自定义拦截器

案例描述

自定义拦截器，过滤前端传递的参数是否合法

实现思路

1. 添加自定义拦截器

2. 实现自定义参数过滤

操作步骤

1. 创建自定义拦截器MyCustomerFilter

package com.je.filter;

import com.je.core.base.JERequestWrapper;
import com.je.core.exception.PlatformException;
import com.je.core.exception.PlatformExceptionEnum;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.filter.OncePerRequestFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Map;


/**
 * 自定义过滤器
 */
public class MyCustomerFilter extends OncePerRequestFilter {

    private static final Logger logger = LoggerFactory.getLogger(MyCustomerFilter.class);

    private static final String[] STRS = new String[]{
            "1",
            "2",
            "3",
            "4"
    };

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        //请求路径
        String uri = request.getRequestURI();
        //前端传递的参数
        Map<String, String[]> parameters = request.getParameterMap();
        //包装Request
        JERequestWrapper requestWrapper = new JERequestWrapper(request);
        //是否合法
        Boolean isJustifiability = true;
        for (String str : parameters.keySet()) {
            //拿到参数值，进行校验
            String[] value = parameters.get(str);
            //自定义判断是否合法
            if (value 不合法){
                isJustifiability = false;
                break;
            }
        }
        if (!isJustifiability) {
            //可以自定义一个异常信息
            logger.info("参数不合法，url={}", uri);
            throw new PlatformException("参数不合法，url" + uri, PlatformExceptionEnum.UNKOWN_ERROR, new Object[]{uri, request.getParameterMap()});
        }
        //继续执行
        filterChain.doFilter(requestWrapper, response);
    }
}

2. 添加自定义拦截器配置
打开web.xml，添加自定义拦截器，一般自定义的拦截器需要添加到解密拦截器之后