JSON operation of Java (Gson)

Use the Gson package to manipulate JSON data.

Dependency Package: Gson-2.8.2.jar

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.2</version>
</dependency>

The code is as follows:

1  PackageJson.gson;2 3 Importjava.util.ArrayList;4 Importjava.util.List;5 ImportJava.util.Map;6 7 ImportCom.google.gson.Gson;8 ImportCom.google.gson.JsonArray;9 Importcom.google.gson.JsonElement;Ten ImportCom.google.gson.JsonParser; One ImportCom.google.gson.reflect.TypeToken; A  - /** - * Use Gson to manipulate JSON the * 1. Object entity class, LIST,MAP, etc. converted into----->jsonstring (for data transfer) - * 2.jsonString converted to-----> object entity class, List,map (parse the returned data) - * 3. I'm using the Gson-2.2.2.jar. -  * +  */ -  Public classJsonutil { +  A  at     Private StaticGson Gson =NULL; -  -     Static { -         if(Gson = =NULL) { -Gson =NewGson (); -         } in     } -  to  +     /** - * Turn Object object into JSON string (jsonstring) the * Boject can be a list or a bean (object type) *      * $      * @paramObjectPanax Notoginseng      */ -      Public StaticString gsonstring (Object object) { theString gsonstring =NULL; +         if(Gson! =NULL) { AGsonstring =Gson.tojson (object); the         } +         returngsonstring; -     } $  $  -     /** - * The import parameter is a JSON object the * Turn gsonobjectstring into a generic bean (entity Class) -      *Wuyi      * @paramgsonstring the      */ -      Public Static<T> T Gsontobean (String gsonstring, class<t>CLS) { WuT t =NULL; -         if(Gson! =NULL) { Aboutt =Gson.fromjson (gsonstring, CLS); $         } -         returnT; -     } -  A     /** + * The entry parameter here is a string of JSON array type the * jsonarraystring turn into List -      */ $      Public Static<T> list<t> jsonarraytolist (String json, class<t>CLS) { theGson Gson =NewGson (); thelist<t> list =NewArraylist<t>(); theJsonarray array =NewJsonparser (). Parse (JSON). Getasjsonarray (); the          for(Finaljsonelement Elem:array) { - List.add (Gson.fromjson (Elem, CLS)); in         } the         returnlist; the     } About  the  the     /** the * List is not required for generics + * jsonstring turns into list with map -      */ the      Public Static<T> list<map<string, t>>Gsontolistmap (String gsonstring) {BayiList List =NULL; the         if(Gson! =NULL) { theList =Gson.fromjson (gsonstring, -                     NewTypetoken<list>() { - }.gettype ()); the         } the         returnlist; the     } the  -     /** the * Request list is all map the * jsonstring turns into list with map the      */94      Public Static<T> list<map<string, t>>gsontolistmaps (String gsonstring) { thelist<map<string, t>> list =NULL; the         if(Gson! =NULL) { theList =Gson.fromjson (gsonstring,98                     NewTypetoken<list<map<string, t>>>() { About }.gettype ()); -         }101         returnlist;102     }103 104  the     /**106 * jsonstring turns into map.107      */108      Public Static<T> map<string, t>gsontomaps (String gsonstring) {109map<string, t> map =NULL; the         if(Gson! =NULL) {111Map = Gson.fromjson (gsonstring,NewTypetoken<map<string, t>>() { the }.gettype ());113         } the         returnmap; the     } the 117     /**118 * Map to Jsonstring, specifying the map type119      */ -      Public StaticString Maptojson (map<string, object>map) {121String str =NULL;122         if(Gson! =NULL) {123str =Gson.tojson (map);124         } the         returnstr;126     }127  -}

Test code:

1  PackageJson.gson;2 3 ImportBean. User;4 5  Public classTestgson {6 7     Private StaticUser User =NULL;8 9     Static {Tenuser =NewUser ("Tom", "the most street"); One     } A  -      Public Static voidMain (string[] args) { -String Jsonstr =jsonutil.gsonstring (user); the System.out.println (JSONSTR); -  -String jsonStr2 = "{\" name\ ": \" tom\ ", \" age\ ": 25,\" address\ ": \" Street\ "}"; -User User2 = Jsonutil.gsontobean (jsonStr2, user.class); + System.out.println (user2); -     } +}

Operation Result:

{"Name": "Tom", "Age": "Address": "The Street"}
User[name= ' Tom ', age=25, address= ' the street ']

JSON operation of Java (Gson)