Filter for reading and logging HttpServletRequest body, and resetting the input stream

LoggerFilter

package com.paddypower.financials.market.management.rest.logging;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

import org.apache.commons.io.IOUtils;

public class LoggerFilter implements Filter {
	
	private Auditor auditor;

	public void destroy() {
		// Nothing to do
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		ResettableStreamHttpServletRequest wrappedRequest = new ResettableStreamHttpServletRequest(
				(HttpServletRequest) request);
		// wrappedRequest.getInputStream().read();
		String body = IOUtils.toString(wrappedRequest.getReader());
		auditor.audit(wrappedRequest.getRequestURI(),wrappedRequest.getUserPrincipal(), body);
		wrappedRequest.resetInputStream();
		chain.doFilter(wrappedRequest, response);

	}

	public void init(FilterConfig arg0) throws ServletException {
		// Nothing to do
	}

	private static class ResettableStreamHttpServletRequest extends
			HttpServletRequestWrapper {

		private byte[] rawData;
		private HttpServletRequest request;
		private ResettableServletInputStream servletStream;

		public ResettableStreamHttpServletRequest(HttpServletRequest request) {
			super(request);
			this.request = request;
			this.servletStream = new ResettableServletInputStream();
		}


		public void resetInputStream() {
			servletStream.stream = new ByteArrayInputStream(rawData);
		}

		@Override
		public ServletInputStream getInputStream() throws IOException {
			if (rawData == null) {
				rawData = IOUtils.toByteArray(this.request.getReader());
				servletStream.stream = new ByteArrayInputStream(rawData);
			}
			return servletStream;
		}

		@Override
		public BufferedReader getReader() throws IOException {
			if (rawData == null) {
				rawData = IOUtils.toByteArray(this.request.getReader());
				servletStream.stream = new ByteArrayInputStream(rawData);
			}
			return new BufferedReader(new InputStreamReader(servletStream));
		}
		

		private class ResettableServletInputStream extends ServletInputStream {

			private InputStream stream;

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

	public void setAuditor(Auditor auditor) {
		this.auditor = auditor;
	}
	
}

Thanks ! Really useful !!! 😄

I am calling Http POST to the REST endpoint, but making XML request, in my case 3rd party system can only make the SOAP request, now I need to remove soapenv:Envelope from the request and only pass the xml tags. I am using Spring Boot application.

Is there any way to read the request and update the POST data?

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:wer.com:dms:wsdls:organization">
   <soapenv:Header/>
   <soapenv:Body>
      <urn:getProfile>
         <getProfileRequest>
            <patientId>160166</patientId>
         </getProfileRequest>
      </urn:getProfile>
   </soapenv:Body>
</soapenv:Envelope>

Thank you.
It was really helpful.
Here is my working solution, that is up-to-date with packages' versions.

private static final class CopyableHttpServletRequestWrapper extends HttpServletRequestWrapper {

    private byte[] rawData;
    private HttpServletRequest request;
    private CopyableServletInputStream servletInputStream;

    private static final class CopyableServletInputStream extends ServletInputStream {

        private InputStream stream;

        public CopyableServletInputStream(InputStream stream) {
            this.stream = stream;
        }

        @Override
        public boolean isFinished() {
            try {
                int remainingBytes = stream.available();
                return 0 == remainingBytes;
            } catch (IOException ex) {
                return false;
            }
        }

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

        @Override
        public void setReadListener(ReadListener listener) { }

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

    private CopyableHttpServletRequestWrapper(HttpServletRequest request) {
        super(request);
        this.request = request;
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        copyBodyDataIfNecessary();
        return servletInputStream;
    }

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

    public void copyBodyDataIfNecessary() throws IOException {
        if(null == rawData) {
            rawData = IOUtils.toByteArray(request.getReader(), "utf-8");
            servletInputStream = new CopyableServletInputStream(new ByteArrayInputStream(rawData));
        }
    }

    public void resetStream() throws IOException {
        this.servletInputStream = new CopyableServletInputStream(new ByteArrayInputStream(rawData));
    }
}

very good!!!

Thank you every one, a little change because not working in my project by a cast wrong

private static final class CopyableHttpServletRequestWrapper extends HttpServletRequestWrapper {

        private byte[] rawData;
        private final HttpServletRequest request;
        private CopyableServletInputStream servletInputStream;

        private static final class CopyableServletInputStream extends ServletInputStream {

            private final InputStream stream;

            public CopyableServletInputStream(InputStream stream) {
                this.stream = stream;
            }

            @Override
            public boolean isFinished() {
                try {
                    int remainingBytes = stream.available();
                    return 0 == remainingBytes;
                } catch (IOException ex) {
                    return false;
                }
            }

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

            @Override
            public void setReadListener(ReadListener listener) {
            }

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

        private CopyableHttpServletRequestWrapper(HttpServletRequest request) {
            super(request);
            this.request = request;
        }

        @Override
        public ServletInputStream getInputStream() throws IOException {
            copyBodyDataIfNecessary();
            return servletInputStream;
        }

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

        public void copyBodyDataIfNecessary() throws IOException {
            if (null == rawData) {
                rawData = IOUtils.toByteArray(this.request.getInputStream());
                servletInputStream = new CopyableServletInputStream(new ByteArrayInputStream(rawData));
            }
        }

        public void resetStream() throws IOException {
            this.servletInputStream = new CopyableServletInputStream(new ByteArrayInputStream(rawData));
        }
    }