SpringBoot利用Filter获取请求数据request和修改返回response中的数据

WrapperedRequest

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

public class WrapperedRequest extends HttpServletRequestWrapper {

    private String requestBody = null;
    HttpServletRequest req = null;

    public WrapperedRequest(HttpServletRequest request) {
        super(request);
        this.req = request;
    }

    public WrapperedRequest(HttpServletRequest request, String requestBody) {
        super(request);
        this.requestBody = requestBody;
        this.req = request;
    }

    /**
     * (non-Javadoc)
     *
     * @see javax.servlet.ServletRequestWrapper#getReader()
     */
    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new StringReader(requestBody));
    }

    /**
     * (non-Javadoc)
     *
     * @see javax.servlet.ServletRequestWrapper#getInputStream()
     */
    @Override
    public ServletInputStream getInputStream() throws IOException {
        return new ServletInputStream() {
            private InputStream in = new ByteArrayInputStream(
                    requestBody.getBytes(req.getCharacterEncoding()));

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

            @Override
            public boolean isFinished() {
                // TODO Auto-generated method stub
                return false;
            }

            @Override
            public boolean isReady() {
                // TODO Auto-generated method stub
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {
                // TODO Auto-generated method stub

            }
        };
    }
}

WrapperedResponse

import javax.servlet.ServletOutputStream;
import javax.servlet.WriteListener;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;

public class WrapperedResponse extends HttpServletResponseWrapper {

    private ByteArrayOutputStream buffer = null;
    private ServletOutputStream out = null;
    private PrintWriter writer = null;

    public WrapperedResponse(HttpServletResponse resp) throws IOException {
        super(resp);
        // 真正存储数据的流
        buffer = new ByteArrayOutputStream();
        out = new WapperedOutputStream(buffer);
        writer = new PrintWriter(new OutputStreamWriter(buffer, this.getCharacterEncoding()));
    }

    /**
     * 重载父类获取outputstream的方法
     */
    @Override
    public ServletOutputStream getOutputStream() throws IOException {
        return out;
    }

    /**
     * 重载父类获取writer的方法
     */
    @Override
    public PrintWriter getWriter() throws UnsupportedEncodingException {
        return writer;
    }

    /**
     * 重载父类获取flushBuffer的方法
     */
    @Override
    public void flushBuffer() throws IOException {
        if (out != null) {
            out.flush();
        }
        if (writer != null) {
            writer.flush();
        }
    }

    @Override
    public void reset() {
        buffer.reset();
    }

    /**
     * 将out、writer中的数据强制输出到WapperedResponse的buffer里面，否则取不到数据
     */
    public byte[] getResponseData() throws IOException {
        flushBuffer();
        return buffer.toByteArray();
    }

    /**
     * 内部类，对ServletOutputStream进行包装
     */
    private class WapperedOutputStream extends ServletOutputStream {
        private ByteArrayOutputStream bos = null;

        public WapperedOutputStream(ByteArrayOutputStream stream) throws IOException {
            bos = stream;
        }

        @Override
        public void write(int b) throws IOException {
            bos.write(b);
        }

        @Override
        public void write(byte[] b) throws IOException {
            bos.write(b, 0, b.length);
        }

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

        @Override
        public void setWriteListener(WriteListener writeListener) {

        }
    }
}

数据处理

import lombok.extern.slf4j.Slf4j;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.charset.StandardCharsets;

@Slf4j
public class DataFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain) throws IOException, ServletException {
        String contentType = request.getContentType();
        WrapperedResponse wrapResponse = new WrapperedResponse((HttpServletResponse) response);
        WrapperedRequest wrapRequest;
        // 表单请求数据自行处理解密
        if (contentType == null || !contentType.contains("multipart/form-data")) {
            String requestBody = getRequestBody((HttpServletRequest) request);
            log.info("请求数据：" + requestBody);
			// todo
            //处理请求报文
            String requestBodyStr =requestBody;
            wrapRequest = new WrapperedRequest((HttpServletRequest) request, requestBodyStr);
            chain.doFilter(wrapRequest, wrapResponse);
        } else {
            chain.doFilter(request, wrapResponse);
        }

        byte[] data = wrapResponse.getResponseData();
        String responseBody = new String(data, StandardCharsets.UTF_8);
        log.info("原始返回数据： " + responseBody);
        // 返回报文
        String responseBodyStr = responseBody;
        log.info("处理后返回数据： " + responseBodyStr);
        writeResponse(response, responseBodyStr);
    }

    @Override
    public void destroy() {

    }


    private String getRequestBody(HttpServletRequest req) {
        try {
            BufferedReader reader = req.getReader();
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            return sb.toString();
        } catch (IOException e) {
            log.info("请求体读取失败" + e.getMessage());
        }
        return "";
    }

    private void writeResponse(ServletResponse response, String responseString) throws IOException {
        response.setContentLength(-1);
        PrintWriter out = response.getWriter();
        out.print(responseString);
        out.flush();
        out.close();
    }

}