HTTPProtocol.java

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 *
 * Pentaho Data Integration
 *
 * Copyright (C) 2002-2016 by Pentaho : http://www.pentaho.com
 *
 *******************************************************************************
 *
 * 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,
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package org.pentaho.di.core;

import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;

import org.apache.commons.httpclient.Credentials;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.UsernamePasswordCredentials;
import org.apache.commons.httpclient.auth.AuthScope;
import org.apache.commons.httpclient.auth.AuthenticationException;
import org.apache.commons.httpclient.methods.GetMethod;
import org.pentaho.di.cluster.SlaveConnectionManager;
import org.pentaho.di.core.util.Utils;

/**
 * HTTP
 *
 * This class contains HTTP protocol properties such as request headers. Response headers and other properties of the
 * HTTP protocol can be added to this class.
 *
 * @author sflatley
 *
 */
public class HTTPProtocol {

  /*
   * Array of HTTP request headers- this list is incomplete and more headers can be added as needed.
   */

  private static final String[] requestHeaders = { "accept", "accept-charset", "cache-control", "content-type" };

  /**
   * @return array of HTTP request headers
   */
  public static String[] getRequestHeaders() {
    return requestHeaders;
  }

  /**
   * Performs a get on urlAsString using username and password as credentials.
   *
   * If the status code returned not -1 and 401 then the contents are returned. If the status code is 401 an
   * AuthenticationException is thrown.
   *
   * All other values of status code are not dealt with but logic can be added as needed.
   *
   * @param urlAsString
   * @param username
   * @param password
   * @param encoding
   * @return
   * @throws MalformedURLException
   * @throws IOException
   */
  public String get( String urlAsString, String username, String password ) throws MalformedURLException,
    IOException, AuthenticationException {

    HttpClient httpClient = SlaveConnectionManager.getInstance().createHttpClient();
    GetMethod getMethod = new GetMethod( urlAsString );
    if ( !Utils.isEmpty( username ) ) {
      httpClient.getParams().setAuthenticationPreemptive( true );
      Credentials defaultcreds = new UsernamePasswordCredentials( username, password );
      httpClient.getState().setCredentials( AuthScope.ANY, defaultcreds );
    }
    int statusCode = httpClient.executeMethod( getMethod );
    StringBuilder bodyBuffer = new StringBuilder();

    if ( statusCode != -1 ) {
      if ( statusCode != 401 ) {

        // the response
        InputStreamReader inputStreamReader = new InputStreamReader( getMethod.getResponseBodyAsStream() );

        int c;
        while ( ( c = inputStreamReader.read() ) != -1 ) {
          bodyBuffer.append( (char) c );
        }
        inputStreamReader.close();

      } else {
        throw new AuthenticationException();
      }
    }

    // Display response
    return bodyBuffer.toString();
  }
}