EDITED:
I am trying to convert the JSON responses that i am getting from REST API service to objects inside my application. I use Jersey to perform “GET” requests to REST the service.
Lets say that i have the following two API calls, each one having its corresponding JSON response as:
First call: Get a specific myEntity object with its code value: https://www.test.com/webservice/entity/get?code=BOBS-JC6L (GET)
Response:
{
"isOk": 1,
"isAuthError": 0,
"error": false,
"myEntity":{
"id": "123",
"code": "BOBS-JC6L",
"type": "ZZZ",
"value": "15.00",
}
}
Second call: Get all myEntity objects: https://www.test.com/webservice/entity/get-all (GET)
Response:
{
"isOk": 1,
"isAuthError": 0,
"error": false,
"myEntities": [
{
"id": "123",
"code": "BOBS-JC6L",
"type": "ZZZ",
"value": "15.00",
},
{
"id": "456",
"code": "BOBS-JC7L",
"type": "CCC",
"value": "32.00",
}
{...}
]
}
So in both cases the fundamental object (of type MyEntity) is included in JSON as nested element(s). I am trying to map JSON structure into POJO objects.
So i have created the following POJO classes:
MyEntity POJO (this is the fundamental nested element(s) class):
import java.math.BigDecimal;
import java.time.LocalDate;
import java.util.Date;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
public class MyEntity {
private int id;
private String code;
private String type;
private BigDecimal value;
public MyEntity(){
}
public MyEntity(String code, String type, BigDecimal value){
this.code = code;
this.type = type;
this.value = value;
}
....
}
Then there is a class for the first API call response (we get a single MyEntity object):
@XmlRootElement
public class GetSingleMyEntityResponse {
private int isOk;
private int isAuthError;
private boolean error;
private MyEntity myEntity;
...
}
And another class for the second API call response (we get multiple nested MyEntity objects):
@XmlRootElement
public class GetMultipleMyEntityResponse {
private int isOk;
private int isAuthError;
private boolean error;
private List<MyEntity> myEntities;
...
}
In my code i first try to get a single myEntity object, calling: https://www.test.com/webservice/entity/get?code=BOBS-JC6L
try {
ClientConfig clientConfig = new DefaultClientConfig();
Client client = Client.create(clientConfig);
WebResource webResource1 = client
.resource("https://www.test.com/webservice/entity/get?code=MESM-ZB2NEJ");
Builder builder = webResource1.accept(MediaType.APPLICATION_JSON) //
.header("content-type", MediaType.APPLICATION_JSON);
ClientResponse response = builder.get(ClientResponse.class);
// Status 200 is successful.
if (response.getStatus() != 200) {
System.out.println("Failed with HTTP Error code: " + response.getStatus());
String error = response.getEntity(String.class);
System.out.println("Error: " + error);
return;
}
System.out.println("\n\nOutput from Server .... \n");
GetSingleMyEntityResponse vResp = (GetSingleMyEntityResponse) response.getEntity(GetSingleMyEntityResponse.class);
MyEntity v = vResp.getMyEntity();
if(v.getId()>0) {
System.out.println("Id .... " + v.getId());
System.out.println("Code .... " + v.getCode());
System.out.println("Type .... " + v.getType());
System.out.println("Value .... " + v.getValue());
}
} catch (Exception e) {
e.printStackTrace();
}
This works and i am able to get MyEntity object:
Output from Server ....
Id .... 123
Code .... BOBS-JC6L
Type .... ZZZ
Value .... 15.00
I am also trying to map multiple MyEntity objects from: https://www.test.com/webservice/entity/get-all
try {
Client client = Client.create();
WebResource webResource = client
.resource("https://www.test.com/webservice/entity/get-all");
ClientResponse response = webResource.accept("application/json")
.get(ClientResponse.class);
if (response.getStatus() != 200) {
throw new RuntimeException("Failed : HTTP error code : "
+ response.getStatus());
}
String output = response.getEntity(String.class);
GetMultipleMyEntityResponse vResp = (GetMultipleMyEntityResponse) response.getEntity(GetMultipleMyEntityResponse.class);
List<MyEntity> vRespList = new ArrayList<>();
vRespList = vResp.getMyEntities();
if(vRespList.size()>0) {
for(MyEntity v:vRespList) {
System.out.println("Id .... " + v.getId());
System.out.println("Code .... " + v.getCode());
System.out.println("Type .... " + v.getType());
System.out.println("Value .... " + v.getValue());
}
}
} catch (Exception e) {
e.printStackTrace();
}
But is seems that the GetMultipleMyEntityResponse POJO class is not working for it, and i am getting:
j
avax.ws.rs.WebApplicationException: HTTP 400 Bad Request
at com.sun.jersey.core.provider.jaxb.AbstractRootElementProvider.readFrom(AbstractRootElementProvider.java:113)
at com.sun.jersey.api.client.ClientResponse.getEntity(ClientResponse.java:553)
at com.sun.jersey.api.client.ClientResponse.getEntity(ClientResponse.java:506)
at com.mspos.mesmo.JerseyClientGet.main(JerseyClientGet.java:97)
Caused by: javax.xml.bind.UnmarshalException: Error creating JSON-based XMLStreamReader
- with linked exception:
[javax.xml.stream.XMLStreamException: java.io.IOException: stream is closed]
at com.sun.jersey.json.impl.BaseJSONUnmarshaller.createXmlStreamReader(BaseJSONUnmarshaller.java:116)
at com.sun.jersey.json.impl.BaseJSONUnmarshaller.unmarshalJAXBElementFromJSON(BaseJSONUnmarshaller.java:108)
at com.sun.jersey.json.impl.BaseJSONUnmarshaller.unmarshalFromJSON(BaseJSONUnmarshaller.java:97)
at com.sun.jersey.json.impl.provider.entity.JSONRootElementProvider.readFrom(JSONRootElementProvider.java:125)
at com.sun.jersey.core.provider.jaxb.AbstractRootElementProvider.readFrom(AbstractRootElementProvider.java:111)
... 3 more
Caused by: javax.xml.stream.XMLStreamException: java.io.IOException: stream is closed
at com.sun.jersey.json.impl.Stax2JsonFactory.ensureNonEmptyReader(Stax2JsonFactory.java:173)
at com.sun.jersey.json.impl.Stax2JsonFactory.createReader(Stax2JsonFactory.java:117)
at com.sun.jersey.json.impl.Stax2JsonFactory.createReader(Stax2JsonFactory.java:111)
at com.sun.jersey.json.impl.BaseJSONUnmarshaller.createXmlStreamReader(BaseJSONUnmarshaller.java:113)
... 7 more
Caused by: java.io.IOException: stream is closed
at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.ensureOpen(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(Unknown Source)
at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
at sun.nio.cs.StreamDecoder.implRead(Unknown Source)
at sun.nio.cs.StreamDecoder.read(Unknown Source)
at java.io.InputStreamReader.read(Unknown Source)
at java.io.BufferedReader.fill(Unknown Source)
at java.io.BufferedReader.read(Unknown Source)
at com.sun.jersey.json.impl.Stax2JsonFactory.ensureNonEmptyReader(Stax2JsonFactory.java:167)
... 10 more
Any ideas of what am i missing?
You're calling response.getEntity() twice. Call it only once.