JarCastingjson-client-commons
a library for creating JSON RPC clients in Java
Installation
Artifact is provided as a Maven dependency
<dependency>
<groupId>ca.uhn.ws</groupId>
<artifactId>json-client-commons</artifactId>
<version>2.1</version>
</dependency>
Usage
To make a JSON RPC client you will need to do the following things:
Extend ca.uhn.model.json.BaseRequestParams with a class containing the parameters for your request:
import ca.uhn.model.json.BaseRequestParams;
public class RequestParams extends BaseRequestParams {
public String id;
}
Create a class into which the result will be deserialized
import java.util.Date;
public class Person {
public String name;
public Integer height;
public Date age;
}
The client uses Google Gson library to serialize and deserialize classes.
Extend ca.uhn.json.client.JsonClient with your class
import java.util.Date;
import ca.uhn.json.client.JsonClient;
public class MyClient extends JsonClient {
//specify the type into which the response will be deserialized
private static final Type PERSON = new TypeToken<Person>(){}.getType();
//specify the name of the operation which will be called on the service
private static final String OPERATION = "getPerson";
public MyClient(String url) {
super(url);
}
public Person getPerson(String id) throws Exception {
RequestParams params = new RequestParams();
params.id = id;
return callService(OPERATION, params, PERSON);
}
public static void main(String[] args) throws Exception {
System.out.println(new MyClient("http://localhost:8080/test-service/json-service").getPerson("123"));
}
}
The client will generate the following JSON when callService executes:
POST /test-service/json-service HTTP/1.1
User-Agent: Jakarta Commons-HttpClient/3.1
Host: localhost:8080
Content-Length: 82
Content-Type: application/json; charset=UTF-8
{
"jsonrpc": "2.0",
"method": "getPerson",
"params": {
"id": "123"
}
}
The service should reply with a response which looks like the following:
HTTP/1.1 200 OK
X-Powered-By: Servlet/2.5
Server: Sun GlassFish Enterprise Server v2.1.1
Content-Type: application/json;charset=ISO-8859-1
Transfer-Encoding: chunked
Date: Wed, 10 Oct 2012 20:59:36 GMT
{
"jsonrpc": "2.0",
"result": {
"name": "John",
"height": 180,
"age": "Oct 10, 2012 04:59:36 PM"
}
}
note that dates are serialized using the following format: MMM dd, yyyy hh:mm:ss a