浅谈java转成json编码格式技术

json编码;是一个轻量级的数据存储和传输的语言

  

   在java中需要引入json相关的包,引包方式在工程的lib下就可以了

 

JSON与JAVA数据的转换（JSON 即 JavaScript Object Natation，它是一种轻量级的数据交换格式，非

 

常适合于服务器与 JavaScript 之间的数据的交互)

 

 

json的表达式相当于JavaScript的原始类的声明方式相似

var obj={
   name:"javascript",
   age:20
};

 

将java转成json的编码表达式;

 

1, 创建json的基本对象

 

 String str="{}";//将java转化为json必须要先创建需要转换的数据
  JSONObject jsonobj =new JSONObject.fromObject(str);//将java数据装换为json的编码方式

 

2,使用for循环几个数字放入创建的json对象中

 for(int i=0;i<5;i++){
  jsonobj.put("json"+i,i);//将java数据放到json对象中去
   // jsonobj.put("json"+i, i);和put的执行结果一样
  // jsonobj.accumulate("json"+i, i);和put的执行结果一样
   System.out.println(jsonobj.toString());//打印json的数据
  }

      结果:

 {"id0":0}

{"id0":0,"id1":1}

{"id0":0,"id1":1,"id2":2}

{"id0":0,"id1":1,"id2":2,"id3":3}

{"id0":0,"id1":1,"id2":2,"id3":3,"id4":4}

 

3,使用put向json中放一个JSONObject对象

		// 创建json的基本对象
		String date = "{}";
		JSONObject jsonobj = JSONObject.fromObject(date);

		// 使用int将数值放到json
		for (int j = 0; j < 5; j++) {
			// jsonobj.put("id"+j, j);
			// jsonobj.accumulate("id"+j, j);
			jsonobj.element("id" + j, j);
			//System.out.println(jsonobj.toString());
		}

		// put 一个JSONObject对象
		JSONObject obj1 = JSONObject.fromObject(date);
		for (int n = 0; n < 5; n++) {
            obj1.put("date"+n, n);//对象中放入5个数据
            jsonobj.put("jsonobj", obj1);//将创建的obj1放入jsonobj对象中
            System.out.println(jsonobj.toString());
             
		}

 结果:

{"id0":0,"id1":1,"id2":2,"id3":3,"id4":4,"jsonobj":{"date0":0}}

{"id0":0,"id1":1,"id2":2,"id3":3,"id4":4,"jsonobj":{"date0":0,"date1":1}}

{"id0":0,"id1":1,"id2":2,"id3":3,"id4":4,"jsonobj":{"date0":0,"date1":1,"date2":2}}

{"id0":0,"id1":1,"id2":2,"id3":3,"id4":4,"jsonobj":{"date0":0,"date1":1,"date2":2,"date3":3}}

 

{"id0":0,"id1":1,"id2":2,"id3":3,"id4":4,"jsonobj":{"date0":0,"date1":1,"date2":2,"date3":3,"date4":4}}

 

 

4,将数组添加到json中

 

// 创建json的基本对象
	String date = "{}";
	JSONObject jsonobj = JSONObject.fromObject(date);
   //,将数组转化为JSONonject
     String[] str={"json","ajax","Jquery","javascript"};//创建要转化的数组的值
    jsonobj.put("arr", str);//放到json对象中
    System.out.println(jsonobj.toString());
          

 结果:

{"arr":["json","ajax","Jquery","javascript"]}

 

  5,将list放到json中

String date = "{}";
JSONObject jsonobj = JSONObject.fromObject(date);

ArrayList<String> list = new ArrayList<String>();  
          list.add("json");
          list.add("java");
          list.add("android");
          jsonobj.put("jsonobj", list);
          System.out.println(jsonobj.toString());

 结果:{"jsonobj":["json","java","android"]}

 

6,将map放到json中

   

		String date = "{}"; 
		JSONObject jsonobj = JSONObject.fromObject(date);//创建转化的对象
        Map<String,Object> map = new HashMap<String, Object>();//创建map队列
        map.put("map1", "json");  
        map.put("map2", "java");  
        map.put("map3", "android");  
        jsonobj.put("map", map);  //放到json中
        System.out.println(jsonobj.toString());  

 结果:

 

{"map":{"map3":"android","map2":"java","map1":"json"}}

 

7,使用 putAll 将json放到队列中

    

	String date = "{}"; 
		JSONObject jsonobj = JSONObject.fromObject(date);//创建转化的对象
        Map<String,Object> map = new HashMap<String, Object>();  
        map.put("map1", "json");  
        map.put("map2", "android");  
        map.put("map3", "Jquery");  
        jsonobj.putAll(map);  
        System.out.println(jsonobj.toString());  
        

 结果:

{"map3":"Jquery","map2":"android","map1":"json"}

 

8,区分put和putAll的区别:

 

  put;会有一个对象  {"map":{"map3":"android","map2":"java","map1":"json"}}

 

  putAll没有   {"map3":"Jquery","map2":"android","map1":"json"}

 

 

9, 组合: (返回的结果value是一个对象数组) 

		//思路:
//		  1,创建转化为json的对象
//		  2,创建ArrayList队列存放转化的json对象
//		  3,使用for循环3次,创建json的对象,向循环创建的json添加值
//		  4,将循环创建的json对象放到队列中
//		  5,将队列添加到json中
    	String date = "{}"; 
		JSONObject jsonobj = JSONObject.fromObject(date);//创建转化的对象
		ArrayList<JSONObject> list = new ArrayList<JSONObject>();//创建队列  
        for(int i=0; i<3; i++){  //循环
         JSONObject json  = JSONObject.fromObject(date); //转化的java
         json.put("aaaa"+i, i);  
         json.put("bbbb"+i, i);  
         json.put("cccc"+i, i);  
         list.add(json);  
        }  
        jsonobj.put("succList", list);  
        System.out.println(jsonobj.toString());  
          

 结果:

{"succList":[

{"aaaa0":0,"bbbb0":0,"cccc0":0},

{"aaaa1":1,"bbbb1":1,"cccc1":1},

{"aaaa2":2,"bbbb2":2,"cccc2":2}

 ] }

 

 

10,json的组合,返回的结果的值是一个数组

 

	// 创建json的基本对象
		String date = "{}";
		JSONObject jsonobj = JSONObject.fromObject(date);
		String[] str={"json","ajax","Jquery","javascript"};//数组
      jsonobj.put("arr", str);	
		ArrayList<JSONObject> list = new ArrayList<JSONObject>();//创建队列  
        for(int i=0; i<3; i++){  //循环
         JSONObject json  = JSONObject.fromObject(date); //转化的java
         json.put("aaaa"+i, i);  
         json.put("bbbb"+i, i);  
         json.put("cccc"+i,str );  //添加一个数组
         list.add(json);  
        }  
        jsonobj.put("succList", list);  
        System.out.println(jsonobj.toString());  

 结果:

{"arr":["json","ajax","Jquery","javascript"],

     "succList":[{"aaaa0":0,"bbbb0":0,"cccc0":["json","ajax","Jquery","javascript"]},

     {"aaaa1":1,"bbbb1":1,"cccc1":["json","ajax","Jquery","javascript"]},

      {"aaaa2":2,"bbbb2":2,"cccc2":["json","ajax","Jquery","javascript"]}

 

  ]}

 

 

11,组合,任意的嵌套;

// 创建json的基本对象
		String date = "{}";
		JSONObject jsonobj = JSONObject.fromObject(date);
		String[] str={"json","ajax","Jquery","javascript"};//数组
		//转化java的json嵌套到json中
		JSONObject jsonDemo  = JSONObject.fromObject(date); 
		for(int n=0;n<3;n++){
			jsonDemo.put("组合"+n, n);
		}
		ArrayList<JSONObject> list = new ArrayList<JSONObject>();//创建队列  
        for(int i=0; i<3; i++){  //循环
         JSONObject json  = JSONObject.fromObject(date); //转化的java
         json.put("aaaa"+i, jsonDemo);  //嵌套的json
         json.put("bbbb"+i, "java");  
         json.put("cccc"+i,str );  //值为一个数组
         list.add(json);  
        }  
        jsonobj.put("succList", list);  
        System.out.println(jsonobj.toString());  

 

运行结果:

     {"succList":

        [{"aaaa0":{"组合0":0,"组合1":1,"组合2":2},

         "bbbb0":"java","cccc0":["json","ajax","Jquery","javascript"]},

        {"aaaa1":{"组合0":0,"组合1":1,"组合2":2},

         "bbbb1":"java","cccc1":["json","ajax","Jquery","javascript"]},

        {"aaaa2":{"组合0":0,"组合1":1,"组合2":2},

         "bbbb2":"java","cccc2":["json","ajax","Jquery","javascript"]}

        ]}