java - JSON has unique keys for all objects, how to convert to POJO using GSON? -

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• dealing randomly generated , inconsistent json field/key names using gson 2 answers

i have particular situation retrieving list of objects have unique ids keys, , have nested objects have own unique ids.

i using gson create pojos when creating model classes these objects need serialize unique key values, not solution.

i have attached image give better idea of talking about:

i want gson create list of nestedobject1 self contain list of nestedobject2. problem key value unique each type of nestedobject

i thinking of doing so:

objects.java

public class objects {      @serializedname("objects")     private list<nestedobject1> mnestedobjects1;     public list<nestedobject1> getnestedobjects1() {         return mnestedobjects1;     }  } 

nestedobjects1.java

public class nestedobject1 {      @serializedname("what-to-put-here?")     private string mid;     public string getid() {         return mid;     }      @serializedname("what-to-put-here?")     private list<nestedobject2> mnestedobjects2;     public list<nestedobject2> getnestedobjects2() {         return mnestedobjects2;     }  } 

nestedobject2

public class nestedobject2 {      // same deal here?  } 

any suggestions on how tackle this?

edit: sample json output

"objects" : { "-jrevnezhqv73jxku0-u" : {   "-jrevobezaysrrttngp-" : {     "started" : true   },   "-jrevqanythhjrimgr-r" : {     "started" : true   } }, "-jrf0_ywy_nmrmrob3qp" : {   "-jrf0lwrsa5kmu6snc7z" : {     "started" : true   },   "-jrf1txlofd2w4wn8q4n" : {     "started" : true   },   "-jrf2skhdmmt9wn3wkvs" : {     "started" : true   } }, "-jrf3xskpvo2wmzf1osb" : {   "-jrf3zywyxuz0rdoovna" : {     "started" : true   },   "-jrf4d-ceslhqbbzdft1" : {     "started" : true   },   "-jrf5gufddqfgjw8ayrb" : {     "started" : true   } }, } 

as names not same, can't use neither annotation or have field same name in java class.

what suggest implement custom deserializer shouldn't have care these key-values.

assuming proper constructors here's how implement deserializer objects class (by way it's bad name there class named objects in jdk).

class objectsdeserializer implements jsondeserializer<objects> {     @override     public objects deserialize(jsonelement json, type typeoft, jsondeserializationcontext context) throws jsonparseexception {         jsonobject jsonobject = json.getasjsonobject().getasjsonobject("objects");         list<nestedobject1> list = new arraylist<>();         for(map.entry<string, jsonelement> entry : jsonobject.entryset()) {             list<nestedobject2> nestedobject2list = new arraylist<>();             //here deserialize each nestedobject2 , put in list             list.add(new nestedobject1(entry.getkey(), nestedobject2list));         }         return new objects(list);     } } 

then register deserializers in gson parser:

gson gson = new gsonbuilder()     .registertypeadapter(objects.class, new objectsdeserializer())     .registertypeadapter(nestedobject2.class, new nestedobject2deserializer())     .create();  objects o = gson.fromjson(new filereader(new file("file.json")), objects.class); 

which outputs:

objects{mnestedobjects1=     nestedobject1{mid='-jrevnezhqv73jxku0-u', mnestedobjects2=[]}     nestedobject1{mid='-jrf0_ywy_nmrmrob3qp', mnestedobjects2=[]}     nestedobject1{mid='-jrf3xskpvo2wmzf1osb', mnestedobjects2=[]} } 

you'd need define custom deserializer nestedobject2 class, here fill empty list, guess able it's same principle.

hope helps! :-)