Java代码注释规范(From Sun MicroSystem)

在软件开发中，文档和代码的管理是很重要的，Java中采用了一个很好JavaDoc机制很好把文档和代码连接了起来。只要你的代码是按照规范写的，那么就可以用Tools来生成如Java API Docs那样的HTML文档，很方便查阅、管理。

以前写代码很注意代码的风格和注释，但是没有按照具体的规范写，只是按照有些参考书上的样子和自己的想法来写，虽然已经感觉很好了，但是当在Sun的主页上看到这个规范后，自己的一些缺点就暴露出来了。下面就把这个规范上的东西做一个总结：

注释的第一步写是描述，这个对于类、成员、接口、包都是一样的。
注释标记的顺序如下：

* @param       (classes, interfaces, methods and constructors only)
* @return      (methods only)
* @exception   (@throws is a synonym added in Javadoc 1.2)
* @author      (classes and interfaces only, required)
* @version     (classes and interfaces only, required. Seefootnote 1)
* @see
* @since
* @serial      (or @serialField or @serialData)
* @deprecated  (seeHow and When To Deprecate APIs)
下面给出一个比较完整的例子：
/**
* Graphics is the abstract base class for all graphics contexts
* which allow an application to draw onto components realized on
* various devices or onto off-screen images.
* A Graphics object encapsulates the state information needed
* for the various rendering operations that Java supports.  This
* state information includes:
* <ul>
* <li>The Component to draw on
* <li>A translation origin for rendering and clipping coordinates
* <li>The current clip
* <li>The current color
* <li>The current font
* <li>The current logical pixel operation function (XOR or Paint)
* <li>The current XOR alternation color
*     (see <a href="#setXORMode">setXORMode</a>)
* </ul>
* <p>
* Coordinates are infinitely thin and lie between the pixels of the
* output device.
* Operations which draw the outline of a figure operate by traversing
* along the infinitely thin path with a pixel-sized pen that hangs
* down and to the right of the anchor point on the path.
* Operations which fill a figure operate by filling the interior
* of the infinitely thin path.
* Operations which render horizontal text render the ascending
* portion of the characters entirely above the baseline coordinate.
* <p>
* Some important points to consider are that drawing a figure that
* covers a given rectangle will occupy one extra row of pixels on
* the right and bottom edges compared to filling a figure that is
* bounded by that same rectangle.
* Also, drawing a horizontal line along the same y coordinate as
* the baseline of a line of text will draw the line entirely below
* the text except for any descenders.
* Both of these properties are due to the pen hanging down and to
* the right from the path that it traverses.
* <p>
* All coordinates which appear as arguments to the methods of this
* Graphics object are considered relative to the translation origin
* of this Graphics object prior to the invocation of the method.
* All rendering operations modify only pixels which lie within the
* area bounded by both the current clip of the graphics context
* and the extents of the Component used to create the Graphics object.
*
* @author      Sami Shaio
* @author      Arthur van Hoff
* @version     %I%, %G%
* @since       1.0
*/
public abstract class Graphics {

/**
* Draws as much of the specified image as is currently available
* with its northwest corner at the specified coordinate (x, y).
* This method will return immediately in all cases, even if the
* entire image has not yet been scaled, dithered and converted
* for the current output device.
* <p>
* If the current output representation is not yet complete then
* the method will return false and the indicated
* {@link ImageObserver} object will be notified as the
* conversion process progresses.
*
* @param img       the image to be drawn
* @param x         the x-coordinate of the northwest corner
*                  of the destination rectangle in pixels
* @param y         the y-coordinate of the northwest corner
*                  of the destination rectangle in pixels
* @param observer  the image observer to be notified as more
*                  of the image is converted.  May be
*                  <code>null</code>
* @return          <code>true</code> if the image is completely
*                  loaded and was painted successfully;
*                  <code>false</code> otherwise.
* @see             Image
* @see             ImageObserver
* @since           1.0
*/
public abstract boolean drawImage(Image img, int x, int y,
ImageObserver observer);

/**
* Dispose of the system resources used by this graphics context.
* The Graphics context cannot be used after being disposed of.
* While the finalization process of the garbage collector will
* also dispose of the same system resources, due to the number
* of Graphics objects that can be created in short time frames
* it is preferable to manually free the associated resources
* using this method rather than to rely on a finalization
* process which may not happen for a long period of time.
* <p>
* Graphics objects which are provided as arguments to the paint
* and update methods of Components are automatically disposed
* by the system when those methods return.  Programmers should,
* for efficiency, call the dispose method when finished using
* a Graphics object only if it was created directly from a
* Component or another Graphics object.
*
* @see       #create(int, int, int, int)
* @see       #finalize()
* @see       Component#getGraphics()
* @see       Component#paint(Graphics)
* @see       Component#update(Graphics)
* @since     1.0
*/
public abstract void dispose();

/**
* Disposes of this graphics context once it is no longer
* referenced.
*
* @see       #dispose()
* @since     1.0
*/
public void finalize() {
dispose();
}
}

有了上面的例子就可以对Java中的注释大概掌握了，以后的问题就是你在现实的编程中加以运用就可以了。