Java通过反射获取自定义注解

Java通过反射获取自定义注解

• 需要的几个jar包
  1.reflections-0.9.10.jar 反射包
  2.guava-15.0.jar 反射的依赖包
  3.javassist-3.18.2-GA.jar 反射的依赖包

• 自定义注解类

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Controller {
    String value() default "/";
}

• 测试类1

@Controller("/test1")
public class Test1 {

}

• 测试类2

@Controller("test2")
public class Test2 {

}

• 测试类3

@Controller("/test3")
public class Test3 {

}

• 整体功能代码

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import org.reflections.Reflections;

public class AnnotationTest {
    private static final String CONTROLLER_PACK = "com.lzy.*";

    public static void main(String[] args) {
        Map map = getControllerAnnotation();
        for (Map.Entry m : map.entrySet()) {
            System.out.println("Value:" + m.getKey() + "----" + "Class:" + m.getValue());
        }
    }

    /**
     * 获取注解的controller
     * 
     * @return
     */
    @SuppressWarnings("rawtypes")
    public static Map getControllerAnnotation() {
        Map result = new HashMap();
        //指定反射扫描包
        Reflections reflections = new Reflections(CONTROLLER_PACK);
        //获取注解类型的set集合数据
        Set> classes = reflections.getTypesAnnotatedWith(Controller.class);
        //存储到结果集
        for (Class clazz : classes) {
            Controller controller = (Controller) clazz.getAnnotation(Controller.class);
            String value = controller.value();
            result.put(value, clazz);
        }
        return result;
    }
}

• 运行结果