Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.tuscany.sca.binding.jsonrpc.provider; import java.io.IOException; import java.io.OutputStream; import java.lang.reflect.Constructor; import java.lang.reflect.Method; import java.lang.reflect.Type; import java.util.List; import java.util.UUID; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.HttpStatus; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.ContentProducer; import org.apache.http.entity.EntityTemplate; import org.apache.http.entity.StringEntity; import org.apache.http.util.EntityUtils; import org.apache.tuscany.sca.assembly.EndpointReference; import org.apache.tuscany.sca.binding.jsonrpc.JSONRPCBinding; import org.apache.tuscany.sca.binding.jsonrpc.protocol.JsonRpc10Request; import org.apache.tuscany.sca.binding.jsonrpc.protocol.JsonRpc20Request; import org.apache.tuscany.sca.binding.jsonrpc.protocol.JsonRpcRequest; import org.apache.tuscany.sca.databinding.json.JSONDataBinding; import org.apache.tuscany.sca.databinding.json.jackson.JacksonHelper; import org.apache.tuscany.sca.interfacedef.DataType; import org.apache.tuscany.sca.interfacedef.Operation; import org.apache.tuscany.sca.interfacedef.java.JavaOperation; import org.apache.tuscany.sca.invocation.DataExchangeSemantics; import org.apache.tuscany.sca.invocation.Invoker; import org.apache.tuscany.sca.invocation.Message; import org.codehaus.jackson.JsonNode; import org.codehaus.jackson.map.ObjectMapper; import org.codehaus.jackson.map.type.TypeFactory; import org.codehaus.jackson.node.NullNode; import org.codehaus.jackson.node.ObjectNode; import org.oasisopen.sca.ServiceRuntimeException; /** * Invoker for the JSONRPC Binding * * @version $Rev: 1304128 $ $Date: 2012-03-22 23:19:17 +0000 (Thu, 22 Mar 2012) $ */ public class JsonRpcInvoker implements Invoker, DataExchangeSemantics { private EndpointReference endpointReference; private Operation operation; private String uri; private HttpClient httpClient; public JsonRpcInvoker(EndpointReference endpointReference, Operation operation, HttpClient httpClient) { this.endpointReference = endpointReference; this.operation = operation; this.uri = endpointReference.getDeployedURI(); this.httpClient = httpClient; } public Message invoke(Message msg) { HttpPost post = null; HttpResponse response = null; try { String requestId = UUID.randomUUID().toString(); post = new HttpPost(uri); HttpEntity entity = null; Object[] args = msg.getBody(); final String db = msg.getOperation().getInputWrapper().getDataBinding(); if (!db.equals(JSONDataBinding.NAME)) { Object[] params = new Object[0]; // Extract the arguments args = msg.getBody(); if (args instanceof Object[]) { params = (Object[]) args; } JsonRpcRequest req = null; if (JSONRPCBinding.VERSION_20 .equals(((JSONRPCBinding) endpointReference.getBinding()).getVersion())) { req = new JsonRpc20Request(requestId, msg.getOperation().getName(), params); } else { req = new JsonRpc10Request(requestId, msg.getOperation().getName(), params); } final JsonRpcRequest json = req; // Create content producer so that we can stream the json result out ContentProducer cp = new ContentProducer() { public void writeTo(OutputStream outstream) throws IOException { // mapper.writeValue(outstream, req.toJSONObject().toString()); try { json.write(outstream); } catch (Exception e) { throw new IOException(e); } } }; entity = new EntityTemplate(cp); } else { // Single string argument entity = new StringEntity((String) args[0], "UTF-8"); } post.setEntity(entity); response = httpClient.execute(post); if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) { //success entity = response.getEntity(); String entityResponse = EntityUtils.toString(entity); entity.consumeContent(); if (!db.equals(JSONDataBinding.NAME)) { ObjectNode jsonResponse = (ObjectNode) JacksonHelper.MAPPER.readTree(entityResponse); if (jsonResponse.has("error") && jsonResponse.get("error") != NullNode.instance) { processException(jsonResponse); } DataType<List<DataType>> outputType = operation.getOutputType(); DataType returnType = (outputType != null && !outputType.getLogical().isEmpty()) ? outputType.getLogical().get(0) : null; if (returnType == null) { msg.setBody(null); return msg; } //check requestId if (!requestId.equalsIgnoreCase(jsonResponse.get("id").getTextValue())) { throw new ServiceRuntimeException("Invalid response id:" + requestId); } JsonNode rawResult = jsonResponse.get("result"); Class<?> returnClass = returnType.getPhysical(); Type genericReturnType = returnType.getGenericType(); ObjectMapper mapper = createObjectMapper(returnClass); String json = mapper.writeValueAsString(rawResult); Object body = mapper.readValue(json, TypeFactory.type(genericReturnType)); msg.setBody(body); } else { msg.setBody(entityResponse); } } else { // Consume the content so the connection can be released response.getEntity().consumeContent(); throw new ServiceRuntimeException("Abnormal HTTP response: " + response.getStatusLine().toString()); } } catch (RuntimeException e) { throw e; } catch (Error e) { throw e; } catch (Exception e) { // e.printStackTrace(); msg.setFaultBody(e); } catch (Throwable e) { throw new ServiceRuntimeException(e); } return msg; } public static ObjectMapper createObjectMapper(Class<?> cls) { return JacksonHelper.createObjectMapper(cls); } private String opt(ObjectNode node, String name) { JsonNode value = node.get(name); if (value == null) { return null; } else { return value.getValueAsText(); } } /** * Generate and throw exception based on the data in the 'responseMessage' */ protected void processException(ObjectNode responseMessage) throws Throwable { // FIXME: We need to find a way to build Java exceptions out of the json-rpc error JsonNode error = responseMessage.get("error"); if (error != null) { Object data = error.get("data"); if (data instanceof ObjectNode) { ObjectNode fault = (ObjectNode) data; String javaClass = opt(fault, "class"); String message = opt(fault, "message"); String stackTrace = opt(fault, "stackTrace"); if (javaClass != null) { if (stackTrace != null) { message = message + "\n" + stackTrace; } ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); if (operation instanceof JavaOperation) { Method method = ((JavaOperation) operation).getJavaMethod(); classLoader = method.getDeclaringClass().getClassLoader(); } Class<? extends Throwable> exceptionClass = (Class<? extends Throwable>) Class .forName(javaClass, false, classLoader); Constructor<? extends Throwable> ctor = null; Throwable ex = null; try { ctor = exceptionClass.getConstructor(String.class, Throwable.class); ex = ctor.newInstance(message, null); } catch (NoSuchMethodException e1) { try { ctor = exceptionClass.getConstructor(String.class); ex = ctor.newInstance(message); } catch (NoSuchMethodException e2) { try { ctor = exceptionClass.getConstructor(Throwable.class); ex = ctor.newInstance(null); } catch (NoSuchMethodException e3) { ctor = exceptionClass.getConstructor(); ex = ctor.newInstance(); } } } throw ex; } } throw new ServiceRuntimeException(error.toString()); } } @Override public boolean allowsPassByReference() { return true; } }