applet.java

《移动Agent技术》一书的所有章节源代码。

	    return null;
	}
    }

    /**
     * Returns the <code>AudioClip</code> object specified by the 
     * <code>URL</code> argument. 
     * <p>
     * This method always returns immediately, whether or not the audio 
     * clip exists. When this applet attempts to play the audio clip, the 
     * data will be loaded. 
     *
     * @param   url  an absolute URL giving the location of the audio clip.
     * @return  the audio clip at the specified URL.
     * @see     java.applet.AudioClip
     * @since   JDK1.0
     */
    public AudioClip getAudioClip(URL url) {
	return getAppletContext().getAudioClip(url);
    }

    /**
     * Returns the <code>AudioClip</code> object specified by the 
     * <code>URL</code> and <code>name</code> arguments. 
     * <p>
     * This method always returns immediately, whether or not the audio 
     * clip exists. When this applet attempts to play the audio clip, the 
     * data will be loaded. 
     * 
     * @param   url    an absolute URL giving the base location of the
     *                 audio clip.
     * @param   name   the location of the audio clip, relative to the
     *                 <code>url</code> argument.
     * @return  the audio clip at the specified URL.
     * @see     java.applet.AudioClip
     * @since   JDK1.0
     */
    public AudioClip getAudioClip(URL url, String name) {
	try {
	    return getAudioClip(new URL(url, name));
	} catch (MalformedURLException e) {
	    return null;
	}
    }

    /**
     * Returns information about this applet. An applet should override 
     * this method to return a <code>String</code> containing information 
     * about the author, version, and copyright of the applet. 
     * <p>
     * The implementation of this method provided by the 
     * <code>Applet</code> class returns <code>null</code>. 
     *
     * @return  a string containing information about the author, version, and
     *          copyright of the applet.
     * @since   JDK1.0
     */
    public String getAppletInfo() {
	return null;
    }

    /** 
     * Gets the Locale for the applet, if it has been set.
     * If no Locale has been set, then the default Locale 
     * is returned.
     *
     * @return  [Needs to be documented!]
     * @since   JDK1.1
     */

    public Locale getLocale() {
      Locale locale = super.getLocale();
      if (locale == null) {
	return Locale.getDefault();
      }
      return locale;
    }

    /**
     * Returns information about the parameters than are understood by 
     * this applet. An applet should override this method to return an 
     * array of <code>Strings</code> describing these parameters. 
     * <p>
     * Each element of the array should be a set of three 
     * <code>Strings</code> containing the name, the type, and a 
     * description. For example:
     * <p><blockquote><pre>
     * String pinfo[][] = {
     *	 {"fps",    "1-10",    "frames per second"},
     *	 {"repeat", "boolean", "repeat image loop"},
     *	 {"imgs",   "url",     "images directory"}
     * };
     * </pre></blockquote>
     * <p>
     * The implementation of this method provided by the 
     * <code>Applet</code> class returns <code>null</code>. 
     *
     * @return  an array describing the parameters this applet looks for.
     * @since   JDK1.0
     */
    public String[][] getParameterInfo() {
	return null;
    }

    /**
     * Plays the audio clip at the specified absolute URL. Nothing 
     * happens if the audio clip cannot be found. 
     *
     * @param   url   an absolute URL giving the location of the audio clip.
     * @since   JDK1.0
     */
    public void play(URL url) {
	AudioClip clip = getAudioClip(url);
	if (clip != null) {
	    clip.play();
	}
    }

    /**
     * Plays the audio clip given the URL and a specifier that is 
     * relative to it. Nothing happens if the audio clip cannot be found. 
     *
     * @param   url    an absolute URL giving the base location of the
     *                 audio clip.
     * @param   name   the location of the audio clip, relative to the
     *                 <code>url</code> argument.
     * @since   JDK1.0
     */
    public void play(URL url, String name) {
	AudioClip clip = getAudioClip(url, name);
	if (clip != null) {
	    clip.play();
	}
    }

    /**
     * Called by the browser or applet viewer to inform 
     * this applet that it has been loaded into the system. It is always 
     * called before the first time that the <code>start</code> method is 
     * called. 
     * <p>
     * A subclass of <code>Applet</code> should override this method if 
     * it has initialization to perform. For example, an applet with 
     * threads would use the <code>init</code> method to create the 
     * threads and the <code>destroy</code> method to kill them. 
     * <p>
     * The implementation of this method provided by the 
     * <code>Applet</code> class does nothing. 
     *
     * @see     java.applet.Applet#destroy()
     * @see     java.applet.Applet#start()
     * @see     java.applet.Applet#stop()
     * @since   JDK1.0
     */
    public void init() {
    }

    /**
     * Called by the browser or applet viewer to inform 
     * this applet that it should start its execution. It is called after 
     * the <code>init</code> method and each time the applet is revisited 
     * in a Web page. 
     * <p>
     * A subclass of <code>Applet</code> should override this method if 
     * it has any operation that it wants to perform each time the Web 
     * page containing it is visited. For example, an applet with 
     * animation might want to use the <code>start</code> method to 
     * resume animation, and the <code>stop</code> method to suspend the 
     * animation. 
     * <p>
     * The implementation of this method provided by the 
     * <code>Applet</code> class does nothing. 
     *
     * @see     java.applet.Applet#destroy()
     * @see     java.applet.Applet#init()
     * @see     java.applet.Applet#stop()
     * @since   JDK1.0
     */
    public void start() {
    }

    /**
     * Called by the browser or applet viewer to inform 
     * this applet that it should stop its execution. It is called when 
     * the Web page that contains this applet has been replaced by 
     * another page, and also just before the applet is to be destroyed. 
     * <p>
     * A subclass of <code>Applet</code> should override this method if 
     * it has any operation that it wants to perform each time the Web 
     * page containing it is no longer visible. For example, an applet 
     * with animation might want to use the <code>start</code> method to 
     * resume animation, and the <code>stop</code> method to suspend the 
     * animation. 
     * <p>
     * The implementation of this method provided by the 
     * <code>Applet</code> class does nothing. 
     *
     * @see     java.applet.Applet#destroy()
     * @see     java.applet.Applet#init()
     * @since   JDK1.0
     */
    public void stop() {
    }

    /**
     * Called by the browser or applet viewer to inform 
     * this applet that it is being reclaimed and that it should destroy 
     * any resources that it has allocated. The <code>stop</code> method 
     * will always be called before <code>destroy</code>. 
     * <p>
     * A subclass of <code>Applet</code> should override this method if 
     * it has any operation that it wants to perform before it is 
     * destroyed. For example, an applet with threads would use the 
     * <code>init</code> method to create the threads and the 
     * <code>destroy</code> method to kill them. 
     * <p>
     * The implementation of this method provided by the 
     * <code>Applet</code> class does nothing. 
     *
     * @see     java.applet.Applet#init()
     * @see     java.applet.Applet#start()
     * @see     java.applet.Applet#stop()
     * @since   JDK1.0
     */
    public void destroy() {
    }
}