Java

SpringMVC - 使用 Filter 统一打请求日志

继续后端服务系列：

使用 Filter 统一打日志。Filter 其实来自 javax.servlet.Filter，是在 Servlet 规范中定义的，是 Servlet 容器支持的。

效果如下：

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[23:42:05:223] [INFO] - com.tracenote.filters.RequestBodyReaderWrapper.writeLog(RequestBodyReaderWrapper.java:29) - {    "name": "zhang"}

实现：

web.xml 配置

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<filter>
    <filter-name>RequestFilter</filter-name>
    <filter-class>com.tracenote.filters.RequestFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>RequestFilter</filter-name>
    <url-pattern>*</url-pattern>
</filter-mapping>
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package com.tracenote.filters;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;


public class RequestFilter implements Filter {
    private static Logger logger = LoggerFactory.getLogger(RequestFilter.class);

    @Override
    public void destroy() {

    }

    public void init(FilterConfig filterConfig) {

    }

    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain) throws ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        try {
            RequestBodyReaderWrapper myRequest = new RequestBodyReaderWrapper(req);
            chain.doFilter(myRequest, response);
        } catch (Exception e) {
            logger.error(e.toString());
        }
    }
}
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package com.tracenote.filters;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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

public class RequestBodyReaderWrapper extends HttpServletRequestWrapper {
    private static Logger logger = LoggerFactory.getLogger(RequestBodyReaderWrapper.class);
    private final byte[] body;

    public RequestBodyReaderWrapper(HttpServletRequest request) throws Exception {
        super(request);
        body = writeLog(request).getBytes();
    }

    private static String writeLog(HttpServletRequest request) throws Exception {
        InputStream inputStream = request.getInputStream();
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        String msg = "";
        StringBuilder sb = new StringBuilder();
        while ((msg = reader.readLine()) != null) {
            sb.append(msg);
        }
        logger.info(sb.toString());
        return sb.toString();
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body);
        return new ServletInputStream() {
            @Override
            public int read() throws IOException {
                return byteArrayInputStream.read();
            }

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

            @Override
            public void setReadListener(ReadListener readListener) {

            }

            public boolean isFinished() {
                return byteArrayInputStream.available() == 0;
            }
        };
    }

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

参考：