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/* * Copyright 2002-2005 the original author or authors. * * 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.springframework.remoting.httpinvoker; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpException; import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager; import org.apache.commons.httpclient.methods.PostMethod; import org.springframework.remoting.support.RemoteInvocationResult; /** * HttpInvokerRequestExecutor implementation that uses * <a href="http://jakarta.apache.org/commons/httpclient">Jakarta Commons HttpClient</a> * to execute POST requests. Compatible with Commons HttpClient 2.0 and 3.0. * * <p>Allows to use a preconfigured HttpClient instance, potentially * with authentication, HTTP connection pooling, etc. Also designed * for easy subclassing, customizing specific template methods. * * @author Juergen Hoeller * @since 1.1 * @see SimpleHttpInvokerRequestExecutor */ public class CommonsHttpInvokerRequestExecutor extends AbstractHttpInvokerRequestExecutor { private HttpClient httpClient; /** * Create a new CommonsHttpInvokerRequestExecutor with a default * HttpClient that uses a default MultiThreadedHttpConnectionManager. * @see org.apache.commons.httpclient.HttpClient * @see org.apache.commons.httpclient.MultiThreadedHttpConnectionManager */ public CommonsHttpInvokerRequestExecutor() { this.httpClient = new HttpClient(new MultiThreadedHttpConnectionManager()); } /** * Create a new CommonsHttpInvokerRequestExecutor with the given * HttpClient instance. * @param httpClient the HttpClient instance to use for this request executor */ public CommonsHttpInvokerRequestExecutor(HttpClient httpClient) { this.httpClient = httpClient; } /** * Set the HttpClient instance to use for this request executor. */ public void setHttpClient(HttpClient httpClient) { this.httpClient = httpClient; } /** * Return the HttpClient instance that this request executor uses. */ public HttpClient getHttpClient() { return httpClient; } /** * Execute the given request through Commons HttpClient. * <p>This method implements the basic processing workflow: * The actual work happens in this class's template methods. * @see #createPostMethod * @see #setRequestBody * @see #executePostMethod * @see #validateResponse * @see #getResponseBody */ protected RemoteInvocationResult doExecuteRequest(HttpInvokerClientConfiguration config, ByteArrayOutputStream baos) throws IOException, ClassNotFoundException { PostMethod postMethod = createPostMethod(config); try { setRequestBody(config, postMethod, baos); executePostMethod(config, getHttpClient(), postMethod); validateResponse(config, postMethod); InputStream responseBody = getResponseBody(config, postMethod); return readRemoteInvocationResult(responseBody, config.getCodebaseUrl()); } finally { // Need to explicitly release because it might be pooled. postMethod.releaseConnection(); } } /** * Create a PostMethod for the given configuration. * <p>The default implementation creates a standard PostMethod with * "application/x-java-serialized-object" as "Content-Type" header. * @param config the HTTP invoker configuration that specifies the * target service * @return the PostMethod instance * @throws IOException if thrown by I/O methods */ protected PostMethod createPostMethod(HttpInvokerClientConfiguration config) throws IOException { PostMethod postMethod = new PostMethod(config.getServiceUrl()); postMethod.setRequestHeader(HTTP_HEADER_CONTENT_TYPE, CONTENT_TYPE_SERIALIZED_OBJECT); return postMethod; } /** * Set the given serialized remote invocation as request body. * <p>The default implementation simply sets the serialized invocation * as the PostMethod's request body. This can be overridden, for example, * to write a specific encoding and potentially set appropriate HTTP * request headers. * @param config the HTTP invoker configuration that specifies the target service * @param postMethod the PostMethod to set the request body on * @param baos the ByteArrayOutputStream that contains the serialized * RemoteInvocation object * @throws IOException if thrown by I/O methods * @see org.apache.commons.httpclient.methods.PostMethod#setRequestBody(java.io.InputStream) * @see org.apache.commons.httpclient.methods.PostMethod#setRequestEntity * @see org.apache.commons.httpclient.methods.InputStreamRequestEntity */ protected void setRequestBody(HttpInvokerClientConfiguration config, PostMethod postMethod, ByteArrayOutputStream baos) throws IOException { // Need to call setRequestBody for compatibility with Commons HttpClient 2.0 postMethod.setRequestBody(new ByteArrayInputStream(baos.toByteArray())); } /** * Execute the given PostMethod instance. * @param config the HTTP invoker configuration that specifies the target service * @param httpClient the HttpClient to execute on * @param postMethod the PostMethod to execute * @throws IOException if thrown by I/O methods * @see org.apache.commons.httpclient.HttpClient#executeMethod(org.apache.commons.httpclient.HttpMethod) */ protected void executePostMethod(HttpInvokerClientConfiguration config, HttpClient httpClient, PostMethod postMethod) throws IOException { httpClient.executeMethod(postMethod); } /** * Validate the given response as contained in the PostMethod object, * throwing an exception if it does not correspond to a successful HTTP response. * <p>Default implementation rejects any HTTP status code beyond 2xx, to avoid * parsing the response body and trying to deserialize from a corrupted stream. * @param config the HTTP invoker configuration that specifies the target service * @param postMethod the executed PostMethod to validate * @throws IOException if validation failed * @see org.apache.commons.httpclient.methods.PostMethod#getStatusCode() * @see org.apache.commons.httpclient.HttpException */ protected void validateResponse(HttpInvokerClientConfiguration config, PostMethod postMethod) throws IOException { if (postMethod.getStatusCode() >= 300) { throw new HttpException("Did not receive successful HTTP response: status code = " + postMethod.getStatusCode() + ", status message = [" + postMethod.getStatusText() + "]"); } } /** * Extract the response body from the given executed remote invocation * request. * <p>The default implementation simply fetches the PostMethod's response * body stream. This can be overridden, for example, to check for GZIP * response encoding and wrap the returned InputStream in a GZIPInputStream. * @param config the HTTP invoker configuration that specifies the target service * @param postMethod the PostMethod to read the response body from * @return an InputStream for the response body * @throws IOException if thrown by I/O methods * @see org.apache.commons.httpclient.methods.PostMethod#getResponseBodyAsStream() * @see org.apache.commons.httpclient.methods.PostMethod#getResponseHeader(String) */ protected InputStream getResponseBody(HttpInvokerClientConfiguration config, PostMethod postMethod) throws IOException { return postMethod.getResponseBodyAsStream(); } }