一、场景复现

（1）代码

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import net.sf.json.JSONObject;public class C {public static void main(String[] args){JSONObject json = new JSONObject();json.put("str0","hello");json.put("str1","\"hello\"");json.put("str2"," \"hello \" ");json.put("str3","\"hello \"\n");json.put("jsonObj0","{\"count\":\"23\"}");json.put("jsonObj1","{\"count\":\"23\"}\n");json.put("jsonObj2"," {\"count\":\"23\"} ");json.put("jsonObj3","{\"count\":\"23\",size:2}");json.put("jsonObj4","{\"count\":\"23\",size:}");json.put("jsonArr0","[1,2]");json.put("jsonArr1"," [1,2]");json.put("jsonArr2","[1,2]\n");json.put("jsonArr3","\"[1,2]\"");json.put("jsonArr4","[1,2,-]");json.put("jsonArr5","[1,2,A]");System.out.println(format(json.toString()));}public static String format(String json) {JsonParser jsonParser = new JsonParser();JsonObject jsonObject = jsonParser.parse(json).getAsJsonObject();Gson gson = new GsonBuilder().setPrettyPrinting().create();return gson.toJson(jsonObject);}}

    <dependency><groupId>com.google.code.gson</groupId><artifactId>gson</artifactId><version>2.8.5</version></dependency>

（2）输出

json-lib-2.3输出：

<dependency><groupId>net.sf.json-lib</groupId><artifactId>json-lib</artifactId><version>2.3</version><classifier>jdk15</classifier>
</dependency>

{"str0": "hello","str1": "hello","str2": " \"hello \" ","str3": "\"hello \"\n","jsonObj0": {"count": "23"},"jsonObj1": "{\"count\":\"23\"}\n","jsonObj2": " {\"count\":\"23\"} ","jsonObj3": {"count": "23","size": 2},"jsonObj4": "{\"count\":\"23\",size:}","jsonArr0": [1,2],"jsonArr1": " [1,2]","jsonArr2": "[1,2]\n","jsonArr3": "[1,2]","jsonArr4": [1,2,"-"],"jsonArr5": "[1,2,A]"
}

json-lib-2.4输出：

<dependency><groupId>net.sf.json-lib</groupId><artifactId>json-lib</artifactId><version>2.4</version><classifier>jdk15</classifier>
</dependency>

{"str0": "hello","str1": "\"hello\"","str2": " \"hello \" ","str3": "\"hello \"\n","jsonObj0": {"count": "23"},"jsonObj1": "{\"count\":\"23\"}\n","jsonObj2": " {\"count\":\"23\"} ","jsonObj3": {"count": "23","as": 2},"jsonObj4": "{\"count\":\"23\",as:}","jsonArr0": [1,2],"jsonArr1": " [1,2]","jsonArr2": "[1,2]\n","jsonArr3": "[1,2]","jsonArr4": [1,2,"-"],"jsonArr5": "[1,2,A]"
}

（3）异常现象

字符串"\"xx\""转换成"xx"，"{\"key\":value}"转成{"key":value}对象，"[value,vlaue]""转成[value,vlaue]对象

json-lib版本不同：json-lib-1.3把"\"xx\""转换成"xx"，"{\"key\":value}"转成{"key":value}对象，"[value,vlaue]""转成[value,vlaue]对象

json-lib-1.4的"\"xx\""不转换，而"{\"key\":value}"转成{"key":value}对象，"[value,vlaue]""转成[value,vlaue]对象

 

二、原因

json-lib与Gson等其他JSON库不一样，会默认将json字符串（包含双引号字符串）转换json对象。