uimaj-2.2.0-incubating/uimaj-core/src/main/java/org/apache/uima/internal/util/BrowserUtil.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.uima.internal.util;

import java.io.IOException;

/**
 * The <code>BrowserUtil</code> class provides one static method -
 * <code>openUrlInDefaultBrowser</code>, which opens the given URL in the default web browser for
 * the current user of the system. Current implementation supports Windows, Linux and some Unix
 * systems.
 * 
 * 
 */

public class BrowserUtil {

  /** The internal ID of the OS we are running on */
  private static int __osId;

  /** The command that launches system browser */
  private static String __browserLauncher;

  /** JVM constant for any Windows NT JVM */
  private static final int WINDOWS_NT = 0;

  /** JVM constant for any Windows 9x JVM */
  private static final int WINDOWS_9x = 1;

  /** JVM constant for Linux JVM */
  private static final int LINUX = 2;

  /** JVM constant for any other platform */
  private static final int OTHER = -1;

  /**
   * The first parameter that needs to be passed into Runtime.exec() to open the default web browser
   * on Windows.
   */
  private static final String FIRST_WINDOWS_PARAMETER = "/c";

  /** The second parameter for Runtime.exec() on Windows. */
  private static final String SECOND_WINDOWS_PARAMETER = "start";

  /**
   * The third parameter for Runtime.exec() on Windows. This is a "title" parameter that the command
   * line expects. Setting this parameter allows URLs containing spaces to work.
   */
  private static final String THIRD_WINDOWS_PARAMETER = "\"\"";

  /**
   * The shell parameters for Mozilla, which assumes that the 'default' Mozilla profile exists.
   */
  private static final String MOZILLA_REMOTE_PARAMETER = "-remote";

  private static final String MOZILLA_OPEN_PARAMETER_START = "openURL(";

  private static final String MOZILLA_OPEN_PARAMETER_END = ")";

  /**
   * The shell parameters for Netscape that opens a given URL in an already-open copy of Netscape on
   * many command-line systems.
   */
  private static final String NETSCAPE_REMOTE_PARAMETER = "-remote";

  private static final String NETSCAPE_OPEN_PARAMETER_START = "'openURL(";

  private static final String NETSCAPE_OPEN_PARAMETER_END = ")'";

  /**
   * An initialization block that determines the operating system and the browser launcher command.
   */
  static {
    String osName = System.getProperty("os.name");
    if (osName.startsWith("Windows")) {
      if (osName.indexOf("9") > -1) {
        __osId = WINDOWS_9x;
        __browserLauncher = "command.com";
      } else {
        __osId = WINDOWS_NT;
        __browserLauncher = "cmd.exe";
      }
    } else if (osName.startsWith("Linux")) {
      __osId = LINUX;
      __browserLauncher = "mozilla";
    } else {
      __osId = OTHER;
      __browserLauncher = "netscape";
    }
  }

  /**
   * For testing only.
   * 
   * @param args
   *          [url_to_open]
   */
  public static void main(String args[]) {
    String url = (args.length > 0) ? args[0] : "http://apache.org";
    try {
      Process process = BrowserUtil.openUrlInDefaultBrowser(url);
      process.waitFor();
    } catch (Exception e) {
      System.err.println("Error in BrowserUtil.main():");
      e.printStackTrace(System.err);
    }
  }

  /**
   * This class should be never be instantiated; this just ensures so.
   */
  private BrowserUtil() {
  }

  /**
   * Attempts to open the default web browser to the given URL.
   * 
   * @param url
   *          The URL to open
   * @throws IOException
   *           If the web browser could not be located or does not run
   */
  public static Process openUrlInDefaultBrowser(String url) throws IOException {

    Process process = null;

    switch (__osId) {
      case WINDOWS_NT:
      case WINDOWS_9x:
        // Add quotes around the URL to allow ampersands and other
        // special characters to work.
        process = Runtime.getRuntime().exec(
                new String[] { __browserLauncher, FIRST_WINDOWS_PARAMETER,
                    SECOND_WINDOWS_PARAMETER, THIRD_WINDOWS_PARAMETER, '"' + url + '"' });
        // This avoids a memory leak on some versions of Java on
        // Windows. That's hinted at in
        // <http://developer.java.sun.com/developer/qow/archive/68/>.
        try {
          process.waitFor();
          process.exitValue();
        } catch (InterruptedException ie) {
          throw new IOException("InterruptedException while launching browser: " + ie.getMessage());
        }
        break;
      case LINUX:
        // Assume that Mozilla is installed
        // First, attempt to open the URL in a currently running
        // session of Mozilla
        process = Runtime.getRuntime().exec(
                new String[] { __browserLauncher, MOZILLA_REMOTE_PARAMETER,
                    MOZILLA_OPEN_PARAMETER_START + url + MOZILLA_OPEN_PARAMETER_END });
        try {
          int exitCode = process.waitFor();
          if (exitCode != 0) {
            // Mozilla was not open
            // Try opening new browser window
            process = Runtime.getRuntime().exec(new String[] { __browserLauncher, url });
            /*
             * // Attempt to open the URL using 'default' Mozilla // profile process =
             * Runtime.getRuntime().exec( new String[] { (String)browser, MOZILLA_PROFILE_OPTION,
             * MOZILLA_DEFAULT_PROFILE, url } );
             */
          }
        } catch (InterruptedException ie) {
          throw new IOException("InterruptedException while launching browser: " + ie.getMessage());
        }
        break;
      case OTHER:
        // Assume that we're on Unix and that Netscape is installed
        // First, attempt to open the URL in a currently running
        // session of Netscape
        process = Runtime.getRuntime().exec(
                new String[] { __browserLauncher, NETSCAPE_REMOTE_PARAMETER,
                    NETSCAPE_OPEN_PARAMETER_START + url + NETSCAPE_OPEN_PARAMETER_END });
        try {
          int exitCode = process.waitFor();
          if (exitCode != 0) { // if Netscape was not open
            Runtime.getRuntime().exec(new String[] { __browserLauncher, url });
          }
        } catch (InterruptedException ie) {
          throw new IOException("InterruptedException while launching browser: " + ie.getMessage());
        }
        break;
      default:
        // This should never occur, but if it does, we'll try the
        // simplest thing possible
        process = Runtime.getRuntime().exec(new String[] { __browserLauncher, url });
        break;
    }
    return process;
  }
}