Map和JSON之间的转化

1 添加依赖

        <dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.47</version></dependency>

2 测试

2.1 Map转JSON

    //1.map转json@Testpublic void testJson01(){//1.Map转JSONMap<String,Object> map=new HashMap<>();map.put("A","a");map.put("B","b");JSONObject jsonObject = new JSONObject(map);System.out.println(jsonObject);}

2.2 Map转String

    //2.map转Spring@Testpublic void testJson02(){Map<String,Object> map=new HashMap<>();map.put("A","a");String s = JSONObject.toJSONString(map);System.out.println(s);}

2.3 JSON转String

    //3.JSON转String@Testpublic void testJSON03(){JSONObject json=new JSONObject();json.put("A","A");json.put("B","B");String s = json.toJSONString();System.out.println(s);}

2.4 JSON转Map

    //4.JSON转map@Testpublic void testJSON04(){JSONObject jsonObject=new JSONObject();jsonObject.put("A","a");jsonObject.put("B","b");Map<String,Object> map= (Map<String,Object>)jsonObject;for(Map.Entry<String,Object> entry:map.entrySet()){System.out.println(entry.getKey()+"--"+entry.getValue());}}

2.5 String转JSON

    //5.String转json@Testpublic void testJSON05(){String str="{\"username\":\"abc\",\"pwd\":\"123\"}";JSONObject json = JSONObject.parseObject(str);Object username = json.get("username");System.out.println(username);Object pwd = json.get("pwd");System.out.println(pwd);}

2.6List<String,Objet>转成jsonArray

	List<Map<String,Object>> list=new LinkedList<>();for(int i=0;i<10;i++){Map<String,Object>  map=new HashMap<>();map.put("a"+i,"a");list.add(map);}JSONArray jsonArray= (JSONArray) JSONArray.toJSON(list);System.out.println(jsonArray.size());