Apache HttpClient - REST API: Issue in converting response to customized object which is put as SerializableEntity - rest

Question

I am using Apache HttpClient to put/get customized object using REST APIs. Below is the sample code. My putObject() method works fine and I could serialize Person object and put properly. However, while getting the object, I got below error:
Exception in thread "main" java.lang.ClassCastException: [B cannot be cast to Person at MyTest.demoGetRESTAPI(MyTest.java:88) at MyTest.main(MyTest.java:21)
Seems the code to build Person object out of response entity is not correct
HttpEntity httpEntity = response.getEntity();
byte[] resultByteArray = EntityUtils.toByteArray(httpEntity);
Person person = (Person)SerializationUtils.deserialize(resultByteArray);
Am I doing somthing wrong while getting byte[] array and converting to Person object. Please help me out to solve this issue.
Complete Example Program:
import java.io.Serializable;
import org.apache.commons.lang.SerializationUtils;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.entity.SerializableEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
public class MyTest {
public static void main(String[] args) throws Exception {
putObject();
getObject();
}
public static void putObject() throws Exception
{
HttpClient httpClient = new DefaultHttpClient();
Person person = new Person();
person.setName("Narendra");
person.setId("1");
try
{
//Define a postRequest request
HttpPut putRequest = new HttpPut("http://localhost:9084/ehcache-server/rest/screeningInstance/2221");
//Set the API media type in http content-type header
putRequest.addHeader("content-type", "application/x-java-serialized-object");
//Set the request put body
SerializableEntity personSEntity = new SerializableEntity(SerializationUtils.serialize(person));
putRequest.setEntity(personSEntity);
//Send the request; It will immediately return the response in HttpResponse object if any
HttpResponse response = httpClient.execute(putRequest);
//verify the valid error code first
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != 201)
{
throw new RuntimeException("Failed with HTTP error code : " + statusCode);
}
}
finally
{
//Important: Close the connect
httpClient.getConnectionManager().shutdown();
}
}
public static void getObject() throws Exception
{
DefaultHttpClient httpClient = new DefaultHttpClient();
try
{
//Define a HttpGet request; You can choose between HttpPost, HttpDelete or HttpPut also.
//Choice depends on type of method you will be invoking.
HttpGet getRequest = new HttpGet("http://localhost:9084/ehcache-server/rest/screeningInstance/2221");
//Set the API media type in http accept header
getRequest.addHeader("accept", "application/x-java-serialized-object");
//Send the request; It will immediately return the response in HttpResponse object
HttpResponse response = httpClient.execute(getRequest);
//verify the valid error code first
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != 200)
{
throw new RuntimeException("Failed with HTTP error code : " + statusCode);
}
//Now pull back the response object
HttpEntity httpEntity = response.getEntity();
byte[] resultByteArray = EntityUtils.toByteArray(httpEntity);
Person person = (Person)SerializationUtils.deserialize(resultByteArray);
}
finally
{
//Important: Close the connect
httpClient.getConnectionManager().shutdown();
}
}
}
class Person implements Serializable{
String name;
String id;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
#Override
public String toString() {
return "Person [name=" + name + ", id=" + id + "]";
}
}

Answer 1

I got the solution. It was mistake in my code:
While putting object, I have written below code. That was doing two time serialization. First from Person object to byte[] and second from byte[] to byte[].
SerializableEntity personSEntity = new SerializableEntity(SerializationUtils.serialize(person));
putRequest.setEntity(personSEntity);
This is the right approach:
SerializableEntity personSEntity = new SerializableEntity(person);
putRequest.setEntity(personSEntity);
After getting binary from REST, code should be like below to get Object:
HttpEntity httpEntity = response.getEntity();
InputStream inputStream = null;
try {
inputStream = httpEntity.getContent();
Person p = (Person) SerializationUtils.deserialize(inputStream);
System.out.println("Person:" + p.getName());
}
finally {
inputStream.close();
}
This worked like CHARM !!