项目中出现了这样一个问题，当一个Map被转成Json字符串后，由于业务需求，会将Map转为JsonObject，添加元素后，又转成Json字符串，最后再被包装到另一个Map里，被转成Json字符串发送给APP端，这个时候APP端反应结果中带有“\”转义字符，无法解析。
简化一下问题：
当一个Map被转成Json字符串后，被添加到另一个Map中，如果这个新的Map需要转成Json字符串格式，那么转化后，内部的这个Map转成的Json字符串，都会被加上“\”转义字符。
简单的模拟一下：
public static void main(String[] args) {HashMap<String, Object> param = new HashMap<>();param.put("userId", 66666);param.put("username", "XXXX");HashMap<String, String> pushMap = new HashMap<>();pushMap.put("testKey01", "value01");pushMap.put("testKey02", "value02");param.put("pushJson", JSON.toJSONString(pushMap));String pushJson = JSON.toJSONString(param);System.out.println(pushJson);}
格式化一下结果：
{"pushJson":"{\"testKey01\":\"value01\",\"testKey02\":\"value02\"}","userId":66666,"username":"XXXX"}
延伸测试一下，如果用JSONObject转Json字符串会不会有问题：
public static void main(String[] args) {HashMap<String, Object> param = new HashMap<>();param.put("userId", 66666);param.put("username", "XXXX");// HashMap<String, String> pushMap = new HashMap<>();// pushMap.put("testKey01", "value01");// pushMap.put("testKey02", "value02");JSONObject pushObject = new JSONObject();pushObject.put("testKey01", "value01");pushObject.put("testKey02", "value02");param.put("pushJson", pushObject.toJSONString());String pushJson = JSON.toJSONString(param);System.out.println(pushJson);}
格式化一下结果：
{"pushJson":"{\"testKey01\":\"value01\",\"testKey02\":\"value02\"}","userId":66666,"username":"XXXX"}
用原本的Map和JSONObject：
public static void main(String[] args) {HashMap<String, Object> param = new HashMap<>();param.put("userId", 66666);param.put("username", "XXXX");HashMap<String, String> pushMap = new HashMap<>();pushMap.put("testKey01", "value01");pushMap.put("testKey02", "value02");JSONObject pushObject = new JSONObject();pushObject.put("testKey01", "value01");pushObject.put("testKey02", "value02");param.put("pushJson", pushMap);String pushJson1 = JSON.toJSONString(param);System.out.println(pushJson1);param.put("pushJson", pushObject);String pushJson2 = JSON.toJSONString(param);System.out.println(pushJson2);}
结果：
{"pushJson":{"testKey01":"value01","testKey02":"value02"},"userId":66666,"username":"XXXX"}{"pushJson":{"testKey01":"value01","testKey02":"value02"},"userId":66666,"username":"XXXX"}
这样就不带转义字符了
而项目中，我是采用将JSON字符串转回Map，然后添加到新的Map中，再转成JSON字符串的方式解决这个问题的：
HashMap<String, Object> pushApp = new HashMap<>();pushApp.put("userId", userList);pushApp.put("pushType", pushType);pushApp.put("pushJson", JSON.parseObject(message, HashMap.class));String pushJson = JSON.toJSONString(pushApp);
当然上面带“\”转义字符的结果也是有办法解析的：
public static void main(String[] args) {HashMap<String, Object> param = new HashMap<>();param.put("userId", 66666);param.put("username", "XXXX");HashMap<String, String> pushMap = new HashMap<>();pushMap.put("testKey01", "value01");pushMap.put("testKey02", "value02");param.put("pushJson", JSON.toJSONString(pushMap));String pushJson = JSON.toJSONString(param);System.out.println(pushJson);JSONObject jsonObject = JSONObject.parseObject(pushJson);JSONObject jsonData = jsonObject.getJSONObject("pushJson");System.out.println("pushJson: " + jsonData);String value1 = jsonData.getString("testKey01");System.out.println("key: testKey01 value: " + value1);}
结果：
{"pushJson":"{\"testKey01\":\"value01\",\"testKey02\":\"value02\"}","userId":66666,"username":"XXXX"}pushJson: {"testKey01":"value01","testKey02":"value02"}key: testKey01 value: value01
-09-12
HashMap jsonMap = JSON.parseObject(pushJson,HashMap.class);String resultJson = String.valueOf(jsonMap.get("pushJson"));System.out.println(resultJson);
反解析的时候，还是可以正常解析出来，不需要转成jsonObject也可以
{"pushJson":"{\"testKey01\":\"value01\",\"testKey02\":\"value02\"}","userId":66666,"username":"XXXX"}{"testKey01":"value01","testKey02":"value02"}
