json-lib 序列化和反序列化-白红宇

可以使用json-lib来序列化对象

依赖的jar包：

如何使用json-lib来序列化java对象呢？

实例：

       Java代码   
@Test  
    public void test_serialize(){  
        Class2 c=new Class2();  
        List<Student>students=new ArrayList<Student>();  
        Student student=new Student();  
        Map<String, Object> attribute =new HashMap<String, Object>();  
        attribute.put("p1", "v1");  
        attribute.put("p2", "v2");  
        student.setAttribute(attribute);  
        students.add(student);  
        c.setStudents(students);  
        c.setClassName("计算机0705");  
        JSONObject js = JSONObject.fromObject(c/*, jsonConfig*/);  
        System.out.println(js.toString());  
    }  

运行结果如下：

{"classAttribute":null,"className":"计算机0705","count":0,"students":[{"addrr":null,"age":0,"attribute":{"p2":"v2","p1":"v1"},"hobby":"","name":""}]}

实例：

       Java代码   
@Test  
    public void test_serialize2(){  
        Class2 c=new Class2();  
        List<Student>students=new ArrayList<Student>();  
        Student student=new Student();  
        Map<String, Object> attribute =new HashMap<String, Object>();  
        attribute.put("p1", "v1");  
        attribute.put("p2", "v2");  
        student.setAttribute(attribute);  
        students.add(student);  
        c.setStudents(students);  
        c.setClassName("计算机0705");  
          
        Map<String, Object> classAttribute =new HashMap<String, Object>();  
        classAttribute.put("pp1", "vv1");  
        classAttribute.put("pp2", "vv2");  
          
          
        Teacher t=new Teacher();  
        t.setName("熊应标");  
        t.setTitle("语文老师");  
          
        c.setClassAttribute(classAttribute);  
//      One2One one=new One2One();  
//      one.setC(c);  
//      one.setT(t);  
          
        JSONObject js = JSONObject.fromObject(c/*, jsonConfig*/);  
        System.out.println(js.toString());  
    }  

运行结果如下：

{"classAttribute":{"pp1":"vv1","pp2":"vv2"},"className":"计算机0705","count":0,"students":[{"addrr":null,"age":0,"attribute":{"p2":"v2","p1":"v1"},"hobby":"","name":""}]}

如何使用json-lib反序列化（把string转化为Java对象）？

参考：http://hw1287789687.iteye.com/admin/blogs/1993048

实例：

       Java代码   
@Test  
    public  void test_reserialize(){  
//      String jsonInput="{\"className\":\"计算机0705\",\"count\":0,\"students\":[{\"addrr\":null,\"age\":0,\"hobby\":\"\",\"name\":\"\"}]}";  
        String jsonInput="{\"classAttribute\":{\"pp1\":\"vv1\",\"pp2\":\"vv2\"},\"className\":\"计算机0705\",\"count\":0,\"students\":[{\"addrr\":null,\"age\":0,\"attribute\":{\"p2\":\"v2\",\"p1\":\"v1\"},\"hobby\":\"\",\"name\":\"\"}]}";  
        JSONObject js = JSONObject.fromObject(jsonInput);  
          
        JsonConfig jsonConfig = new JsonConfig();  
  
        jsonConfig.setRootClass(Class2.class);  
        Map<String, Class> classMap = new HashMap<String, Class>();  
        classMap.put("students", Student.class); // 指定JsonRpcRequest的request字段的内部类型  
        jsonConfig.setClassMap(classMap);  
          
          
          
        Class2 one = (Class2) JSONObject.toBean(js, jsonConfig/*java.lang.ClassCastException: net.sf.ezmorph.bean.MorphDynaBean cannot be cast to*/);  
        System.out.println(one.getClassName());  
        Map<String, Object> attribute =one.getStudents().get(0).getAttribute();  
        System.out.println(attribute);  
          
    }  

运行结果：

计算机0705

{p2=v2, p1=v1}

序列化时如何删除属性值为null的属性

参考：

下面的事不合要求的：

{"addrr":{"country":"中国","state":"湖北省","street":"清河"},"age":25,"hobby":"","name":"黄威"}

hobby的值为空，应该被过滤掉的。

解决方法：

JsonConfig jsonConfig = new JsonConfig();

jsonConfig.setJsonPropertyFilter(new PropertyFilter() {

publicboolean apply(Object source, String name, Object value) {

// System.out.println(name);

// System.out.println(value);

if (value == null || (value instanceof String)

&& ((String) value).equals("")) {

returntrue;

}

returnfalse;

}

});

JSONObject js = JSONObject.fromObject(student, jsonConfig);

参考:http://hw1287789687.iteye.com/blog/1997956