bpel-rest-extensions/src/main/java/org/apache/ode/bpel/extension/bpel4restlight/http/LowLevelRestApi.java

/*
 * 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.ode.bpel.extension.bpel4restlight.http;

import java.io.IOException;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.ode.bpel.common.FaultException;
import org.apache.ode.bpel.extension.bpel4restlight.Bpel4RestLightExtensionBundle;

/**
 * This class eases HTTP method execution by providing fault handling and
 * automated response information processing
 * 
 * @author Michael Hahn (mhahn.dev@gmail.com)
 */
public class LowLevelRestApi {

	// HttpClient used for communication
	private static HttpClient httpClient = new HttpClient();

	/**
	 * Executes a passed HttpMethod (method type is either PUT, POST, GET or DELETE)
	 * and returns a HttpResponseMessage
	 * 
	 * @param method
	 *            Method to execute
	 * @return HttpResponseMessage which contains all information about the
	 *         execution
	 */
	public static HttpResponseMessage executeHttpMethod(HttpMethod method) throws FaultException {

		HttpResponseMessage responseMessage = null;

		try {
			// Execute Request
			LowLevelRestApi.httpClient.executeMethod(method);
			
			responseMessage = LowLevelRestApi.extractResponseInformation(method);
		} catch (HttpException e) {
			throw new FaultException(Bpel4RestLightExtensionBundle.FAULT_QNAME,
					"BPEL4REST: Execution of HTTP method '" + method.getName() + "' caused an exception: " + e.getMessage(), e);
		} catch (IOException e) {
			throw new FaultException(Bpel4RestLightExtensionBundle.FAULT_QNAME,
					"BPEL4REST: Execution of HTTP method '" + method.getName() + "' caused an exception: " + e.getMessage(), e);
		} finally {
			// Release connection
			method.releaseConnection();
		}

		// Extract response information and return
		return responseMessage;
	}

	/**
	 * Extracts the response information from an executed HttpMethod
	 * 
	 * @param method
	 *            The HTTP method
	 * @return The extracted response information
	 * @throws IOException
	 */
	private static HttpResponseMessage extractResponseInformation(HttpMethod method) throws IOException {
		// Create and return HttpResponseMethod
		HttpResponseMessage responseMessage = new HttpResponseMessage();
		
		responseMessage.setStatusCode(method.getStatusCode());
		responseMessage.setResponseBody(method.getResponseBodyAsString());

		return responseMessage;
	}

}