java对象和json对象之间互相转换例子

import java.util.ArrayList;  
    import java.util.Collection;  
    import java.util.Iterator;  
    import java.util.List;  

    import net.sf.json.JSONArray;  
    import net.sf.json.JSONObject;  

    public class MainClass {  

        public static void main(String[] args) {  
            TestJsonBean();  
            TestJsonAttribute();  
            TestJsonArray();          
        }  

        @SuppressWarnings("rawtypes")  
        private static void TestJsonArray() {  
            Student student1 = new Student();  
            student1.setId(1);  
            student1.setName("jag");  
            student1.setSex("man");  
            student1.setAge(25);  
            student1.setHobby(new String[]{"篮球","游戏"});  

            Student student2 = new Student();  
            student2.setId(2);  
            student2.setName("tom");  
            student2.setSex("woman");  
            student2.setAge(23);  
            student2.setHobby(new String[]{"上网","跑步"});  

            List<Student> list = new ArrayList<Student>();  
            list.add(student1);  
            list.add(student2);  

            JSONArray jsonArray = JSONArray.fromObject(list);  
            System.out.println(jsonArray.toString());  

            JSONArray new_jsonArray=JSONArray.fromObject(jsonArray.toArray());  
            Collection java_collection=JSONArray.toCollection(new_jsonArray);  
            if(java_collection!=null && !java_collection.isEmpty())  
            {  
                Iterator it=java_collection.iterator();  
                while(it.hasNext())  
                {  
                    JSONObject jsonObj=JSONObject.fromObject(it.next());  
                    Student stu=(Student) JSONObject.toBean(jsonObj,Student.class);  
                    System.out.println(stu.getName());  
                }  
            }  
        }  

        private static void TestJsonAttribute() {  
            /** 
             * 创建json对象并为该对象设置属性 
             */  
            JSONObject jsonObj = new JSONObject();  
            jsonObj.put("Int_att",25);//添加int型属性  
            jsonObj.put("String_att","str");//添加string型属性  
            jsonObj.put("Double_att",12.25);//添加double型属性  
            jsonObj.put("Boolean_att",true);//添加boolean型属性  
            //添加JSONObject型属性  
            JSONObject jsonObjSon = new JSONObject();  
            jsonObjSon.put("id", 1);  
            jsonObjSon.put("name", "tom");  
            jsonObj.put("JSONObject_att",jsonObjSon);  
            //添加JSONArray型属性  
            JSONArray jsonArray = new JSONArray();  
            jsonArray.add("array0");  
            jsonArray.add("array1");  
            jsonArray.add("array2");  
            jsonArray.add("array3");  
            jsonObj.put("JSONArray_att", jsonArray);  
            System.out.println(jsonObj.toString());  
            System.out.println("Int_att:"+jsonObj.getInt("Int_att"));  
            System.out.println("String_att:"+jsonObj.getString("String_att"));  
            System.out.println("Double_att:"+jsonObj.getDouble("Double_att"));  
            System.out.println("Boolean_att:"+jsonObj.getBoolean("Boolean_att"));  
            System.out.println("JSONObject_att:"+jsonObj.getJSONObject("JSONObject_att"));  
            System.out.println("JSONArray_att:"+jsonObj.getJSONArray("JSONArray_att"));  
        }  

        /** 
         * java对象与json对象互相转换 
         */  
        private static void TestJsonBean() {  
            /** 
             * 创建java对象 
             */  
            Student student = new Student();  
            student.setId(1);  
            student.setName("jag");  
            student.setSex("man");  
            student.setAge(25);  
            student.setHobby(new String[]{"篮球","上网","跑步","游戏"});  
            /** 
             * java对象转换成json对象，并获取json对象属性 
             */  
            JSONObject jsonStu = JSONObject.fromObject(student);  
            System.out.println(jsonStu.toString());  
            System.out.println(jsonStu.getJSONArray("hobby"));  
            /** 
             * json对象转换成java对象，并获取java对象属性 
             */  
            Student stu = (Student) JSONObject.toBean(jsonStu, Student.class);  
            System.out.println(stu.getName());  
            /** 
             * 创建json对象 
             */  
            JSONObject jsonObj = new JSONObject();  
            jsonObj.put("id",1);  
            jsonObj.put("name","张勇");  
            jsonObj.put("sex","男");  
            jsonObj.put("age",24);  
            //jsonObj.put("hobby",new String[]{"上网","游戏","跑步","音乐"});  
            //System.out.println(jsonObj.toString());  
            /** 
             * json对象转换成java对象 
             */  
            Student stud = (Student) JSONObject.toBean(jsonObj,Student.class);  
            System.out.println(stud.getName());       
        }  
    }  

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