Springboot通过filter修改body参数思路

知识点

　　1、HttpServletRequestWrapper

　　2、filter

步骤:

　　1、新建MyHttpServletRequestWrapper继承HttpServletRequestWrapper

　　2、讲传入的body赋值给自己的body（如下）

package com.orisdom.modules.common.filter;


import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.orisdom.modules.monitor.dto.input.MonitorPointQueryPara;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;

/**
 * @author xiaokang
 * @description
 * @date 2021/6/11 10:56
 */
public class MyHttpServletRequestWrapper extends HttpServletRequestWrapper {

    private String tempBody;

    public MyHttpServletRequestWrapper(HttpServletRequest request) {
        super(request);
        this.tempBody = getBody(request);
        System.out.println(tempBody);

    }
    /**
     * 获取请求体
     * @param request 请求
     * @return 请求体
     */
    private String getBody(HttpServletRequest request) {
        try {
            ServletInputStream stream = request.getInputStream();
            String read = "";
            StringBuilder stringBuilder = new StringBuilder();
            byte[] b = new byte[1024];
            int lens = -1;
            while ((lens = stream.read(b)) > 0) {
                stringBuilder.append(new String(b, 0, lens));
            }
            return stringBuilder.toString();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
    /**
     * 获取请求体
     * @return 请求体
     */
    public String getBody() {
        MonitorPointQueryPara para = JSON.parseObject(tempBody, MonitorPointQueryPara.class);
        para.setName("1232321321");
        tempBody = JSONObject.toJSONString(para);
        return tempBody;
    }

    /**
     * 需要重写这个方法
     * @return
     * @throws IOException
     */
    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }
    /**
     * 需要重写这个方法
     * @return
     * @throws IOException
     */
    @Override
    public ServletInputStream getInputStream() throws IOException {
        // 创建字节数组输入流
        final ByteArrayInputStream bais = new ByteArrayInputStream(tempBody.getBytes(Charset.defaultCharset()));

        return new ServletInputStream() {
            @Override
            public boolean isFinished() {
                return false;
            }

            @Override
            public boolean isReady() {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {

            }

            @Override
            public int read() throws IOException {
                return bais.read();
            }
        };
    }
}

1.新建MyFilter 继承 Filter
2.添加@WebFilter注解
3.启动类添加@ServletComponentScan(如下)

package com.orisdom.modules.common.filter;

import org.springframework.core.annotation.Order;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * @author xiaokang
 * @description
 * @date 2021/6/11 9:47
 */
@WebFilter
public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
　　　　
        MyHttpServletRequestWrapper myHttpServletRequestWrapper = new MyHttpServletRequestWrapper((HttpServletRequest) servletRequest);
　　　　　// 相当于赋值
        myHttpServletRequestWrapper.getBody();
　　　　　// 自己定义的MyHttpServletRequestWrapper
        filterChain.doFilter(myHttpServletRequestWrapper, servletResponse);
        System.out.println(11111111);
    }

    @Override
    public void destroy() {

    }
}

  没加之前

 加了之后