java - How to ignore a specific field while parsing a JSON into map -

i want parse below json pojo. using jackson parse json.

{   "totalsize": 4,   "done": true,   "records": [     {       "attributes": {         "type": "oppor",         "url": "/service/oppor/456"       },       "accountid": "123",       "id": "456",       "proposalid": "103"     }   ] } 

in above json, fields "totalsize", "done", "records" , "attributes" known fields. whereas, "accountid", "id" , "proposalid" unknown fields. , in above json, don't need "attributes" part of bean object.

and here equivalent bean class json

public class result {     private int totalsize;     private boolean done;     private list<map<string, string>> records;      public int gettotalsize() {         return totalsize;     }      public void settotalsize(int totalsize) {         this.totalsize = totalsize;     }      public boolean isdone() {         return done;     }      public void setdone(boolean done) {         this.done = done;     }      public list<map<string,string>> getrecords() {         return records;     }      public void setrecords(list<map<string, string>> records) {         this.records = records;     }  } 

hence there unknown fields in records element used list results element in bean. here in map, don't want field "attributes". how can ignore while parsing? , below exception getting attributes not string element.

com.fasterxml.jackson.databind.jsonmappingexception: can not deserialize instance of java.lang.string out of start_object token  @ [source: [b@66fdec9; line: 1, column: 40] (through reference chain: com.sample.json.result["records"])     @ com.fasterxml.jackson.databind.jsonmappingexception.from(jsonmappingexception.java:164)     @ com.fasterxml.jackson.databind.deserializationcontext.mappingexception(deserializationcontext.java:691)     @ com.fasterxml.jackson.databind.deser.std.stringdeserializer.deserialize(stringdeserializer.java:46)     @ com.fasterxml.jackson.databind.deser.std.stringdeserializer.deserialize(stringdeserializer.java:11)     @ com.fasterxml.jackson.databind.deser.std.mapdeserializer._readandbindstringmap(mapdeserializer.java:430)     @ com.fasterxml.jackson.databind.deser.std.mapdeserializer.deserialize(mapdeserializer.java:312)     @ com.fasterxml.jackson.databind.deser.std.mapdeserializer.deserialize(mapdeserializer.java:26)     @ com.fasterxml.jackson.databind.deser.std.collectiondeserializer.deserialize(collectiondeserializer.java:227)     @ com.fasterxml.jackson.databind.deser.std.collectiondeserializer.deserialize(collectiondeserializer.java:204)     @ com.fasterxml.jackson.databind.deser.std.collectiondeserializer.deserialize(collectiondeserializer.java:23) 

update 2015/08/29:

as have commented

i achieved dynamic field support parsing json map. ignoring bad json element pending

i suggest should process original jsonobject remove "attributes" element it.

original jsonobject, example:

{   "totalsize": 4,   "done": true,   "records": [     {       "attributes": {         "type": "oppor",         "url": "/service/oppor/456"       },       "accountid": "123",       "id": "456",       "proposalid": "103"     }   ] } 

after process, new jsonobject following:

{     "records": {         "accountid": "123",         "id": "456",         "proposalid": "103"     },     "totalsize": 4,     "done": true } 

use code following:

        jsonobject jsonobject;         try {                         jsonobject = new jsonobject(jsonstring1);             jsonarray jsonarray = new jsonarray(jsonobject.get("records").tostring());                         jsonobject jsonobject1 = jsonarray.getjsonobject(0);             jsonobject1.remove("attributes");             jsonobject.put("records", jsonobject1);         } catch (jsonexception e) {             e.printstacktrace();         } 

then, use own code achieved dynamic field support parsing json map.

end of update 2015/08/29

i suggest use gson , transient in case

like this

        string jsonstring1 = "{\n" +                 "  \"totalsize\": 4,\n" +                 "  \"done\": true,\n" +                 "  \"records\": [\n" +                 "    {\n" +                 "      \"attributes\": {\n" +                 "        \"type\": \"oppor\",\n" +                 "        \"url\": \"/service/oppor/456\"\n" +                 "      },\n" +                 "      \"accountid\": \"123\",\n" +                 "      \"id\": \"456\",\n" +                 "      \"proposalid\": \"103\"\n" +                 "    }\n" +                 "  ]\n" +                 "}";          gson gson = new gson();         result result1 = gson.fromjson(jsonstring1, result.class); 

your classes, pay attention transient:

public class result {     private int totalsize;     private boolean done;     private list<record> records; }  public class record {     private transient map<string, string> attributes;     private int accountid;     private int id;     private int proposalid; } 

you result:

p/s: tested in android studio :)

update:

      string jsonstring1 = "{\n" +                 "  \"totalsize\": 4,\n" +                 "  \"done\": true,\n" +                 "  \"records\": [\n" +                 "    {\n" +                 "      \"attributes\": {\n" +                 "        \"type\": \"oppor\",\n" +                 "        \"url\": \"/service/oppor/456\"\n" +                 "      },\n" +                 "      \"accountid\": \"123\",\n" +                 "      \"id\": \"456\",\n" +                 "      \"proposalid\": \"103\"\n" +                 "    }\n" +                 "  ]\n" +                 "}";         gson gson = new gson();         object object = gson.fromjson(jsonstring1, object.class);         map<string, string> stringmap = (map<string, string>) object;         result myresult = new result();         iterator entries = stringmap.entryset().iterator();         while (entries.hasnext()) {             map.entry entry = (map.entry) entries.next();             string key = entry.getkey().tostring();             string value = entry.getvalue().tostring();             switch (key) {                 case "totalsize":                     myresult.totalsize = (int) double.parsedouble(entry.getvalue().tostring());                     break;                 case "done":                     myresult.done = boolean.valueof(entry.getvalue().tostring());                     break;                 case "records":                     try{                         object object1 = entry.getvalue();                         list<object> objectlist = (list<object>) object1;                         map<string, object> stringmap2 = (map<string, object>) objectlist.get(0);                         map<string, string> recordmap = new hashmap<>();                         iterator entries2 = stringmap2.entryset().iterator();                         while (entries2.hasnext()) {                             map.entry entry2 = (map.entry) entries2.next();                             string key2 = entry2.getkey().tostring();                             string value2 = entry2.getvalue().tostring();                             if (!"attributes".equals(key2)) {                                 recordmap.put(key2, value2);                             }                             entries2.remove();                         }                         myresult.records = recordmap;                     } catch (exception e) {                         e.printstacktrace();                     }                     break;             }             entries.remove();         } 

classes:

public class result {     private int totalsize;     private boolean done;     private map<string, string> records;         } 

debug result: