JDK中常见注解简介说明

JDK中常用的几个注解如下所示:
    @Override注解
	@Deprecated注解
    @SuppressWarnings

@Override注解:功能为:重写

public class OverrideTest{
    @Override
    public String toString(){
        return "方法被重写！";
    }
    public static void main(String[] args){
        OverrideTest test = new OverrideTest();
        System.out.println(test);
    }
}

@Deprecated注解:标记方法过时(不建议被使用)

public class DeprecatedTest{
    @Deprecated
    public void doSomething(){
        System.out.println("方法被运行！");
    }
    public static void main(String[] args){
        DeprecatedTest test = new DeprecatedTest();
        test.doSomething();
        Date date = new Date();
        System.out.println(date.toLocaleString());
    }
}

@SuppressWarnings({"unchecked", "deprecation"})注解
表示压制警告

import java.util.Date;
import java.util.Map;
import java.util.TreeMap;
public class SuppressWarningsTest{
    @SuppressWarnings({"unchecked", "deprecation"})
    public static void main(String[] args){
        Map map = new TreeMap();
        map.put("hello", new Date());
        System.out.println(map.get("hello"));
        Date date = new Date();
        System.out.println(date.toLocaleString());
    }
}