Common operations for Fastjson

Reprint: https://www.cnblogs.com/Ming8006/p/6944954.html

Common operations include the following:

1. The interchange of objects with (Jsonobject or Jsonarray) and string
2. How string is converted to (Jsonobject or jsonarray) to maintain order
3. Use of Eval
4. How to save a value of NULL (Jsonobject or Jsonarray) when converting to string

Code:

Package Demo.sample1;import Com.alibaba.fastjson.json;import Com.alibaba.fastjson.jsonpath;import    Com.alibaba.fastjson.parser.feature;import Com.alibaba.fastjson.serializer.serializerfeature;public class Sample {        public static void Main (string[] args) {Group group = Generategroup (); String ss= "{\" id\ ": 1.1,\" name\ ": \" admin\ ", \" users\ ": [{\" id\ ": 2.2,\" name\ ": \" guest\ "},{\" id\ ": 3.3,\" name\ ": \"                Root\ "}]}";                Group Groupwithnull=generategroupwithnull ();        Basicobjecttostringcompare ();        Jsonobjecttostringcompare (ss);        Njsonobjecttostringcompare (group);                Jsonstringsequence (Group, SS);        Jsoneval (SS, "$.users");            Dealwithnulltostringstring (Groupwithnull); } public static void Basicobjecttostringcompare () {System.out.println ("----------Primitive type toString () ToJSON        String () Comparison:----------");        System.out.println ("Zifuchuan"); System.out.println (json.tojsonstring ("Zifuchuan"));        System.out.println (TRUE);        System.out.println (Json.tojsonstring (true));        SYSTEM.OUT.PRINTLN (1.1);    SYSTEM.OUT.PRINTLN (json.tojsonstring (1.1)); } public static string Njsonobjecttostringcompare (group group) {String jsonstring = json.tojsonstring (group        );        SYSTEM.OUT.PRINTLN ("----------Non-Jsonobject toString () tojsonstring () Comparison:----------");        System.out.println (Group.tostring ());        System.out.println (json.tojsonstring (group));    return jsonstring;        } public static string Jsonobjecttostringcompare (String ss) {Object o=json.parse (Ss,feature.orderedfield);        System.out.println ("----------jsonobject toString () tojsonstring () Comparison:----------");        System.out.println (O.tostring ());        System.out.println (json.tojsonstring (o));    return SS; The public static void Jsonstringsequence (group group, String jsonstring) {System.out.println ("----------has        ----------"); Object O=jSon.parse (jsonstring);                System.out.println (O.tostring ());;        Object O1=json.parse (Jsonstring,feature.orderedfield);                System.out.println (O1.tostring ());        Object O2 = Json.tojson (group);    System.out.println (O2.tostring ()); The public static void Jsoneval (String ss,string jsonPath) {System.out.println ("----------Json Eval:-------                ---");        Object O3=jsonpath.eval (Json.parse (Ss,feature.orderedfield), JSONPath);    System.out.println (O3.tostring ());  } public static void Dealwithnulltostringstring (Group groupwithnull) {System.out.println ("----------Jsonobject        With null Emlement:----------");        System.out.println (json.tojsonstring (groupwithnull));    System.out.println (json.tojsonstring (Groupwithnull,serializerfeature.writemapnullvalue));        } private static Group Generategroup () {Group group = new Group ();        Group.setid (1.1);        Group.setname ("admin"); User GUEStuser = new User ();        Guestuser.setid (2.2);        Guestuser.setname ("Guest");        User Rootuser = new user ();        Rootuser.setid (3.3);        Rootuser.setname ("root");        Group.adduser (Guestuser);        Group.adduser (Rootuser);    return group;        } private static Group Generategroupwithnull () {Group group = new Group ();        Group.setid (1.1);        Group.setname ("");        User GuestUser1 = new user ();        Guestuser1.setid (NULL);        Guestuser1.setname ("Guest");        User GuestUser2 = new user ();                Guestuser2.setid (3.3);                User GuestUser3 = new user ();        Group.adduser (GuestUser1);        Group.adduser (GUESTUSER2);        Group.adduser (GUESTUSER3);    return group; }}

Results:

----------Primitive Type toString () tojsonstring () Comparison:----------Zifuchuan"Zifuchuan"truetrue1.11.1----------jsonobject toString () tojsonstring () Comparison:----------{"id": 1.1, "name": "Admin", "users": [{"id": 2.2, "name": "Guest"},{"id": 3.3, "name": "Root"}]}{"id": 1.1, "name": "Admin", "users": [{"id": 2.2, "name": "Guest"},{"id": 3.3, "name": "Root"}]}----------Non-Jsonobject toString () tojsonstring () Comparison:----------[Email protected]{"id": 1.1, "name": "Admin", "users": [{"id": 2.2, "name": "Guest"},{"id": 3.3, "name": "Root"}]}----------is ordered:----------{"Name": "admin", "id": 1.1, "users": [{"Name": "Guest", "id": 2.2},{"name": "Root", "id": 3.3}]}{"id": 1.1, "name": "Admin", "users": [{"id": 2.2, "name": "Guest"},{"id": 3.3, "name": "Root"}]}{"Name": "admin", "id": 1.1, "users": [{"Name": "Guest", "id": 2.2},{"name": "Root", "id": 3.3}]}----------Json Eval:----------[{"id": 2.2, "name": "Guest"},{"id": 3.3, "name": "Root"}]----------Jsonobject withNULLEmlement:----------{"id": 1.1, "name": "", "users": [{"Name": "Guest"},{"id": 3.3},{}]}{"id": 1.1, "name": "", "users": [{"id":NULL, "name": "Guest"},{"id": 3.3, "name":NULL},{"id":NULL, "name":NULL}]}

Reference:

[1] Introducing JSON

http://www.json.org/

[2] Fastjson Tutorial

Https://www.w3cschool.cn/fastjson/%20

Common operations for Fastjson