Java 文档注释
Java文档注释
Java文档注释是用于描述Java代码的标准注释格式,能够自动提取出代码中的文档信息并生成文档页面。这种注释经常出现在开源Java代码中,并广泛应用于Java程序员之间的协作。
注释格式
Java文档注释的格式非常简单,以/**
开头,*/
结尾,中间可以添加多个*
,同时具有高度的可自定义性,下面是一个常见的Java文档注释格式的例子:
/**
* The Main class of this Hello World Program.
* It will print "Hello, World!" when run.
*/
public class Main {
/**
* This is the main method of the program.
* @param args The command line arguments.
*/
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}
Java文档注释有几个特点:
- 要放在被注释方法或者变量的上方
- 以"/**“开头,”*/“结尾
- 要用”@“符号标注变量或方法的含义
- 注释要以英文写作,避免中文注释
具体内容,我们将在下面继续解释。
注释内容
Java文档注释中可以添加很多内容,以帮助开发人员更好的了解代码意图。在实际应用中,大部分Java文档注释都包含以下内容:
代码示例
Java文档注释中可以添加代码示例,用于展现被注释方法或者变量的正确使用方法。如下面例子展示:
/**
* A class representing a book.
* @version 1.0
*/
public class Book {
private String title; // The title of the book.
private String author; // The author of the book.
/**
* Creates a new Book object with the specified title and author.
* @param title The title of the book.
* @param author The author of the book.
*/
public Book(String title, String author) {
this.title = title;
this.author = author;
}
/**
* Returns the title of the book.
* @return The title of the book.
* @example "The Great Gatsby", "1984"
*/
public String getTitle() {
return title;
}
/**
* Returns the author of the book.
* @return The author of the book.
* @example "F. Scott Fitzgerald", "George Orwell"
*/
public String getAuthor() {
return author;
}
}
参数说明
Java文档注释可以用@param
标签来标注方法或者函数的参数说明。如下面的例子:
/**
* This is a method to calculate the area of a rectangle.
* @param width The width of the rectangle.
* @param height The height of the rectangle.
* @return The area of the rectangle.
*/
public int getArea(int width, int height) {
return width * height;
}
返回值说明
Java文档注释可以用@return
标签来标注带有返回值的函数的返回值说明。如:
/**
* This is a method to calculate the area of a rectangle.
* @param width The width of the rectangle.
* @param height The height of the rectangle.
* @return The area of the rectangle.
*/
public int getArea(int width, int height) {
return width * height;
}
异常说明
Java文档注释可以用@throws
标签来标注函数抛出的异常。如:
/**
* This method may throw an IllegalArgumentException if the input string is null.
* @param input A string to check.
* @throws IllegalArgumentException if the input string is null.
*/
public void test(String input) throws IllegalArgumentException {
if(input == null) {
throw new IllegalArgumentException("The input string cannot be null.");
}
}
其他信息
Java文档注释还可以包含其他类型的信息,比如作者,创建日期,版本号等等。我们通常使用@author
标签:
/**
* The Main class of this Hello World Program.
* It will print "Hello, World!" when run.
* @author John
*/
public class Main {
/**
* This is the main method of the program.
* @param args The command line arguments.
*/
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}
同时,可以用@version
标签表示版本号:
/**
* A class representing a book.
* @version 1.0
*/
public class Book {
private String title; // The title of the book.
private String author; // The author of the book.
/**
* Creates a new Book object with the specified title and author.
* @param title The title of the book.
* @param author The author of the book.
*/
public Book(String title, String author) {
this.title = title;
this.author = author;
}
/**
* Returns the title of the book.
* @return The title of the book.
* @example "The Great Gatsby", "1984"
*/
public String getTitle() {
return title;
}
/**
* Returns the author of the book.
* @return The author of the book.
* @example "F. Scott Fitzgerald", "George Orwell"
*/
public String getAuthor() {
return author;
}
}
总结
通过这篇技术文档,我们深入了解了Java文档注释的格式和内容,深入理解Java文档注释的重要性和优越性。Java文档注释可以增进代码的可读性和协作性,同时也为代码的后续维护和升级提供了良好的保障,是我们工作中必须掌握的一项高级技能。