
    <city> 
      <name>沈阳</name> 
      <description>shenYang</description> 
    </city> 
    <city> 
      <name>葫芦岛</name> 
      <description>huLuDao</description> 
    </city> 
  </province> 
</china> 
 */  
    @Test  
    public void fun4() {  
        List<Province> proList = getProinvceList();  
        XStream xstream = new XStream();  
        xstream.alias("china", List.class);//给List类型指定别名为china  
        xstream.alias("province", Province.class);//给Province指定别名为province  
        xstream.alias("city", City.class);//给City类型指定别名为city  
        xstream.useAttributeFor(Province.class, "name");//把Province类型的name属性，生成<province>元素的属性  
          
          
        /* 
         * 去除<cities>这样的Collection类型的属性 
         * 去除Provice类的名为cities的List类型的属性！ 
         */  
        xstream.addImplicitCollection(Province.class, "cities");  
          
          
        String s = xstream.toXML(proList);  
        System.out.println(s);        
    }  
      
    /** 
     * 去除不想要的javabean属性 
     * 就是让某引起javabean属性，不生成对应的xml元素！ 
     */  
/* 
<china> 
  <province name="北京"> 
    <city> 
      <name>东城区</name> 
    </city> 
    <city> 
      <name>昌平区</name> 
    </city> 
  </province> 
  <province name="辽宁"> 
    <city> 
      <name>沈阳</name> 
    </city> 
    <city> 
      <name>葫芦岛</name> 
    </city> 
  </province> 
</china> 
 */  
    @Test  
    public void fun5() {  
        List<Province> proList = getProinvceList();  
        XStream xstream = new XStream();  
        xstream.alias("china", List.class);//给List类型指定别名为china  
        xstream.alias("province", Province.class);//给Province指定别名为province  
        xstream.alias("city", City.class);//给City类型指定别名为city  
        xstream.useAttributeFor(Province.class, "name");//把Province类型的name属性，生成<province>元素的属性  
        xstream.addImplicitCollection(Province.class, "cities");//去除Provice类的名为cities的List类型的属性！  
          
          
        /* 
         * 让City类的，名为description属性不生成对应的xml元素 
         */  
        xstream.omitField(City.class, "description");  
          
          
        String s = xstream.toXML(proList);  
        System.out.println(s);        
    }  
} 

文章转自：http://blog.csdn.net/JOKER_SAMA/article/details/61197689