Java对象转换成xml对象和Java对象转换成JSON对象

　1.把Java对象转换成JSON对象

apache提供的json-lib小工具，它可以方便的使用Java语言来创建JSON字符串。也可以把JavaBean转换成JSON字符串。

json-lib的核心jar包有：　

json-lib.jar，只有两个核心类： JSONObject, JSONArray；

json-lib的依赖jar包有：

commons-lang.jar

commons-beanutils.jar

commons-logging.jar

commons-collections.jar

ezmorph.jar

将person对象转化成json对象：

javabean：

package java转json;

public class Person {
    private String name;
    private int age;
    private String sex;
    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 String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public Person() {
        super();
        // TODO Auto-generated constructor stub
    }
    public Person(String name, int age, String sex) {
        super();
        this.name = name;
        this.age = age;
        this.sex = sex;
    }
    @Override
    public String toString() {
        return "Person [name=" + name + ", age=" + age + ", sex=" + sex + "]";
    }

}

用junit测试：

    @Test
    public void fun() {
        JSONObject jo = new JSONObject();
        jo.put("name", "张三");
        jo.put("age", 12);
        jo.put("sex", "男");
        String s = jo.toString();
        System.out.println(s);
    }

    @Test
    public void fun1() {
        Person p = new Person("liSi", 32, "female");
        JSONObject jo = JSONObject.fromObject(p);// 把JavaBean对象转换成json
        System.out.println(jo.toString());
    }
    // 结果为：{"age":32,"name":"liSi","sex":"female"}

    @Test
    public void fun2() {
        Person p = new Person("liSi", 32, "female");
        Person p1 = new Person("zhangSan", 312, "female");
        Person[] pe = { p, p1 };
        JSONArray ja = JSONArray.fromObject(pe);// 把数组转换成JSONArray
        System.out.println(ja.toString());

    }
    // 结果:[{"age":312,"name":"zhangSan","sex":"female"},{"age":32,"name":"liSi","sex":"female"}]

    @Test
    public void fun3() {
        Person p = new Person("liSi", 32, "female");
        Person p1 = new Person("zhangSan", 312, "female");
        List<Person> l = new ArrayList<Person>();
        l.add(p1);
        l.add(p);
        System.out.println(JSONArray.fromObject(l).toString());// 把list转换成JSONArray
    }
    // 结果为：[{"age":312,"name":"zhangSan","sex":"female"},{"age":32,"name":"liSi","sex":"female"}]

2.把Java对象转换成xml对象

可以到http://xstream.codehaus.org/地址去下载XStream安装包！

XStream的必导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）；

javabean对象仍然用person；

public List<Person> p() {
        Person p1 = new Person("tian", 12, "男");
        Person p2 = new Person("di", 14, "nv");
        Person p3 = new Person("wo", 23, "a");
        List<Person> l = new ArrayList<Person>();
        l.add(p1);
        l.add(p2);
        l.add(p3);
        return l;
    }

    @Test
    public void fun4() {
        List<Person> l = p();
        XStream xs = new XStream();// 创建XStream对象 调用toXML把集合转换成xml字符串
        String s = xs.toXML(l);
        System.out.println(s);
    }
    /*结果
    <list>
      <java转xml.Person>
        <name>tian</name>
        <age>12</age>
        <sex>男</sex>
      </java转xml.Person>
      <java转xml.Person>
        <name>di</name>
        <age>14</age>
        <sex>nv</sex>
      </java转xml.Person>
      <java转xml.Person>
        <name>wo</name>
        <age>23</age>
        <sex>a</sex>
      </java转xml.Person>
    </list>
*/
    @Test
    public void fun2() {
        List<Person> l = p();
        XStream xs = new XStream();
        xs.alias("value", List.class);// 给List起别名为china
        xs.alias("person", Person.class);// 给person起别名为person
        xs.useAttributeFor(Person.class, "name");// 把Person类型的name属性，生成<person>元素的属性
        xs.omitField(Person.class, "age");// 让City类的，名为age属性不生成对应的xml元素
        String s = xs.toXML(l);
        System.out.println(s);
    }
    /*
     * <value>
  <person name="tian">
    <sex>男</sex>
  </person>
  <person name="di">
    <sex>nv</sex>
  </person>
  <person name="wo">
    <sex>a</sex>
  </person>
</value>

     */