So this is basically Lathy's answer BUT updated for newer requirements for ServletInputStream.
Namely (for ServletInputStream), one has to implement:
public abstract boolean isFinished();
public abstract boolean isReady();
public abstract void setReadListener(ReadListener var1);
This is the edited Lathy's object
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
public class RequestWrapper extends HttpServletRequestWrapper {
private String _body;
public RequestWrapper(HttpServletRequest request) throws IOException {
super(request);
_body = "";
BufferedReader bufferedReader = request.getReader();
String line;
while ((line = bufferedReader.readLine()) != null){
_body += line;
}
}
@Override
public ServletInputStream getInputStream() throws IOException {
CustomServletInputStream kid = new CustomServletInputStream(_body.getBytes());
return kid;
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(this.getInputStream()));
}
}
and somewhere (??) I found this (which is a first-class class that deals with the "extra" methods.
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
public class CustomServletInputStream extends ServletInputStream {
private byte[] myBytes;
private int lastIndexRetrieved = -1;
private ReadListener readListener = null;
public CustomServletInputStream(String s) {
try {
this.myBytes = s.getBytes("UTF-8");
} catch (UnsupportedEncodingException ex) {
throw new IllegalStateException("JVM did not support UTF-8", ex);
}
}
public CustomServletInputStream(byte[] inputBytes) {
this.myBytes = inputBytes;
}
@Override
public boolean isFinished() {
return (lastIndexRetrieved == myBytes.length - 1);
}
@Override
public boolean isReady() {
// This implementation will never block
// We also never need to call the readListener from this method, as this method will never return false
return isFinished();
}
@Override
public void setReadListener(ReadListener readListener) {
this.readListener = readListener;
if (!isFinished()) {
try {
readListener.onDataAvailable();
} catch (IOException e) {
readListener.onError(e);
}
} else {
try {
readListener.onAllDataRead();
} catch (IOException e) {
readListener.onError(e);
}
}
}
@Override
public int read() throws IOException {
int i;
if (!isFinished()) {
i = myBytes[lastIndexRetrieved + 1];
lastIndexRetrieved++;
if (isFinished() && (readListener != null)) {
try {
readListener.onAllDataRead();
} catch (IOException ex) {
readListener.onError(ex);
throw ex;
}
}
return i;
} else {
return -1;
}
}
};
Ultimately, I was just trying to log the requests. And the above frankensteined together pieces helped me create the below.
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.Principal;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.io.IOUtils;
//one or the other based on spring version
//import org.springframework.boot.autoconfigure.web.ErrorAttributes;
import org.springframework.boot.web.servlet.error.ErrorAttributes;
import org.springframework.core.Ordered;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.filter.OncePerRequestFilter;
/**
* A filter which logs web requests that lead to an error in the system.
*/
@Component
public class LogRequestFilter extends OncePerRequestFilter implements Ordered {
// I tried apache.commons and slf4g loggers. (one or the other in these next 2 lines of declaration */
//private final static org.apache.commons.logging.Log logger = org.apache.commons.logging.LogFactory.getLog(LogRequestFilter.class);
private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(LogRequestFilter.class);
// put filter at the end of all other filters to make sure we are processing after all others
private int order = Ordered.LOWEST_PRECEDENCE - 8;
private ErrorAttributes errorAttributes;
@Override
public int getOrder() {
return order;
}
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
String temp = ""; /* for a breakpoint, remove for production/real code */
/* change to true for easy way to comment out this code, remove this if-check for production/real code */
if (false) {
filterChain.doFilter(request, response);
return;
}
/* make a "copy" to avoid issues with body-can-only-read-once issues */
RequestWrapper reqWrapper = new RequestWrapper(request);
int status = HttpStatus.INTERNAL_SERVER_ERROR.value();
// pass through filter chain to do the actual request handling
filterChain.doFilter(reqWrapper, response);
status = response.getStatus();
try {
Map<String, Object> traceMap = getTrace(reqWrapper, status);
// body can only be read after the actual request handling was done!
this.getBodyFromTheRequestCopy(reqWrapper, traceMap);
/* now do something with all the pieces of information gatherered */
this.logTrace(reqWrapper, traceMap);
} catch (Exception ex) {
logger.error("LogRequestFilter FAILED: " + ex.getMessage(), ex);
}
}
private void getBodyFromTheRequestCopy(RequestWrapper rw, Map<String, Object> trace) {
try {
if (rw != null) {
byte[] buf = IOUtils.toByteArray(rw.getInputStream());
//byte[] buf = rw.getInputStream();
if (buf.length > 0) {
String payloadSlimmed;
try {
String payload = new String(buf, 0, buf.length, rw.getCharacterEncoding());
payloadSlimmed = payload.trim().replaceAll(" +", " ");
} catch (UnsupportedEncodingException ex) {
payloadSlimmed = "[unknown]";
}
trace.put("body", payloadSlimmed);
}
}
} catch (IOException ioex) {
trace.put("body", "EXCEPTION: " + ioex.getMessage());
}
}
private void logTrace(HttpServletRequest request, Map<String, Object> trace) {
Object method = trace.get("method");
Object path = trace.get("path");
Object statusCode = trace.get("statusCode");
logger.info(String.format("%s %s produced an status code '%s'. Trace: '%s'", method, path, statusCode,
trace));
}
protected Map<String, Object> getTrace(HttpServletRequest request, int status) {
Throwable exception = (Throwable) request.getAttribute("javax.servlet.error.exception");
Principal principal = request.getUserPrincipal();
Map<String, Object> trace = new LinkedHashMap<String, Object>();
trace.put("method", request.getMethod());
trace.put("path", request.getRequestURI());
if (null != principal) {
trace.put("principal", principal.getName());
}
trace.put("query", request.getQueryString());
trace.put("statusCode", status);
Enumeration headerNames = request.getHeaderNames();
while (headerNames.hasMoreElements()) {
String key = (String) headerNames.nextElement();
String value = request.getHeader(key);
trace.put("header:" + key, value);
}
if (exception != null && this.errorAttributes != null) {
trace.put("error", this.errorAttributes
.getErrorAttributes((WebRequest) new ServletRequestAttributes(request), true));
}
return trace;
}
}
Please take this code with a grain of salt.
The MOST important "test" is if a POST works with a payload. This is what will expose "double read" issues.
pseudo example code
import org.springframework.web.bind.annotation.*;
@RestController
@RequestMapping("myroute")
public class MyController {
@RequestMapping(method = RequestMethod.POST, produces = "application/json")
@ResponseBody
public String getSomethingExample(@RequestBody MyCustomObject input) {
String returnValue = "";
return returnValue;
}
}
You can replace "MyCustomObject" with plain ole "Object" if you just want to test.
This answer is frankensteined from several different SOF posts and examples..but it took a while to pull it all together so I hope it helps a future reader.
Please upvote Lathy's answer before mine. I could have not gotten this far without it.
Below is one/some of the exceptions I got while working this out.
getReader() has already been called for this request
Looks like some of the places I "borrowed" from are here:
http://slackspace.de/articles/log-request-body-with-spring-boot/
https://github.com/c0nscience/spring-web-logging/blob/master/src/main/java/org/zalando/springframework/web/logging/LoggingFilter.java
https://howtodoinjava.com/servlets/httpservletrequestwrapper-example-read-request-body/
https://www.oodlestechnologies.com/blogs/How-to-create-duplicate-object-of-httpServletRequest-object
https://github.com/c0nscience/spring-web-logging/blob/master/src/main/java/org/zalando/springframework/web/logging/LoggingFilter.java
January 2021 APPEND.
I have learned the hard way that the above code does NOT work for
x-www-form-urlencoded
Consider the example below:
@CrossOrigin
@ResponseBody
@PostMapping(path = "/mypath", consumes = {MediaType.APPLICATION_FORM_URLENCODED_VALUE})
public ResponseEntity myMethodName(@RequestParam Map<String, String> parameters
) {
/* DO YOU GET ANY PARAMETERS HERE? Or are they empty because of logging/auditing filter ?*/
return new ResponseEntity(HttpStatus.OK);
}
I had to go through several of the other examples here.
I came up with a "wrapper" that works explicitly for APPLICATION_FORM_URLENCODED_VALUE
import org.apache.commons.io.IOUtils;
import org.springframework.http.MediaType;
import org.springframework.web.util.ContentCachingRequestWrapper;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
/**
* Makes a "copy" of the HttpRequest so the body can be accessed more than 1 time.
* WORKS WITH APPLICATION_FORM_URLENCODED_VALUE
* See : https://mcmap.net/q/88787/-why-do-we-wrap-httpservletrequest-the-api-provides-an-httpservletrequestwrapper-but-what-do-we-gain-from-wrapping-the-request/44187955#44187955
*/
public final class AppFormUrlEncodedSpecificContentCachingRequestWrapper extends ContentCachingRequestWrapper {
public static final String ERROR_MSG_CONTENT_TYPE_NOT_SUPPORTED = "ContentType not supported. (Input ContentType(s)=\"%1$s\", Supported ContentType(s)=\"%2$s\")";
public static final String ERROR_MSG_PERSISTED_CONTENT_CACHING_REQUEST_WRAPPER_CONSTRUCTOR_FAILED = "AppFormUrlEncodedSpecificContentCachingRequestWrapper constructor failed";
private static final org.slf4j.Logger LOGGER = org.slf4j.LoggerFactory.getLogger(AppFormUrlEncodedSpecificContentCachingRequestWrapper.class);
private byte[] body;
private ServletInputStream inputStream;
public AppFormUrlEncodedSpecificContentCachingRequestWrapper(HttpServletRequest request) {
super(request);
super.getParameterMap(); // init cache in ContentCachingRequestWrapper. THIS IS THE VITAL CALL so that "@RequestParam Map<String, String> parameters" are populated on the REST Controller. See https://mcmap.net/q/88067/-http-servlet-request-lose-params-from-post-body-after-read-it-once/64924380#64924380
String contentType = request.getContentType();
/* EXPLICTLY check for APPLICATION_FORM_URLENCODED_VALUE and allow nothing else */
if (null == contentType || !contentType.equalsIgnoreCase(MediaType.APPLICATION_FORM_URLENCODED_VALUE)) {
IllegalArgumentException ioex = new IllegalArgumentException(String.format(ERROR_MSG_CONTENT_TYPE_NOT_SUPPORTED, contentType, MediaType.APPLICATION_FORM_URLENCODED_VALUE));
LOGGER.error(ERROR_MSG_PERSISTED_CONTENT_CACHING_REQUEST_WRAPPER_CONSTRUCTOR_FAILED, ioex);
throw ioex;
}
try {
loadBody(request);
} catch (IOException ioex) {
throw new RuntimeException(ioex);
}
}
private void loadBody(HttpServletRequest request) throws IOException {
body = IOUtils.toByteArray(request.getInputStream());
inputStream = new CustomServletInputStream(this.getBody());
}
private byte[] getBody() {
return body;
}
@Override
public ServletInputStream getInputStream() throws IOException {
if (inputStream != null) {
return inputStream;
}
return super.getInputStream();
}
}
Note Andrew Sneck's answer on this same page.
It is pretty much this : https://programmersought.com/article/23981013626/
I have not had time to harmonize the two above implementations (my two that is).
So I created a Factory to "choose" from the two:
import org.springframework.http.MediaType;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.IOException;
/**
* Factory to return different concretes of HttpServletRequestWrapper. APPLICATION_FORM_URLENCODED_VALUE needs a different concrete.
*/
public class HttpServletRequestWrapperFactory {
public static final String ERROR_MSG_HTTP_SERVLET_REQUEST_WRAPPER_FACTORY_CREATE_HTTP_SERVLET_REQUEST_WRAPPER_FAILED = "HttpServletRequestWrapperFactory createHttpServletRequestWrapper FAILED";
public static HttpServletRequestWrapper createHttpServletRequestWrapper(final HttpServletRequest request) {
HttpServletRequestWrapper returnItem = null;
if (null != request) {
String contentType = request.getContentType();
if (null != contentType && contentType.equalsIgnoreCase(MediaType.APPLICATION_FORM_URLENCODED_VALUE)) {
returnItem = new AppFormUrlEncodedSpecificContentCachingRequestWrapper(request);
} else {
try {
returnItem = new PersistedBodyRequestWrapper(request);
} catch (IOException ioex) {
throw new RuntimeException(ERROR_MSG_HTTP_SERVLET_REQUEST_WRAPPER_FACTORY_CREATE_HTTP_SERVLET_REQUEST_WRAPPER_FAILED, ioex);
}
}
}
return returnItem;
}
}
Below is the "other" one that works with JSON, etc. It is the other concrete that the Factory can output. I put it here so that my Jan 2021 APPEND is consistent..I don't know if the code below is perfect consistent with my original answer:
import org.springframework.http.MediaType;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.Map;
/**
* Makes a "copy" of the HttpRequest so the body can be accessed more than 1 time.
* See : https://mcmap.net/q/88787/-why-do-we-wrap-httpservletrequest-the-api-provides-an-httpservletrequestwrapper-but-what-do-we-gain-from-wrapping-the-request/44187955#44187955
* DOES NOT WORK WITH APPLICATION_FORM_URLENCODED_VALUE
*/
public final class PersistedBodyRequestWrapper extends HttpServletRequestWrapper {
public static final String ERROR_MSG_CONTENT_TYPE_NOT_SUPPORTED = "ContentType not supported. (ContentType=\"%1$s\")";
public static final String ERROR_MSG_PERSISTED_BODY_REQUEST_WRAPPER_CONSTRUCTOR_FAILED = "PersistedBodyRequestWrapper constructor FAILED";
private static final org.slf4j.Logger LOGGER = org.slf4j.LoggerFactory.getLogger(PersistedBodyRequestWrapper.class);
private String persistedBody;
private final Map<String, String[]> parameterMap;
public PersistedBodyRequestWrapper(final HttpServletRequest request) throws IOException {
super(request);
String contentType = request.getContentType();
/* Allow everything EXCEPT APPLICATION_FORM_URLENCODED_VALUE */
if (null != contentType && contentType.equalsIgnoreCase(MediaType.APPLICATION_FORM_URLENCODED_VALUE)) {
IllegalArgumentException ioex = new IllegalArgumentException(String.format(ERROR_MSG_CONTENT_TYPE_NOT_SUPPORTED, MediaType.APPLICATION_FORM_URLENCODED_VALUE));
LOGGER.error(ERROR_MSG_PERSISTED_BODY_REQUEST_WRAPPER_CONSTRUCTOR_FAILED, ioex);
throw ioex;
}
parameterMap = request.getParameterMap();
this.persistedBody = "";
BufferedReader bufferedReader = request.getReader();
String line;
while ((line = bufferedReader.readLine()) != null) {
this.persistedBody += line;
}
}
@Override
public ServletInputStream getInputStream() throws IOException {
CustomServletInputStream csis = new CustomServletInputStream(this.persistedBody.getBytes(StandardCharsets.UTF_8));
return csis;
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(this.getInputStream()));
}
@Override
public Map<String, String[]> getParameterMap() {
return this.parameterMap;
}
}
