Java 注释格式
1 注释文档的格式
注释文档将用来生成HTML格式的代码报告，所以注释文档必须书写在类、域、构造函数、方法、定义之前。注释文档由两部分组成——描述、块标记。 例如：
/**
* The doGet method of the servlet.
* This method is called when a form has its tag value method equals to get.
*
* @param request
* the request send by the client to the server
* @param response
* the response send by the server to the client
* @throws ServletException
* if an error occurred
* @throws IOException
* if an error occurred
*/
public void doGet (HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
前两行为描述，描述完毕后，由@符号起头为块标记注视。
2 注释的种类
2.1 文件头注释
文件头注释以 /*开始，以*/结束，需要注明该文件创建时间，文件名，命名空间信息。
例如：
/*
* Created on 2005-7-2
* /
2.2 类、接口注释
类、接口的注释采用 /** … */，描述部分用来书写该类的作用或者相关信息，块标记部分必须注明作者和版本。
例如：
/**Title: XXXX DRIVER 3.0
*Description: XXXX DRIVER 3.0
*Copyright: Copyright (c) 2003
*Company:XXXX有限公司
*
* @author Java Development Group
* @version 3.0
*/
例如：
/**
* A class representing a window on the screen.
* For example:
*
* Window win = new Window(parent);
* win.show();
*
*
* @author Sami Shaio
* @version %I%, %G%
* @see java.awt.BaseWindow
* @see java.awt.Button
*/
class Window extends BaseWindow {
...
}
2.3 构造函数注释
构造函数注释采用 /** … */，描述部分注明构造函数的作用，不一定有块标记部分。
例如：
/**
* 默认构造函数
*/
有例如：
/**
* 带参数构造函数,初始化模式名,名称和数据源类型
*
* @param schema
* Ref 模式名
* @param name
* Ref 名称
* @param type
* byVal 数据源类型
*/
2.4 域注释
域注释可以出现在注释文档里面，也可以不出现在注释文档里面。用/** … */的域注释将会被认为是注释文档热出现在最终生成的HTML报告里面，而使用/* … */的注释会被忽略。
例如：
/* 由于triger和表用一个DMSource，所以要区分和表的迁移成功标记 */ boolean isTrigerSuccess = false;
又例如：
/** 由于triger和表用一个DMSource，所以要区分和表的迁移成功标记 */ boolean isTrigerSuccess = false;
再例如：
/**
* The X-coordinate of the component.
*
* @see #getLocation()
*/
int x = 1263732;
2.5 方法注释
方法注释采用 /** … */，描述部分注明方法的功能，块标记部分注明方法的参数，返回值，异常等信息。例如：
/**
* 设置是否有外码约束
*
* @param conn
* Connection 与数据库的连接
*/
2.6 定义注释
规则同域注释。
3 注释块标记
3.1 标记的顺序
块标记将采用如下顺序：
…
*
* @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. See footnote 1) * @see
* @since
* @serial (or @serialField or @serialData)
* @deprecated (see How and When To Deprecate APIs)
* …
一个块标记可以根据需要重复出现多次，多次出现的标记按照如下顺序： @author 按照时间先后顺序（chronological）
@param 按照参数定义顺序（declaration）
@throws 按照异常名字的字母顺序（alphabetically）
@see 按照如下顺序：
@see #field
@see #Constructor(Type, Type...)
@see #Constructor(Type id, Type id...)
@see #method(Type, Type,...)
@see #method(Type id, Type, id...)
@see Class
@see Class#field
@see Class#Constructor(Type, Type...)
@see Class#Constructor(Type id, Type id)
@see Class#method(Type, Type,...)
@see Class#method(Type id, Type id,...)
@see package.Class
@see package.Class#field
@see package.Class#Constructor(Type, Type...)
@see package.Class#Constructor(Type id, Type id)
@see package.Class#method(Type, Type,...)
@see package.Class#method(Type id, Type, id)
@see package
3.2 标记介绍
3.2.1 @param标记
@param后面空格后跟着参数的变量名字（不是类型），空格后跟着对该参数的描述。
在描述中第一个名字为该变量的数据类型，表示数据类型的名次前面可以有一个冠词如：a,an,the。如果是int类型的参数则不需要注明数据类型。例如： …
* @param ch the char 用用来……
* @param _image the image 用来……
* @param _num 一个数字……
…
对于参数的描述如果只是一短语，最好不要首字母大写，结尾也不要句号。 对于参数的描述是一个句子，最好不要首字母大写，如果出现了句号这说明你的描述不止一句话。如果非要首字母大写的话，必须用句号来结束句子。（英文的句号）
公司内部添加ByRef和ByVal两个标记，例如：
* @param _image the image ByRef 用来……
说明该参数是引用传递（指针），ByVal可以省略，表示是值传递。
3.2.2 @return标记
返回为空（void）的构造函数或者函数，@return可以省略。
如果返回值就是输入参数，必须用与输入参数的@param相同的描述信息。 必要的时候注明特殊条件写的返回值。
3.2.3 @throws 标记
@throws以前使用的是@exception。
@throws的内容必须在函数的throws部分定义。
3.2.4 @author标记
类注释标记。
函数注释里面可以不出现@author。
3.2.5 @version
类注释标记。
函数注释里面可以不出现@version
3.2.6 @since
类注释标记。
标明该类可以运行的JDK版本
例如：
@since JDK1.2
3.2.7 @deprecated
由于某种原因而被宣布将要被废弃的方法。
/**
* @deprecated As of JDK 1.1, replaced by
* setBounds
* @see #setBounds(int,int,int,int)
*/
3.2.8 @link标记
语法：{@link package.class#member label}
Label为链接文字。
package.class#member将被自动转换成指向package.class的member文件的URL。
4 HTML代码的使用
在注释描述部分可以使用HTML代码。
表示段落
表示自动标号
5 注释示例
/**
* 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:
*
*
*
*
*
*
*
*
* (see setXORMode)
*
*
* 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. *
* 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.
*
* 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.
*
* 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
* null
* @return true if the image is completely
* loaded and was painted successfully;
* false 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. *
* 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();
}
}