Transform a String to JSONObject

Question

I am building an Android app that uses socket.IO to communicate with a server. On the socket I am receiving the following message:

{"id":"presenterResponse","response":"accepted","sdpAnswer":"v=0\r\no=- 3689503004 3689503004 IN IP4 0.0.0.0\r\ns=Kurento Media Server\r\nc=IN IP4 0.0.0.0\r\nt=0 0\r\na=msid-semantic: WMS ARDAMS\r\na=group:BUNDLE audio video\r\nm=audio 1 UDP/TLS/RTP/SAVPF 111 0\r\na=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=mid:audio\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=rtpmap:111 opus/48000/2\r\na=rtpmap:0 PCMU/8000\r\na=setup:active\r\na=sendrecv\r\na=rtcp-mux\r\na=fmtp:111 minptime=10; useinbandfec=1\r\na=maxptime:60\r\na=ssrc:3140217435 cname:user2918705367@host-8692fd1\r\na=ice-ufrag:aYIP\r\na=ice-pwd:sKftuHNg7pyX0FocNO0qh/\r\na=fingerprint:sha-256 33:B4:A7:4B:89:64:D2:54:AF:6B:FE:D4:5D:EF:4E:D6:AB:6F:11:B1:E7:31:87:D6:0D:22:3F:53:83:08:B7:73\r\nm=video 1 UDP/TLS/RTP/SAVPF 100\r\na=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=mid:video\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=rtpmap:100 VP8/90000\r\na=rtcp-fb:100 ccm fir\r\na=rtcp-fb:100 nack\r\na=rtcp-fb:100 nack pli\r\na=rtcp-fb:100 goog-remb\r\na=setup:active\r\na=sendrecv\r\na=rtcp-mux\r\na=ssrc:2322920152 cname:user2918705367@host-8692fd1\r\na=ice-ufrag:aYIP\r\na=ice-pwd:sKftuHNg7pyX0FocNO0qh/\r\na=fingerprint:sha-256 33:B4:A7:4B:89:64:D2:54:AF:6B:FE:D4:5D:EF:4E:D6:AB:6F:11:B1:E7:31:87:D6:0D:22:3F:53:83:08:B7:73\r\nm=application 0 DTLS/SCTP 5000\r\na=inactive\r\na=mid:data\r\na=ice-ufrag:igJW\r\na=ice-pwd:skfFXPCVLtGwABgXg9xsMO\r\na=fingerprint:sha-256 33:B4:A7:4B:89:64:D2:54:AF:6B:FE:D4:5D:EF:4E:D6:AB:6F:11:B1:E7:31:87:D6:0D:22:3F:53:83:08:B7:73\r\n"}

What I want to do now is to map this object on the following POJO class:

import org.webrtc.SessionDescription;

public class User {

    private String id;

    private String response;

    private String name;

    private String room;

    private String email;

    private String sdpOffer;

    private SessionDescription sdpAnswer;

    private String userType;

    public User(){};

    public SessionDescription getSdpAnswer() {
        return sdpAnswer;
    }

    public void setSdpAnswer(SessionDescription sdpAnswer) {
        this.sdpAnswer = sdpAnswer;
    }

    public String getResponse() {
        return response;
    }

    public void setResponse(String response) {
        this.response = response;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getUserType() {
        return userType;
    }

    public void setUserType(String userType) {
        this.userType = userType;
    }

    public String getSdpOffer() {
        return sdpOffer;
    }

    public void setSdpOffer(String sdpOffer) {
        this.sdpOffer = sdpOffer;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getRoom() {
        return room;
    }

    public void setRoom(String room) {
        this.room = room;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

So far I have tried to transform the message in a JSONObject JSONObject j = new JSONObject(message); and populate my own object from the JSONObject but it didn't work. How can I map the string on User class?

EDIT: the message comes over socket.IO from a Node.js server in this way: In the node server I send the message by send.("new message",JSON.stringfy("sdpAnswer":sdpAnswer)); On the android client I read it like:

LoginActivity.mSocket.on("new message", new Emitter.Listener() {

            @Override
            public void call(Object... args) {
                Log.i( TAG, "message back:received ");
             JSONObject j = new JSONObject(args[0]); // this throws an error
                   Object = new JSONObject(args[0].toString());
                    Log.i(TAG, "The received string is " + obj.toString()); //this throws java.lang.error can not convert from string to json object


}
)};

Possible duplicate of [How to parse JSON in Java](http://stackoverflow.com/questions/2591098/how-to-parse-json-in-java) — xes_p, Nov 30 '16 at 14:16
if you can use Jackson, watch https://www.mkyong.com/java/jackson-2-convert-java-object-to-from-json/ — vincent, Nov 30 '16 at 14:22
@lapusanmirel How did it not work? Anything showing up error wise? — xes_p, Nov 30 '16 at 14:23
I tried with Jackson i got some errors saying i cannot convert . I got errors can not convet to JSONObject from string — Player1, Nov 30 '16 at 14:28

score 0 · Answer 1 · answered Nov 30 '16 at 14:27

0

use Gson

    String jsonString = "{jsonstringhere}";
    User user= new Gson().fromJson(jsonString, User.class);

answered Nov 30 '16 at 14:27

Manza

3,427
4
36
57

score 0 · Answer 2 · answered Nov 30 '16 at 14:29

0

Use Gson library.

Add dependency to build.gradle file.

compile 'com.google.code.gson:gson:2.8.0'

And parse json to object:

Gson gson = new Gson();
User user= gson.fromJson(message, User.class);

answered Nov 30 '16 at 14:29

Guntars Ļuta

61
2
10

Already tried: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 2 – Player1 Nov 30 '16 at 14:38
private SessionDescription sdpAnswer; is object, but in your json it is a string – Guntars Ļuta Nov 30 '16 at 14:46
I have tried with object directly but it throws another error – Player1 Nov 30 '16 at 14:50

Transform a String to JSONObject

2 Answers2