自定义注解拦截器

1.先自定义注解

如下所示,我们先自定义好注解，自定义注解往往需要定义该注解使用在什么地方，什么时间使用它

@Target(ElementType.METHOD)//此处定义为方法级注解
@Retention(RetentionPolicy.RUNTIME)//表示运行的时候使用该注解
@Documented//生成javadoc的时候就会把@Documented注解给显示出来。
public @interface Login {
}

如下所示

ackage com.irving.ir.config;

import com.irving.ir.common.util.JwtUtils;
import com.irving.ir.componet.AuthorizationInterceptor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * @author irving
 * @date 2021/6/19
 */
@Configuration
public class WebConfig implements WebMvcConfigurer {

   
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new AuthorizationInterceptor());
    }
}

如下

package com.irving.ir.componet;


import com.irving.ir.common.annotation.Login;

import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;


import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


/**
 * 自定义token处理逻辑
 * @author irving
 * @date 2021/6/19
 */

public class AuthorizationInterceptor extends HandlerInterceptorAdapter {


   
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        Login annotation;

        if (handler instanceof HandlerMethod){

            annotation=((HandlerMethod)handler).getMethodAnnotation(Login.class);
        }else {
            return  true;
        }

        if (annotation==null){
            return true;
        }
        //具体需要拦截该注解的接口做什么操作
        ......
        
}

如下

    @ApiOperation("分页显示所有留言并按时间进行降序")
    @RequestMapping(value = "/list/all", method = RequestMethod.GET)
    @ResponseBody
    @Login
    public CommonResult<CommonPage<Board>> listBoard(@RequestParam(value = "pageNum",defaultValue = "1") Integer pageNum,
                                                     @RequestParam(value = "pageSize",defaultValue = "10")Integer pageSize){

        List<Board> boardList =boardService.queryAllBoard(pageNum,pageSize);
        return CommonResult.success(CommonPage.restPage(boardList),"分页查询成功");

    }