Springboot通过拦截器拦截请求信息收集到日志

1、需求

最近在工作中遇到的一个需求，将请求中的客户端类型、操作系统类型、ip、port、请求方式、URI以及请求参数值收集到日志中，网上找资料说用拦截器拦截所有请求然后收集信息，于是就开始了操作：

2、问题

试了之后发现当请求方式为POST，前端发送数据json时只能用request.getReader()流获取，自信满满从流中获取之后发现请求之后报错：

getInputStream() has already been called for this request...

于是网上找答案，发现是ServletRequest的getReader()和getInputStream()两个方法只能被调用一次，而且不能两个都调用。那么如果Filter中调用了一次，在Controller里面就不能再调用了。

然后又开始找解决方法，说既然ServletInputStream不支持重新读写，就把流读出来后用容器存储起来，后面就可以多次利用了。

于是继承 HttpServletRequestWrapper类（http请求包装器，其基于装饰者模式实现了HttpServletRequest界面）并实现想要重新定义的方法以达到包装原生HttpServletRequest对象。还需要在过滤器里将原生的HttpServletRequest对象替换成我们的RequestWrapper对象。

测试发现POST请求参数值可以在拦截器类中获取到了，本以为大功告成，又发现GET请求不好使了，开始报错Stream closed，一顿操作发现需要在过滤器进行判断，如果是POST请求走自己的继承的HttpServletRequestWrapper类请求，否则走普通的请求。终于成功！突然舒服了。

2、获取

1）导入依赖为了获取客户端类型、操作系统类型、ip、port：

<dependency>
            <groupId>eu.bitwalker</groupId>
            <artifactId>UserAgentUtils</artifactId>
            <version>1.21</version>
</dependency>

2）封装获取body字符串的工具类

package com.btrc.access.util;

import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;

public class RequestUtil {
    public static String getBodyString(HttpServletRequest request) {
        StringBuilder sb = new StringBuilder();
        try (
                InputStream inputStream = request.getInputStream();
               BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName("UTF-8")))
        ) {
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return sb.toString();
    }
}

3）拦截器类

package com.btrc.access.filter;

import com.btrc.access.util.RequestUtil;
import eu.bitwalker.useragentutils.UserAgent;
import org.apache.commons.lang.StringUtils;
import org.springframework.http.HttpMethod;
import org.springframework.web.servlet.HandlerInterceptor;

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

/**
 * 请求拦截器：拦截请求目的是将请求的信息收集到日志
 */
public class RequestInterceptor implements HandlerInterceptor {

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

        UserAgent userAgent = UserAgent.parseUserAgentString(request.getHeader("user-agent"));
        //客户端类型
        String clientType = userAgent.getOperatingSystem().getDeviceType().getName();
        //客户端操作系统类型
        String osType = userAgent.getOperatingSystem().getName();
        //客户端ip
        String clientIp = request.getRemoteAddr();
        //客户端port
        int clientPort = request.getRemotePort();
        //请求方式
        String requestMethod = request.getMethod();
        //客户端请求URI
        String requestURI = request.getRequestURI();
        //客户端请求参数值
        String requestParam;
        //如果请求是POST获取body字符串，否则GET的话用request.getQueryString()获取参数值
        if(StringUtils.equalsIgnoreCase(HttpMethod.POST.name(), requestMethod)){
            requestParam = RequestUtil.getBodyString(request);
        }else{
            requestParam = request.getQueryString();
        }
        //客户端整体请求信息
        StringBuilder clientInfo = new StringBuilder();
        clientInfo.append("客户端信息:[类型:").append(clientType)
                .append(", 操作系统类型:").append(osType)
                .append(", ip:").append(clientIp)
                .append(", port:").append(clientPort)
                .append(", 请求方式:").append(requestMethod)
                .append(", URI:").append(requestURI)
                .append(", 请求参数值:").append(requestParam.replaceAll("\\s*", ""))
                .append("]");

        //***这里的clientInfo就是所有信息了，请根据自己的日志框架进行收集***
        System.out.println(clientInfo);

		//返回ture才会继续执行，否则一直拦截住
        return true;
    }
}

4）继承 HttpServletRequestWrapper类

package com.btrc.access.filter;

import com.btrc.access.util.RequestUtil;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
import java.nio.charset.Charset;

public class AccessRequestWrapper extends HttpServletRequestWrapper {
    private final byte[] body;

    public AccessRequestWrapper(HttpServletRequest request) {
        super(request);
        body = RequestUtil.getBodyString(request).getBytes(Charset.forName("UTF-8"));
    }

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {

        final ByteArrayInputStream bais = new ByteArrayInputStream(body);

        return new ServletInputStream() {

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

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

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

            @Override
            public void setReadListener(ReadListener readListener) {

            }
        };
    }
}

5）过滤器类

package com.btrc.access.filter;

import org.apache.commons.lang.StringUtils;
import org.springframework.http.HttpMethod;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class AccessFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        //如果是POST走自己的继承的HttpServletRequestWrapper类请求，否则走正常的请求
        if(StringUtils.equalsIgnoreCase(HttpMethod.POST.name(), request.getMethod())){
            //一定要在判断中new对象，否则还会出现Stream closed问题
            filterChain.doFilter(new AccessRequestWrapper(request),servletResponse);
        }else{
            filterChain.doFilter(servletRequest,servletResponse);
        }
    }

    @Override
    public void destroy() {

    }
}

6）拦截器过滤器配置类

package com.btrc.access.config;

import com.btrc.access.filter.AccessFilter;
import com.btrc.access.filter.RequestInterceptor;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import javax.servlet.Filter;

/**
 * 拦截器过滤器配置类
 */
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Bean
    public FilterRegistrationBean httpServletRequestReplacedFilter() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(new AccessFilter());
        // /* 是全部的请求拦截，和Interceptor的拦截地址/**区别开
        registration.addUrlPatterns("/*");
        registration.setName("accessRequestFilter");
        registration.setOrder(1);
        return registration;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new RequestInterceptor()).addPathPatterns("/**");
    }
}