Added CommonsHttpRequestExecutor (INT-614).

org.springframework.integration.http/src/main/java/org/springframework/integration/http/CommonsHttpRequestExecutor.java

@@ -0,0 +1,274 @@
+/*
+ * Copyright 2002-2009 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.integration.http;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.zip.GZIPInputStream;
+
+import org.apache.commons.httpclient.Header;
+import org.apache.commons.httpclient.HttpClient;
+import org.apache.commons.httpclient.HttpException;
+import org.apache.commons.httpclient.HttpMethod;
+import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager;
+import org.apache.commons.httpclient.methods.ByteArrayRequestEntity;
+import org.apache.commons.httpclient.methods.DeleteMethod;
+import org.apache.commons.httpclient.methods.EntityEnclosingMethod;
+import org.apache.commons.httpclient.methods.GetMethod;
+import org.apache.commons.httpclient.methods.HeadMethod;
+import org.apache.commons.httpclient.methods.OptionsMethod;
+import org.apache.commons.httpclient.methods.PostMethod;
+import org.apache.commons.httpclient.methods.PutMethod;
+import org.apache.commons.httpclient.methods.TraceMethod;
+
+import org.springframework.context.i18n.LocaleContext;
+import org.springframework.context.i18n.LocaleContextHolder;
+import org.springframework.integration.http.AbstractHttpRequestExecutor;
+import org.springframework.integration.http.HttpRequest;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Implementation of {@link HttpRequestExecutor} that uses a commons-http
+ * {@link HttpClient} to execute {@link HttpRequest} instances.
+ * 
+ * @author Mark Fisher
+ * @author Juergen Hoeller
+ * @since 1.0.2
+ */
+public class CommonsHttpRequestExecutor extends AbstractHttpRequestExecutor {
+
+	/**
+	 * Default timeout value if no HttpClient is explicitly provided.
+	 */
+	private static final int DEFAULT_READ_TIMEOUT_MILLISECONDS = (60 * 1000);
+
+	private HttpClient httpClient;
+
+
+	/**
+	 * Create a new CommonsHttpRequestExecutor with a default HttpClient that
+	 * uses a default MultiThreadedHttpConnectionManager.
+	 * Sets the socket read timeout to {@link #DEFAULT_READ_TIMEOUT_MILLISECONDS}.
+	 * @see org.apache.commons.httpclient.HttpClient
+	 * @see org.apache.commons.httpclient.MultiThreadedHttpConnectionManager
+	 */
+	public CommonsHttpRequestExecutor() {
+		this.httpClient = new HttpClient(new MultiThreadedHttpConnectionManager());
+		this.setReadTimeout(DEFAULT_READ_TIMEOUT_MILLISECONDS);
+	}
+
+	/**
+	 * Create a new CommonsHttpRequestExecutor with the given HttpClient
+	 * instance. The socket read timeout of the provided HttpClient will not be
+	 * changed.
+	 * @param httpClient the HttpClient instance to use for this request executor
+	 */
+	public CommonsHttpRequestExecutor(HttpClient httpClient) {
+		this.setHttpClient(httpClient);
+	}
+
+
+	/**
+	 * Set the HttpClient instance to use for this request executor.
+	 */
+	public void setHttpClient(HttpClient httpClient) {
+		Assert.notNull(httpClient, "httpClient must not be null");
+		this.httpClient = httpClient;
+	}
+
+	/**
+	 * Return the HttpClient instance that this request executor uses.
+	 */
+	public HttpClient getHttpClient() {
+		return this.httpClient;
+	}
+
+	/**
+	 * Set the socket read timeout for the underlying HttpClient. A value of 0
+	 * means <emphasis>never</emphasis> timeout. 
+	 * @param timeout the timeout value in milliseconds
+	 * @see org.apache.commons.httpclient.params.HttpConnectionManagerParams#setSoTimeout(int)
+	 * @see #DEFAULT_READ_TIMEOUT_MILLISECONDS
+	 */
+	public void setReadTimeout(int timeout) {
+		if (timeout < 0) {
+			throw new IllegalArgumentException("timeout must be a non-negative value");
+		}
+		this.httpClient.getHttpConnectionManager().getParams().setSoTimeout(timeout);
+	}
+
+	@Override
+	protected InputStream doExecuteRequest(HttpRequest request) throws Exception {
+		HttpMethod httpMethod = createHttpMethod(request);
+		try {
+			if (httpMethod instanceof EntityEnclosingMethod) {
+				setRequestBody((EntityEnclosingMethod) httpMethod, request.getBody(), request.getContentType());
+			}
+			executeHttpMethod(getHttpClient(), httpMethod);
+			validateResponse(httpMethod);
+			return readResponseBody(httpMethod);
+		}
+		finally {
+			// Need to explicitly release because it might be pooled.
+			httpMethod.releaseConnection();
+		}
+	}
+
+	/**
+	 * Create a HttpMethod for the given {@link HttpRequest}.
+	 * <p>This implementation creates an HttpMethod with the request's target
+	 * URL as well as the "Accept-Language" and "Accept-Encoding" headers. If
+	 * the method is "POST" or "PUT", the "Content-Type" header will also be
+	 * set as specified in the given request.
+	 * @param request the HTTP request to create a method for
+	 * @return the HttpMethod instance
+	 */
+	private HttpMethod createHttpMethod(HttpRequest request) {
+		String url = request.getTargetUrl().toString();
+		String methodName = request.getRequestMethod();
+		HttpMethod httpMethod = null;
+		if ("GET".equals(methodName)) {
+			httpMethod = new GetMethod(url);
+		}
+		else if ("POST".equals(methodName)) {
+			httpMethod = new PostMethod(url);
+		}
+		else if ("PUT".equals(methodName)) {
+			httpMethod = new PutMethod(url);
+		}
+		else if ("DELETE".equals(methodName)) {
+			httpMethod = new DeleteMethod(url);
+		}
+		else if ("TRACE".equals(methodName)) {
+			httpMethod = new TraceMethod(url);
+		}
+		else if ("HEAD".equals(methodName)) {
+			httpMethod = new HeadMethod(url);
+		}
+		else if ("OPTIONS".equals(methodName)) {
+			httpMethod = new OptionsMethod(url);
+		}
+		else {
+			throw new UnsupportedOperationException("unsupported request method '" + methodName + "'");
+		}
+		LocaleContext locale = LocaleContextHolder.getLocaleContext();
+		if (locale != null) {
+			httpMethod.addRequestHeader(HTTP_HEADER_ACCEPT_LANGUAGE, StringUtils.toLanguageTag(locale.getLocale()));
+		}
+		if (isAcceptGzipEncoding()) {
+			httpMethod.addRequestHeader(HTTP_HEADER_ACCEPT_ENCODING, ENCODING_GZIP);
+		}
+		if (httpMethod instanceof EntityEnclosingMethod) {
+			String contentType = request.getContentType();
+			if (contentType != null) {
+				httpMethod.addRequestHeader(HTTP_HEADER_CONTENT_TYPE, contentType);
+			}
+		}
+		return httpMethod;
+	}
+
+	/**
+	 * Set the given byte stream as the request body.
+	 * <p>The default implementation simply sets the byte stream as the
+	 * EntityEnclosingMethod's request body. This can be overridden, for
+	 * example, to write a specific encoding and potentially set appropriate
+	 * HTTP request headers.
+	 * @param httpMethod the EntityEnclosingMethod on which to set the request body
+	 * @param baos the ByteArrayOutputStream that contains the content
+	 * @param contentType the request body's content type
+	 * @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(
+			EntityEnclosingMethod httpMethod, ByteArrayOutputStream baos, String contentType)
+			throws IOException {
+		httpMethod.setRequestEntity(new ByteArrayRequestEntity(baos.toByteArray(), contentType));
+	}
+
+	/**
+	 * Execute the given HttpMethod instance.
+	 * @param httpClient the HttpClient responsible for execution
+	 * @param httpMethod the HttpMethod to be executed
+	 * @throws IOException if thrown by I/O methods
+	 * @see org.apache.commons.httpclient.HttpClient#executeMethod(org.apache.commons.httpclient.HttpMethod)
+	 */
+	private void executeHttpMethod(HttpClient httpClient, HttpMethod httpMethod) throws IOException {
+		httpClient.executeMethod(httpMethod);
+	}
+
+	/**
+	 * Validate the given response as contained in the HttpMethod object,
+	 * throwing an exception if it does not correspond to a successful HTTP response.
+	 * <p>This implementation rejects any HTTP status code beyond 2xx, to avoid
+	 * parsing the response body and trying to read from a corrupted stream.
+	 * @param httpMethod the executed HttpMethod to validate
+	 * @throws IOException if validation failed
+	 * @see org.apache.commons.httpclient.methods.PostMethod#getStatusCode()
+	 * @see org.apache.commons.httpclient.HttpException
+	 */
+	private void validateResponse(HttpMethod httpMethod) throws IOException {
+		if (httpMethod.getStatusCode() >= 300) {
+			throw new HttpException(
+					"Did not receive successful HTTP response: status code = " + httpMethod.getStatusCode() +
+					", status message = [" + httpMethod.getStatusText() + "]");
+		}
+	}
+
+	/**
+	 * Extract the response body from the given executed request.
+	 * <p>This implementation simply fetches the HttpMethod's response
+	 * body stream. If the response is recognized as a GZIP response, the
+	 * InputStream will be wrapped in a GZIPInputStream.
+	 * @param httpMethod the HttpMethod from which to read the response body
+	 * @return an InputStream for the response body, or <code>null</code> if no response stream is available
+	 * @throws IOException if thrown by I/O methods
+	 * @see #isGzipResponse
+	 * @see java.util.zip.GZIPInputStream
+	 * @see org.apache.commons.httpclient.HttpMethod#getResponseBodyAsStream()
+	 */
+	private InputStream readResponseBody(HttpMethod httpMethod) throws IOException {
+		byte[] responseBody = httpMethod.getResponseBody();
+		InputStream responseStream = null;
+		if (responseBody != null) {
+			responseStream = new ByteArrayInputStream(responseBody);
+			if (isGzipResponse(httpMethod)) {
+				responseStream = new GZIPInputStream(responseStream);
+			}
+		}
+		return responseStream;
+	}
+
+	/**
+	 * Determine whether the given response indicates a GZIP response.
+	 * <p>This implementation checks whether the HTTP "Content-Encoding"
+	 * header contains "gzip" (in any casing).
+	 * @param httpMethod the HttpMethod to check
+	 * @return whether the given response indicates a GZIP response
+	 * @see org.apache.commons.httpclient.HttpMethod#getResponseHeader(String)
+	 */
+	private boolean isGzipResponse(HttpMethod httpMethod) {
+		Header encodingHeader = httpMethod.getResponseHeader(HTTP_HEADER_CONTENT_ENCODING);
+		return (encodingHeader != null && encodingHeader.getValue() != null
+				&& encodingHeader.getValue().toLowerCase().indexOf(ENCODING_GZIP) != -1);
+	}
+
+}

org.springframework.integration.http/src/main/java/org/springframework/integration/http/SimpleHttpRequestExecutor.java

@@ -32,7 +32,7 @@ import org.springframework.util.StringUtils;
 /**
  * Implementation of {@link HttpRequestExecutor} that uses {@link HttpURLConnection}
  * directly. This version has limited functionality but no additional dependencies.
- * For more features, see {@link CommonsHttpRequestExecutor}. (TODO)
+ * For more features, see {@link CommonsHttpRequestExecutor}.
  * 
  * @author Juergen Hoeller
  * @author Iwein Fuld