My implementation:
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.UUID;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ReadListener;
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletOutputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.WriteListener;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.io.output.TeeOutputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
public class ApiLoggingFilter implements Filter {
private static final Logger LOGGER = LoggerFactory.getLogger(ApiLoggingFilter.class);
ApiLoggingFilter(String requestIdParamName, String requestIdMDCParamName) {
this.requestIdParamName = requestIdParamName;
this.requestIdMDCParamName = requestIdMDCParamName;
}
private String requestIdParamName;
private String requestIdMDCParamName;
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
try {
HttpServletRequest httpServletRequest = (HttpServletRequest) request;
HttpServletResponse httpServletResponse = (HttpServletResponse) response;
Map<String, String> requestMap = this.getTypesafeRequestMap(httpServletRequest);
BufferedRequestWrapper bufferedRequest = new BufferedRequestWrapper(httpServletRequest);
BufferedResponseWrapper bufferedResponse = new BufferedResponseWrapper(httpServletResponse);
String requestId = requestMap.containsKey(requestIdParamName) ? requestMap.get(requestIdParamName)
: UUID.randomUUID().toString();
MDC.put(requestIdMDCParamName, requestId);
final StringBuilder logRequest = new StringBuilder("HTTP ").append(httpServletRequest.getMethod())
.append(" \"").append(httpServletRequest.getServletPath()).append("\" ").append(", parameters=")
.append(requestMap).append(", body=").append(bufferedRequest.getRequestBody())
.append(", remote_address=").append(httpServletRequest.getRemoteAddr());
LOGGER.info(logRequest.toString());
try {
chain.doFilter(bufferedRequest, bufferedResponse);
} finally {
final StringBuilder logResponse = new StringBuilder("HTTP RESPONSE ")
.append(bufferedResponse.getContent());
LOGGER.info(logResponse.toString());
MDC.clear();
}
} catch (Throwable a) {
LOGGER.error(a.getMessage());
}
}
private Map<String, String> getTypesafeRequestMap(HttpServletRequest request) {
Map<String, String> typesafeRequestMap = new HashMap<String, String>();
Enumeration<?> requestParamNames = request.getParameterNames();
while (requestParamNames.hasMoreElements()) {
String requestParamName = (String) requestParamNames.nextElement();
String requestParamValue;
if (requestParamName.equalsIgnoreCase("password")) {
requestParamValue = "********";
} else {
requestParamValue = request.getParameter(requestParamName);
}
typesafeRequestMap.put(requestParamName, requestParamValue);
}
return typesafeRequestMap;
}
@Override
public void destroy() {
}
private static final class BufferedRequestWrapper extends HttpServletRequestWrapper {
private ByteArrayInputStream bais = null;
private ByteArrayOutputStream baos = null;
private BufferedServletInputStream bsis = null;
private byte[] buffer = null;
public BufferedRequestWrapper(HttpServletRequest req) throws IOException {
super(req);
// Read InputStream and store its content in a buffer.
InputStream is = req.getInputStream();
this.baos = new ByteArrayOutputStream();
byte buf[] = new byte[1024];
int read;
while ((read = is.read(buf)) > 0) {
this.baos.write(buf, 0, read);
}
this.buffer = this.baos.toByteArray();
}
@Override
public ServletInputStream getInputStream() {
this.bais = new ByteArrayInputStream(this.buffer);
this.bsis = new BufferedServletInputStream(this.bais);
return this.bsis;
}
String getRequestBody() throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(this.getInputStream()));
String line = null;
StringBuilder inputBuffer = new StringBuilder();
do {
line = reader.readLine();
if (null != line) {
inputBuffer.append(line.trim());
}
} while (line != null);
reader.close();
return inputBuffer.toString().trim();
}
}
private static final class BufferedServletInputStream extends ServletInputStream {
private ByteArrayInputStream bais;
public BufferedServletInputStream(ByteArrayInputStream bais) {
this.bais = bais;
}
@Override
public int available() {
return this.bais.available();
}
@Override
public int read() {
return this.bais.read();
}
@Override
public int read(byte[] buf, int off, int len) {
return this.bais.read(buf, off, len);
}
@Override
public boolean isFinished() {
return false;
}
@Override
public boolean isReady() {
return true;
}
@Override
public void setReadListener(ReadListener readListener) {
}
}
public class TeeServletOutputStream extends ServletOutputStream {
private final TeeOutputStream targetStream;
public TeeServletOutputStream(OutputStream one, OutputStream two) {
targetStream = new TeeOutputStream(one, two);
}
@Override
public void write(int arg0) throws IOException {
this.targetStream.write(arg0);
}
public void flush() throws IOException {
super.flush();
this.targetStream.flush();
}
public void close() throws IOException {
super.close();
this.targetStream.close();
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setWriteListener(WriteListener writeListener) {
}
}
public class BufferedResponseWrapper implements HttpServletResponse {
HttpServletResponse original;
TeeServletOutputStream tee;
ByteArrayOutputStream bos;
public BufferedResponseWrapper(HttpServletResponse response) {
original = response;
}
public String getContent() {
return bos.toString();
}
public PrintWriter getWriter() throws IOException {
return original.getWriter();
}
public ServletOutputStream getOutputStream() throws IOException {
if (tee == null) {
bos = new ByteArrayOutputStream();
tee = new TeeServletOutputStream(original.getOutputStream(), bos);
}
return tee;
}
@Override
public String getCharacterEncoding() {
return original.getCharacterEncoding();
}
@Override
public String getContentType() {
return original.getContentType();
}
@Override
public void setCharacterEncoding(String charset) {
original.setCharacterEncoding(charset);
}
@Override
public void setContentLength(int len) {
original.setContentLength(len);
}
@Override
public void setContentLengthLong(long l) {
original.setContentLengthLong(l);
}
@Override
public void setContentType(String type) {
original.setContentType(type);
}
@Override
public void setBufferSize(int size) {
original.setBufferSize(size);
}
@Override
public int getBufferSize() {
return original.getBufferSize();
}
@Override
public void flushBuffer() throws IOException {
tee.flush();
}
@Override
public void resetBuffer() {
original.resetBuffer();
}
@Override
public boolean isCommitted() {
return original.isCommitted();
}
@Override
public void reset() {
original.reset();
}
@Override
public void setLocale(Locale loc) {
original.setLocale(loc);
}
@Override
public Locale getLocale() {
return original.getLocale();
}
@Override
public void addCookie(Cookie cookie) {
original.addCookie(cookie);
}
@Override
public boolean containsHeader(String name) {
return original.containsHeader(name);
}
@Override
public String encodeURL(String url) {
return original.encodeURL(url);
}
@Override
public String encodeRedirectURL(String url) {
return original.encodeRedirectURL(url);
}
@SuppressWarnings("deprecation")
@Override
public String encodeUrl(String url) {
return original.encodeUrl(url);
}
@SuppressWarnings("deprecation")
@Override
public String encodeRedirectUrl(String url) {
return original.encodeRedirectUrl(url);
}
@Override
public void sendError(int sc, String msg) throws IOException {
original.sendError(sc, msg);
}
@Override
public void sendError(int sc) throws IOException {
original.sendError(sc);
}
@Override
public void sendRedirect(String location) throws IOException {
original.sendRedirect(location);
}
@Override
public void setDateHeader(String name, long date) {
original.setDateHeader(name, date);
}
@Override
public void addDateHeader(String name, long date) {
original.addDateHeader(name, date);
}
@Override
public void setHeader(String name, String value) {
original.setHeader(name, value);
}
@Override
public void addHeader(String name, String value) {
original.addHeader(name, value);
}
@Override
public void setIntHeader(String name, int value) {
original.setIntHeader(name, value);
}
@Override
public void addIntHeader(String name, int value) {
original.addIntHeader(name, value);
}
@Override
public void setStatus(int sc) {
original.setStatus(sc);
}
@SuppressWarnings("deprecation")
@Override
public void setStatus(int sc, String sm) {
original.setStatus(sc, sm);
}
@Override
public String getHeader(String arg0) {
return original.getHeader(arg0);
}
@Override
public Collection<String> getHeaderNames() {
return original.getHeaderNames();
}
@Override
public Collection<String> getHeaders(String arg0) {
return original.getHeaders(arg0);
}
@Override
public int getStatus() {
return original.getStatus();
}
}
}
I've created a custom filter over my Spring app to log the request and responses including headers, params and body text.
It works fine for requests and responses usually, but when applied to a service which returns a large payload, the service returns all lines in full in the response but the service logs the response truncated to only a few lines. Response header "transfer-encoding": "chunked" is what I believe is causing the odd behaviour for the logging. I think my logging code might be defaulting to a fixed size in the absence of content-length as it is streaming.
Is there a wrapper class or better approach I could take to get to copy the stream until completion. I have scoured the web but haven't seen this specific question asked - this one came close https://stackoverflow.com/questions/59295514/how-to-stream-chunked-response-with-spring-boot-restcontroller
I tried numerous filter implementations others have posted but the behaviour remained the same.
