/*
* Copyright (C) 2011 Develnix.com
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.json.rpc.client;
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import org.json.rpc.commons.GsonTypeChecker;
import org.json.rpc.commons.JsonRpcClientException;
import org.json.rpc.commons.JsonRpcRemoteException;
import org.json.rpc.commons.TypeChecker;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.StringReader;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Random;
public final class JsonRpcInvoker {
private static final Logger LOG = LoggerFactory.getLogger(JsonRpcInvoker.class);
private final Random rand = new Random();
private final TypeChecker typeChecker;
public JsonRpcInvoker() {
this(new GsonTypeChecker());
}
public JsonRpcInvoker(TypeChecker typeChecker) {
this.typeChecker = typeChecker;
}
public <T> T get(final JsonRpcClientTransport transport, final String handle, final Class<T>... classes) {
for (Class<T> clazz : classes) {
typeChecker.isValidInterface(clazz);
}
return (T) Proxy.newProxyInstance(JsonRpcInvoker.class.getClassLoader(), classes, new InvocationHandler() {
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
return JsonRpcInvoker.this.invoke(handle, transport, method, args);
}
});
}
private Object invoke(String handleName,
JsonRpcClientTransport transport, Method method,
Object[] args) throws Throwable {
int id = rand.nextInt(Integer.MAX_VALUE);
String methodName = handleName + "." + method.getName();
Gson gson = new Gson();
JsonObject req = new JsonObject();
req.addProperty("id", id);
req.addProperty("method", methodName);
JsonArray params = new JsonArray();
if (args != null) {
for (Object o : args) {
params.add(gson.toJsonTree(o));
}
}
req.add("params", params);
String requestData = req.toString();
LOG.debug("JSON-RPC >> {}", requestData);
String responseData;
try {
responseData = transport.call(requestData);
} catch (Exception e) {
throw new JsonRpcClientException("unable to get data from transport", e);
}
LOG.debug("JSON-RPC << {}", responseData);
JsonParser parser = new JsonParser();
JsonObject resp = (JsonObject) parser.parse(new StringReader(responseData));
JsonElement result = resp.get("result");
JsonElement error = resp.get("error");
if (error != null && !error.isJsonNull()) {
if (error.isJsonPrimitive()) {
throw new JsonRpcRemoteException(error.getAsString());
} else if (error.isJsonObject()) {
JsonObject o = error.getAsJsonObject();
Integer code = (o.has("code") ? o.get("code").getAsInt() : null);
String message = (o.has("message") ? o.get("message").getAsString() : null);
String data = (o.has("data") ? o.get("data").getAsString() : null);
throw new JsonRpcRemoteException(code, message, data);
} else {
throw new JsonRpcRemoteException("unknown error, data = " + error.toString());
}
}
if (method.getReturnType() == void.class) {
return null;
}
return gson.fromJson(result.toString(), method.getReturnType());
}
}