什么是package-info
在java项目中创建package以后,可以在package下放一个package-info.java文件。
这个文件有什么作用?如何生成?
三个作用:
-
为标注在包上Annotation提供便利;
package annotations -
声明友好类和包常量;
比如一个包中有很多的内部访问的类或常量,就可以统一的放到package-info类中,这样就方便,而且集中管理,减少friendly类到处游走的情况,看例子:
//这里是包类,声明一个包使用的公共类,强调的是包访问权限
class PkgClass{
public void test(){
}
}
//包常量,只运行包内访问,适用于分“包”开发
class PkgConst{
static final String PACAKGE_CONST="ABC";
}
- 提供包的整体注释说明。
Package Documentation
Prior to Java 5, package level documentation (the documentation shown in Javadocs for a package) was placed in package.html. Today, the description and other related documentation for a package can be written up in the package-info.java file and it gets used in the production of the Javadocs. As a demonstration, the example package-info.java…
/**
* Domain classes used to produce the JSON and XML output for the RESTful services.
* <p>
* These classes contain the JAXB annotations.
*
* @since 1.0
* @author jwhite
* @version 1.1
*/
package com.intertech.cms.domain;
package documentation… results in the following Javadocs.
package-info.java’s purpose
The package-info.java is a Java file that can be added to any Java source package. Its purpose is to provide a home for package level documentation and package level annotations. Simply create the package-info.java file and add the package declaration that it relates to in the file. In fact, the only thing the package-info.java file must contain is the package declaration.
- 如何创建:
参考