Java使用falstjson包技巧

1.map转json

Map map = new HashMap();
map.put("a", "a");
map.put("b", "123");
JSONObject json = new JSONObject(map);


2.map转string

Map 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 map = (Map)json;


5.string转json

String str = "{\"username\":\"dsad\",\"qwewqe\":\"123\"}";
JSONObject json = JSONObject.parseObject(str);


6.json转map

private static Object json_to_map(String json)
{
Object array = JSONObject.parse(json);
if(array instanceof JSONArray){
List> list = new ArrayList>();
for (int i= 0;i<((JSONArray) array).size();i++)
{
JSONObject myjObject = ((JSONArray)array).getJSONObject(i);
Map ret1 = new HashMap();
for (Map.Entry entry : myjObject.entrySet()) {
if(isJson(entry.getValue().toString()))
{
ret1.put(entry.getKey(), json_to_map(entry.getValue().toString()));
}else{
log.info("JSOnObject=> key:" + entry.getKey().toString()+" value:"+entry.getValue());
ret1.put(entry.getKey(), entry.getValue());
}
}
list.add(ret1);
}
return list;
}
else if(array instanceof JSONObject){
Map ret = new HashMap();
for (Map.Entry entry : ((JSONObject)array).entrySet()) {
if(isJson(entry.getValue().toString()))
{
ret.put(entry.getKey(), json_to_map(entry.getValue().toString()));
}else{
log.info("JSOnObject=> key:" + entry.getKey().toString()+" value:"+entry.getValue());
ret.put(entry.getKey(), entry.getValue());
}
}
return ret;
}
return null;
}


判断是否为json串

/*
*字符串{},[]都是正确的json串
*/
public static boolean isJson(String str){
if (StringUtils.isBlank(str)){
return false;
}
try{
Object parse = JSON.parse(str);
if (parse instanceof JSONObject || parse instanceof JSONArray){
return true;
}
}catch (Exception e){
return false;
}
return false;
}


判断Object类型

Object ret = json_to_map(jsonmap);
log.info(ret == null ? "null" : ret instanceof HashMap ? "HashMap" : ret instanceof ArrayList ? "ArrayList" : ret.getClass().getTypeName());