第一种alibaba falstjson：
1.Map转JSON
Map<String, Object> map = new HashMap<String, Object>();map.put("a", "a");map.put("b", "123");JSONObject json = new JSONObject(map);
2.map转string
Map<String, Object> map = new HashMap<>();map.put("a", "b");String s = JSONObject.toJSONString(map);
3.JSON转String
JSONObject json = new JSONObject();json.put("c", "v");json.put("z", "123n);json.toJSONString();
4.JSON转Map
JSONObject json = new JSONObject();json.put("ccc", "321");json.put("bbb", "123");Map<String, Object> map = (Map<String, Object>)json;
5.String转JSON
String str = "{\"username\":\"dsad\",\"qwewqe\":\"123\"}";JSONObject json = JSONObject.parseObject(str);
2 google
maven坐标
<!-- /artifact/com.google.code.gson/gson --><dependency><groupId>com.google.code.gson</groupId><artifactId>gson</artifactId><version>2.3.1</version></dependency>
//Map转换成JSON
Map<String,String> map = new HashMap<String,String>(); map.put("a","aaa"); map.put("b","bbb"); map.put("c","ccc"); String json=JSON.toJSONString(map); System.out.println(json);//输出{"a":"aaa","b":"bbb","c":"ccc"}
//JSON转换成Map
Map map1 = JSON.parseObject(json);System.out.println(map1.get("a"));for (Object mapData : map.entrySet()) {Map.Entry<String,String> entry = (Map.Entry<String,String>)mapData;System.out.println(entry.getKey()+"--->"+entry.getValue());}/*输出b--->bbbc--->ccca--->aaa*/
map中含有对象Map -> JSON
//Map -> JSONMap<String,Bar> map = new HashMap<String, Bar>(); map.put("a",new Bar()); map.put("b",new Bar()); map.put("c",new Bar()); String json = JSON.toJSONString(map,true); System.out.println(json); /*输出{"a":{"barAge":383687382,"barDate":149494588,"barName":"name_1689176802"},"b":{"barAge":-100528778,"barDate":149494588,"barName":"name_-878176366"},"c":{"barAge":-344075192,"barDate":149494588,"barName":"name_-1710740534"}}*/
//JSON -> Map
Map<String,Bar> map1 = (Map<String,Bar>)JSON.parse(json); for (String key : map1.keySet()) { System.out.println(key+":"+map1.get(key)); } /*输出b:{"barAge":-100528778,"barDate":149494588,"barName":"name_-878176366"}c:{"barAge":-344075192,"barDate":149494588,"barName":"name_-1710740534"}a:{"barAge":383687382,"barDate":149494588,"barName":"name_1689176802"}*/
-------------------===-------------------------附--MAP的ASCII排序-----------------------===------------------------
StringBuilder sb = new StringBuilder();List<String> keys = new ArrayList<String>(map.keySet());Collections.sort(keys);//排序。for(String k : keys){String v = params.get(k);if(StringUtils.isNotEmpty(v)){sb.append(v);}}//return MD5.toMD5(sb+key, "UTF-8");这个就不用看了~~~
