java知识点杂整理

1、@RestController

@RestController
 相当于@Controller+@ResponseBody两个注解的结合，返回json数据不需要在方法前面加@ResponseBody注解了，但使用@RestController这个注解，就不能返回jsp,html页面，视图解析器无法解析jsp,html页

@RestController
@RequestMapping("/test")
 
public class TestClassController {
    @GetMapping("/test")
    private String test(){
        System.out.println(hello);
        String yhz = environment.getProperty("hello");
        System.out.println(yhz);
        return yhz;
 
    }
}

2、@Anonymous

@Anonymous匿名访问不鉴权注解

3、forEach

    public AjaxResult addOrEdit(List<WechatMenu> menus) {
        menus.forEach(menu -> {
            if (ObjectUtils.isEmpty(menu.getId())) {
                menu.setAddTime(System.currentTimeMillis());
                menu.setCreateBy(SecurityUtils.getUsername());
                menu.setCreateTime(new Date());
                this.save(menu);
            } else {
                menu.setEditTime(System.currentTimeMillis());
                menu.setUpdateBy(SecurityUtils.getUsername());
                menu.setUpdateTime(new Date());
                this.updateById(menu);
            }
        });
        return AjaxResult.success();
    }

 

4、逻辑删除

<update id="deleteWechatReplayByReplayIds" parameterType="String">
        update wechat_replay set del_flag = 1 where replay_id in
        <foreach item="replayId" collection="array" open="(" separator="," close=")">
            #{replayId}
        </foreach>
    </update>

 

5、是否存在

    public boolean isExist(String mobile) {
        return ObjectUtils.isNotEmpty(this.getOne(new QueryWrapper<MobileBlacklist>().eq("mobile", mobile).or().eq("work_mobile", mobile)));
    }

6、rollbackFor

@Transactional(rollbackFor = Exception.class)

7、枚举类

import lombok.Getter;
@Getter
public enum WxEeventType {
    /**
     * 关注公众号
     */
    SUBSCRIBE("subscribe"),
    /**
     * 取消关注公众号
     */
    UNSUBSCRIBE("unsubscribe");

    private String code;
    WxEeventType(String code) {
        this.code = code;
    }
}

 

WxEeventType wxEeventType = WxEeventType.SUBSCRIBE.getCode().equals(subEvent) ? WxEeventType.SUBSCRIBE : WxEeventType.UNSUBSCRIBE;
      if (wxEeventType.getCode().equals("subscribe")){ }
　　　　else if (wxEeventType.getCode().equals("unsubscribe")){}