ClientUtil.java

/*
 * This program is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software 
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this 
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html 
 * or from the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * Copyright 2010 Pentaho Corporation.  All rights reserved. 
 * 
 * @created Jan, 2010 
 * @author James Dixon
 * 
 */
package org.pentaho.platform.util.client;

import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.httpclient.Credentials;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.UsernamePasswordCredentials;
import org.apache.commons.httpclient.auth.AuthScope;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;

public class ClientUtil {

  /**
   * Returns an instance of an HttpClient. Only one is created per 
   * ConnectionServiceClient so all calls should be made synchronously.
   * @return The HTTP client to be used for web service calls
   */
  public static HttpClient getClient( String userId, String password) {
    
    HttpClient httpClientInstance = new HttpClient();
    if ((userId != null) && (userId.length() > 0) && (password != null)
        && (password.length() > 0)) {
        Credentials creds = new UsernamePasswordCredentials(userId, password);
        httpClientInstance.getState().setCredentials(AuthScope.ANY, creds);
        httpClientInstance.getParams().setAuthenticationPreemptive(true);
      }
    return httpClientInstance;
  }
  
  /**
   * Submits an HTTP result with the provided HTTPMethod and returns a dom4j document of the
   * response
   * @param callMethod
   * @return
   * @throws ConnectionServiceException
   */
  public static org.dom4j.Document getResultDom4jDocument( HttpClient client, HttpMethod callMethod ) throws ServiceException {
    
    try {
      // execute the HTTP call
      int status = client.executeMethod(callMethod);
      if( status != HttpStatus.SC_OK) {
        throw new ServiceException("Web service call failed with code "+status); //$NON-NLS-1$
      }
      // get the result as a string
      InputStream in = callMethod.getResponseBodyAsStream();
      byte buffer[] = new byte[2048];
      int n = in.read(buffer);
      StringBuilder sb = new StringBuilder();
      while( n != -1 ) {
        sb.append( new String( buffer, 0, n ) );
        n = in.read(buffer);
      }
      String result = sb.toString();
      // convert to XML
      return DocumentHelper.parseText( result );
    } catch (IOException e) {
      throw new ServiceException(e);
    } catch (DocumentException e) {
      throw new ServiceException(e);
    }

  }
}