java中输出自定义注解的实际内容
关于java自定义anootation的介绍见:http://jackyrong.iteye.com/blog/1900712
这里的一个例子,是输出一个使用了java自定义注解的实际内容的例子:
上面是一个注解,接下来是使用上面的注解:
再来一个测试类,要输入这个类到底使用的是注解的什么属性以及其值:
这里的一个例子,是输出一个使用了java自定义注解的实际内容的例子:
@Retention(RetentionPolicy.RUNTIME)
public @interface DeveloperInfo {
String date();
String name();
String title();
String version();
}
上面是一个注解,接下来是使用上面的注解:
@DeveloperInfo(name = "A Random Coder", title = "King Lazy", date = "2010/10/01",
version = "1.0")
@SuppressWarnings("all") //this is here for a reason <img class="wp-smiley" alt=";-)" src="http://reegz.co.za/wp-includes/images/smilies/icon_wink.gif">
public class ARandomClass {
public void aRandomMethod() {
// Some very random code...
}
@DeveloperInfo(name = "Joe Dirt", title = "Codename: The Cleaner",
date = "2010/09/01", version = "1.0")
public void doSomeRealWork() {
// Some real code here...
}
}
再来一个测试类,要输入这个类到底使用的是注解的什么属性以及其值:
public class AnnotationTest {
@SuppressWarnings("unchecked")
public static void main(String[] args) {
// An instance of the class which uses the annotation.
ARandomClass aRandomClass = new ARandomClass();
Class clazz = aRandomClass.getClass();
for (Annotation annotation : clazz.getAnnotations()) {
System.out.printf("Class-level annotation of type: %1$s n", annotation.annotationType());
}
try {
Method[] methods = clazz.getMethods();
for (Method method : methods) {
DeveloperInfo info = method.getAnnotation(DeveloperInfo.class);
if (info != null) {
System.out.printf("Method %1$s contains the DeveloperInfo annotation.n",
method.getName());
printAnnotationInfo(info);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Outputs the data stored in the annotation.
*
* @param info
*/
private static void printAnnotationInfo(DeveloperInfo info) {
System.out.printf("tName: %1$s, Title:%2$s, Date:%3$s, Version:%4$sn",
info.name(), info.title(), info.date(), info.version());
}
}