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.io.UnsupportedEncodingException; import java.net.URLDecoder; import java.util.List; import javax.security.auth.login.LoginException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.codec.binary.Base64; import org.apache.tuscany.sca.assembly.Binding; 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.JsonRpc10Response; import org.apache.tuscany.sca.binding.jsonrpc.protocol.JsonRpc20BatchRequest; import org.apache.tuscany.sca.binding.jsonrpc.protocol.JsonRpc20Error; import org.apache.tuscany.sca.binding.jsonrpc.protocol.JsonRpc20Request; import org.apache.tuscany.sca.binding.jsonrpc.protocol.JsonRpc20Response; import org.apache.tuscany.sca.binding.jsonrpc.protocol.JsonRpcResponse; import org.apache.tuscany.sca.databinding.json.JSONDataBinding; import org.apache.tuscany.sca.databinding.json.jackson.JacksonHelper; import org.apache.tuscany.sca.interfacedef.Operation; import org.apache.tuscany.sca.invocation.Message; import org.apache.tuscany.sca.invocation.MessageFactory; import org.apache.tuscany.sca.runtime.RuntimeEndpoint; import org.codehaus.jackson.JsonNode; import org.codehaus.jackson.node.ArrayNode; import org.codehaus.jackson.node.JsonNodeFactory; import org.codehaus.jackson.node.ObjectNode; import org.oasisopen.sca.ServiceRuntimeException; public class JsonRpcServlet extends HttpServlet { private static final long serialVersionUID = 1L; transient MessageFactory messageFactory; transient Binding binding; transient String serviceName; transient Object serviceInstance; transient RuntimeEndpoint endpoint; transient Class<?> serviceInterface; public JsonRpcServlet(MessageFactory messageFactory, RuntimeEndpoint endpoint, Class<?> serviceInterface, Object serviceInstance) { this.endpoint = endpoint; this.messageFactory = messageFactory; this.binding = endpoint.getBinding(); this.serviceName = binding.getName(); this.serviceInterface = serviceInterface; this.serviceInstance = serviceInstance; } @Override protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { if ("smd".equals(request.getQueryString())) { handleSMDRequest(request, response); return; } try { handleJsonRpcInvocation(request, response); } catch (RuntimeException re) { if (re.getCause() instanceof javax.security.auth.login.LoginException) { response.setHeader("WWW-Authenticate", "BASIC realm=\"" + "ldap-realm" + "\""); response.sendError(HttpServletResponse.SC_UNAUTHORIZED); } else { throw re; } } } private void handleJsonRpcInvocation(HttpServletRequest request, HttpServletResponse response) throws UnsupportedEncodingException, IOException, ServletException { // Decode using the charset in the request if it exists otherwise // use UTF-8 as this is what all browser implementations use. // The JSON-RPC-Java JavaScript client is ASCII clean so it // although here we can correctly handle data from other clients // that do not escape non ASCII data String charset = request.getCharacterEncoding(); if (charset == null) { charset = "UTF-8"; } JsonNode root = null; if (request.getMethod().equals("GET")) { // if using GET Support (see http://groups.google.com/group/json-rpc/web/json-rpc-over-http) //parse the GET QueryString try { String params = new String( Base64.decodeBase64(URLDecoder.decode(request.getParameter("params"), charset).getBytes())); StringBuilder sb = new StringBuilder(); sb.append("{"); sb.append("\"method\": \"" + request.getParameter("method") + "\","); sb.append("\"params\": " + params + ","); sb.append("\"id\":" + request.getParameter("id")); sb.append("}"); root = JacksonHelper.MAPPER.readTree(sb.toString()); } catch (Throwable e) { JsonRpc10Response error = new JsonRpc10Response( JsonNodeFactory.instance.textNode(request.getParameter("id")), e); error.write(response.getWriter()); return; } } else { root = JacksonHelper.MAPPER.readTree(request.getReader()); } try { if (root.isArray()) { ArrayNode input = (ArrayNode) root; JsonRpc20BatchRequest batchReq = new JsonRpc20BatchRequest(input); for (int i = 0; i < batchReq.getRequests().size(); i++) { JsonRpcResponse result = batchReq.getBatchResponse().getResponses().get(i); if (result == null) { result = invoke(batchReq.getRequests().get(i)); batchReq.getBatchResponse().getResponses().set(i, result); } } ArrayNode responses = batchReq.getBatchResponse().toJSONArray(); JacksonHelper.MAPPER.writeValue(response.getWriter(), responses); } else { if (root.has("jsonrpc")) { JsonRpc20Request jsonReq = new JsonRpc20Request((ObjectNode) root); JsonRpcResponse jsonResult = invoke(jsonReq); if (jsonResult != null) { jsonResult.write(response.getWriter()); } } else { JsonRpc10Request jsonReq = new JsonRpc10Request((ObjectNode) root); JsonRpc10Response jsonResult = invoke(jsonReq); if (jsonResult != null) { jsonResult.write(response.getWriter()); } } } } catch (Throwable e) { throw new ServletException(e); } } private JsonRpcResponse invoke(JsonRpc20Request request) throws Exception { if (request.isNotification()) { return null; } // invoke the request String method = request.getMethod(); Object[] params = request.getParams(); Object result = null; Operation jsonOperation = findOperation(method); // Invoke the get operation on the service implementation Message requestMessage = messageFactory.createMessage(); requestMessage.setOperation(jsonOperation); requestMessage.getHeaders().put("RequestMessage", request); if (jsonOperation.getInputWrapper().getDataBinding().equals(JSONDataBinding.NAME)) { requestMessage.setBody(new Object[] { JacksonHelper.toString(request.getJsonNode()) }); } else { requestMessage.setBody(params); } requestMessage.setBody(params); Message responseMessage = null; try { //result = wire.invoke(jsonOperation, args); responseMessage = endpoint.getInvocationChain(jsonOperation).getHeadInvoker().invoke(requestMessage); } catch (RuntimeException re) { if (re.getCause() instanceof javax.security.auth.login.LoginException) { throw re; } else { JsonRpc20Error error = new JsonRpc20Error(request.getId(), re); return error; } } if (!responseMessage.isFault()) { if (jsonOperation.getOutputWrapper().getDataBinding().equals(JSONDataBinding.NAME)) { result = responseMessage.getBody(); return new JsonRpc20Response((ObjectNode) JacksonHelper.MAPPER.readTree(result.toString())); } else { if (jsonOperation.getOutputType().getLogical().size() == 0) { // void operation (json-rpc notification) try { JsonRpc20Response response = new JsonRpc20Response(request.getId(), null); return response; } catch (Exception e) { throw new ServiceRuntimeException("Unable to create JSON response", e); } } else { // regular operation returning some value try { result = responseMessage.getBody(); JsonRpc20Response response = new JsonRpc20Response(request.getId(), (JsonNode) result); //get response to send to client return response; } catch (Exception e) { throw new ServiceRuntimeException("Unable to create JSON response", e); } } } } else { //exception thrown while executing the invocation Throwable exception = (Throwable) responseMessage.getBody(); JsonRpc20Error error = new JsonRpc20Error(request.getId(), exception); return error; } } private JsonRpc10Response invoke(JsonRpc10Request request) throws Exception { if (request.isNotification()) { return null; } // invoke the request String method = request.getMethod(); Object[] params = request.getParams(); Object result = null; Operation jsonOperation = findOperation(method); // Invoke the get operation on the service implementation Message requestMessage = messageFactory.createMessage(); requestMessage.setOperation(jsonOperation); requestMessage.getHeaders().put("RequestMessage", request); if (jsonOperation.getInputWrapper().getDataBinding().equals(JSONDataBinding.NAME)) { requestMessage.setBody(new Object[] { JacksonHelper.toString(request.getJsonNode()) }); } else { requestMessage.setBody(params); } Message responseMessage = null; try { //result = wire.invoke(jsonOperation, args); responseMessage = endpoint.getInvocationChain(jsonOperation).getHeadInvoker().invoke(requestMessage); } catch (RuntimeException e) { if (e.getCause() instanceof LoginException) { throw e; } else { JsonRpc10Response error = new JsonRpc10Response(request.getId(), e); return error; } } if (!responseMessage.isFault()) { if (jsonOperation.getOutputWrapper().getDataBinding().equals(JSONDataBinding.NAME)) { result = responseMessage.getBody(); return new JsonRpc10Response((ObjectNode) JacksonHelper.MAPPER.readTree(result.toString())); } else { if (jsonOperation.getOutputType().getLogical().size() == 0) { // void operation (json-rpc notification) JsonRpc10Response response = new JsonRpc10Response(request.getId(), JsonNodeFactory.instance.nullNode()); return response; } else { // regular operation returning some value result = responseMessage.getBody(); JsonRpc10Response response = new JsonRpc10Response(request.getId(), (JsonNode) result); //get response to send to client return response; } } } else { //exception thrown while executing the invocation Throwable exception = (Throwable) responseMessage.getBody(); JsonRpc10Response error = new JsonRpc10Response(request.getId(), exception); return error; } } /** * Find the operation from the component service contract * @param componentService * @param method * @return */ private Operation findOperation(String method) { if (method.contains(".")) { method = method.substring(method.lastIndexOf(".") + 1); } List<Operation> operations = endpoint.getComponentServiceInterfaceContract().getInterface().getOperations(); //endpoint.getComponentTypeServiceInterfaceContract().getInterface().getOperations(); //componentService.getBindingProvider(binding).getBindingInterfaceContract().getInterface().getOperations(); Operation result = null; for (Operation o : operations) { if (o.isDynamic()) return o; if (o.getName().equalsIgnoreCase(method)) { result = o; break; } } return result; } /** * handles requests for the SMD descriptor for a service */ protected void handleSMDRequest(HttpServletRequest request, HttpServletResponse response) throws IOException, UnsupportedEncodingException { String serviceUrl = request.getRequestURL().toString(); String smd = null; if (JSONRPCBinding.VERSION_20.equals(((JSONRPCBinding) binding).getVersion())) { smd = JavaToSmd.interfaceToSmd20(serviceInterface, serviceUrl); } else { smd = JavaToSmd.interfaceToSmd(serviceInterface, serviceUrl); } response.setContentType("application/json;charset=utf-8"); OutputStream out = response.getOutputStream(); byte[] bout = smd.getBytes("UTF-8"); out.write(bout); out.flush(); out.close(); } }