Http Servlet request lose params from POST body after read it once

Question

I m trying to accessing two http request parameters in a Java Servlet filter  nothing new here  but was surprised to find that the parameters have already been consumed  Because of this  it is not available anymore in the filter chain   It seems that this only occurs when the parameters comes in a POST request body  a form submit  for example    Is there a way to read the parameters and NOT consume them   So far I ve found only this reference  Servlet Filter using request getParameter loses Form data   Thanks

User · Answer

First of all we should not read parameters within the filter. Usually the headers are read in the filter to do few authentication tasks. Having said that one can read the HttpRequest body completely in the Filter or Interceptor by using the CharStreams:

String body = com.google.common.io.CharStreams.toString(request.getReader());

This does not affect the subsequent reads at all.

User · Answer

I know I m late  but this question was still relevant for me and this SO post was one of the top hits in Google  I m going ahead and post my solution in the hopes that someone else might save couple of hours   In my case I needed to log all requests and responses with their bodies  Using Spring Framework the answer is actually quite simple  just use ContentCachingRequestWrapper and ContentCachingResponseWrapper   import org springframework web util ContentCachingRequestWrapper  import org springframework web util ContentCachingResponseWrapper   import javax servlet    import javax servlet http HttpServletRequest  import javax servlet http HttpServletResponse  import java io IOException   public class LoggingFilter implements Filter         Override     public void init FilterConfig filterConfig  throws ServletException                Override     public void destroy                  Override     public void doFilter ServletRequest request  ServletResponse response  FilterChain chain              throws IOException  ServletException            ContentCachingRequestWrapper requestWrapper   new ContentCachingRequestWrapper  HttpServletRequest  request           ContentCachingResponseWrapper responseWrapper   new ContentCachingResponseWrapper  HttpServletResponse  response            try               chain doFilter requestWrapper  responseWrapper             finally                String requestBody   new String requestWrapper getContentAsByteArray                 String responseBody   new String responseWrapper getContentAsByteArray                    Do not forget this line after reading response content or actual response will be empty              responseWrapper copyBodyToResponse                    Write request and response body  headers  timestamps etc  to log files

User · Answer

Just overwriting of getInputStream   did not work in my case  My server implementation seems to parse parameters without calling  this method  I did not find any other way  but re-implement the all four getParameter  methods as well  Here is the code of getParameterMap  Apache Http Client and Google Guava library used     Override public Map lt String  String   gt  getParameterMap         Iterable lt NameValuePair gt  params   URLEncodedUtils parse getQueryString    NullUtils UTF8        try           String cts   getContentType            if  cts    null                ContentType ct   ContentType parse cts               if  ct getMimeType   equals ContentType APPLICATION FORM URLENCODED getMimeType                       List lt NameValuePair gt  postParams   URLEncodedUtils parse IOUtils toString getReader     NullUtils UTF8                   params   Iterables concat params  postParams                                 catch  IOException e            throw new IllegalStateException e             Map lt String  String   gt  result   toMap params       return result     public static Map lt String  String   gt  toMap Iterable lt NameValuePair gt  body        Map lt String  String   gt  result   new LinkedHashMap lt  gt         for  NameValuePair e   body            String key   e getName            String value   e getValue            if  result containsKey key                 String   newValue   ObjectArrays concat result get key   value               result remove key               result put key  newValue             else               result put key  new String    value                        return result

User · Answer

If you have control over the request  you could set the content type to binary octet-stream  This allows to query for parameters without consuming the input stream   However  this might be specific to some application servers  I only tested tomcat  jetty seems to behave the same way according to https   stackoverflow com a 11434646 957103

User · Answer

The above answers were very helpful  but still had some problems in my experience  On tomcat 7 servlet 3 0  the getParamter and getParamterValues also had to be overwritten  The solution here includes both get-query parameters and the post-body  It allows for getting raw-string easily    Like the other solutions it uses Apache commons-io and Googles Guava   In this solution the getParameter  methods do not throw IOException but they use super getInputStream    to get the body  which may throw IOException  I catch it and throw runtimeException  It is not so nice   import com google common collect Iterables  import com google common collect ObjectArrays   import org apache commons io IOUtils  import org apache http NameValuePair  import org apache http client utils URLEncodedUtils  import org apache http entity ContentType   import java io BufferedReader  import java io ByteArrayInputStream  import java io ByteArrayOutputStream  import java io IOException  import java io InputStreamReader  import java io UnsupportedEncodingException  import java nio charset Charset  import java util Collections  import java util LinkedHashMap  import java util List  import java util Map   import javax servlet ServletInputStream  import javax servlet http HttpServletRequest  import javax servlet http HttpServletRequestWrapper          Purpose of this class is to make getParameter   return post data AND also be able to get entire    body-string  In native implementation any of those two works  but not both together      public class MultiReadHttpServletRequest extends HttpServletRequestWrapper       public static final String UTF8    UTF-8       public static final Charset UTF8 CHARSET   Charset forName UTF8       private ByteArrayOutputStream cachedBytes      private Map lt String  String   gt  parameterMap       public MultiReadHttpServletRequest HttpServletRequest request            super request              public static void toMap Iterable lt NameValuePair gt  inputParams  Map lt String  String   gt  toMap            for  NameValuePair e   inputParams                String key   e getName                String value   e getValue                if  toMap containsKey key                     String   newValue   ObjectArrays concat toMap get key   value                   toMap remove key                   toMap put key  newValue                 else                   toMap put key  new String   value                                        Override     public ServletInputStream getInputStream   throws IOException           if  cachedBytes    null  cacheInputStream            return new CachedServletInputStream                Override     public BufferedReader getReader   throws IOException           return new BufferedReader new InputStreamReader getInputStream                 private void cacheInputStream   throws IOException          Cache the inputStream in order to read it multiple times  For        convenience  I use apache commons IOUtils                 cachedBytes   new ByteArrayOutputStream            IOUtils copy super getInputStream    cachedBytes               Override     public String getParameter String key            Map lt String  String   gt  parameterMap   getParameterMap            String   values   parameterMap get key           return values    null  amp  amp  values length  gt  0   values 0    null              Override     public String   getParameterValues String key            Map lt String  String   gt  parameterMap   getParameterMap            return parameterMap get key               Override     public Map lt String  String   gt  getParameterMap             if  parameterMap    null                Map lt String  String   gt  result   new LinkedHashMap lt String  String   gt                 decode getQueryString    result               decode getPostBodyAsString    result               parameterMap   Collections unmodifiableMap result                     return parameterMap             private void decode String queryString  Map lt String  String   gt  result            if  queryString    null  toMap decodeParams queryString   result              private Iterable lt NameValuePair gt  decodeParams String body            Iterable lt NameValuePair gt  params   URLEncodedUtils parse body  UTF8 CHARSET           try               String cts   getContentType                if  cts    null                    ContentType ct   ContentType parse cts                   if  ct getMimeType   equals ContentType APPLICATION FORM URLENCODED getMimeType                           List lt NameValuePair gt  postParams   URLEncodedUtils parse IOUtils toString getReader     UTF8 CHARSET                       params   Iterables concat params  postParams                                             catch  IOException e                throw new IllegalStateException e                     return params             public String getPostBodyAsString             try               if  cachedBytes    null  cacheInputStream                return cachedBytes toString UTF8             catch  UnsupportedEncodingException e                throw new RuntimeException e             catch  IOException e                throw new RuntimeException e                           An inputStream which reads the cached request body        public class CachedServletInputStream extends ServletInputStream           private ByteArrayInputStream input           public CachedServletInputStream                    create a new input stream from the cached request body                input   new ByteArrayInputStream cachedBytes toByteArray                         Override         public int read   throws IOException               return input read                          Override     public String toString             String query   dk bnr util StringUtil nullToEmpty getQueryString             StringBuilder sb   new StringBuilder            sb append  URL     append getRequestURI    append query isEmpty                query  append     body              sb append getPostBodyAsString             sb append               return sb toString

User · Answer

you can use servlet filter chain  but instead use the original one  you can create your own request yourownrequests extends HttpServletRequestWrapper

User · Answer

Spring has built-in support for this with an AbstractRequestLoggingFilter    Bean public Filter loggingFilter        final AbstractRequestLoggingFilter filter   new AbstractRequestLoggingFilter              Override         protected void beforeRequest final HttpServletRequest request  final String message                         Override         protected void afterRequest final HttpServletRequest request  final String message                           filter setIncludePayload true       filter setIncludeQueryString false       filter setMaxPayloadLength 1000000        return filter      Unfortunately you still won t be able to read the payload directly off the request  but the String message parameter will include the payload so you can grab  it from there as follows   String body   message substring message indexOf       message lastIndexOf

User · Answer

As an aside  an alternative way to solve this problem is to not use the filter chain and instead build your own interceptor component  perhaps using aspects  which can operate on the parsed request body  It will also likely be more efficient as you are only converting the request InputStream into your own model object once   However  I still think it s reasonable to want to read the request body more than once particularly as the request moves through the filter chain  I would typically use filter chains for certain operations that I want to keep at the HTTP layer  decoupled from the service components   As suggested by Will Hartung I achieved this by extending HttpServletRequestWrapper  consuming the request InputStream and essentially caching the bytes   public class MultiReadHttpServletRequest extends HttpServletRequestWrapper     private ByteArrayOutputStream cachedBytes     public MultiReadHttpServletRequest HttpServletRequest request        super request           Override   public ServletInputStream getInputStream   throws IOException       if  cachedBytes    null        cacheInputStream           return new CachedServletInputStream            Override   public BufferedReader getReader   throws IOException      return new BufferedReader new InputStreamReader getInputStream             private void cacheInputStream   throws IOException          Cache the inputstream in order to read it multiple times  For        convenience  I use apache commons IOUtils             cachedBytes   new ByteArrayOutputStream        IOUtils copy super getInputStream    cachedBytes             An inputstream which reads the cached request body      public class CachedServletInputStream extends ServletInputStream       private ByteArrayInputStream input       public CachedServletInputStream              create a new input stream from the cached request body          input   new ByteArrayInputStream cachedBytes toByteArray                 Override     public int read   throws IOException         return input read                  Now the request body can be read more than once by wrapping the original request before passing it through the filter chain   public class MyFilter implements Filter      Override   public void doFilter ServletRequest request  ServletResponse response          FilterChain chain  throws IOException  ServletException           wrap the request in order to read the inputstream multiple times        MultiReadHttpServletRequest multiReadRequest   new MultiReadHttpServletRequest  HttpServletRequest  request           here I read the inputstream and do my thing with it  when I pass the        wrapped request through the filter chain  the rest of the filters  and        request handlers may read the cached inputstream             doMyThing multiReadRequest getInputStream           OR     anotherUsage multiReadRequest getReader         chain doFilter multiReadRequest  response           This solution will also allow you to read the request body multiple times via the getParameterXXX methods because the underlying call is getInputStream    which will of course read the cached request InputStream   Edit  For newer version of ServletInputStream interface  You need to provide implementation of few more methods like isReady  setReadListener etc  Refer this question as provided in comment below

User · Answer

I too had the same issue and I believe the code below is more simple and it is working for me   public class MultiReadHttpServletRequest extends  HttpServletRequestWrapper     private String  body   public MultiReadHttpServletRequest 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      final ByteArrayInputStream byteArrayInputStream   new ByteArrayInputStream  body getBytes        return new ServletInputStream            public int read   throws IOException              return byteArrayInputStream read                       Override public BufferedReader getReader   throws IOException      return new BufferedReader new InputStreamReader this getInputStream            in the filter java class   HttpServletRequest properRequest     HttpServletRequest  req   MultiReadHttpServletRequest wrappedRequest   new MultiReadHttpServletRequest properRequest   req   wrappedRequest  inputJson   IOUtils toString req getReader     System out println  body  inputJson     Please let me know if you have any queries

User · Answer

The method getContentAsByteArray   of the Spring class ContentCachingRequestWrapper  reads the body multiple times  but the methods getInputStream   and getReader   of the same class do not read the body multiple times    This class caches the request body by consuming the InputStream  If we read the InputStream in one of the filters  then other subsequent filters in the filter chain can t read it anymore  Because of this limitation  this class is not suitable in all situations     In my case more general solution that solved this problem was to add following three classes to my Spring boot project  and the required dependencies to the pom file    CachedBodyHttpServletRequest java   public class CachedBodyHttpServletRequest extends HttpServletRequestWrapper        private byte   cachedBody       public CachedBodyHttpServletRequest HttpServletRequest request  throws IOException           super request           InputStream requestInputStream   request getInputStream            this cachedBody   StreamUtils copyToByteArray requestInputStream               Override     public ServletInputStream getInputStream   throws IOException           return new CachedBodyServletInputStream this cachedBody               Override     public BufferedReader getReader   throws IOException              Create a reader from cachedContent            and return it         ByteArrayInputStream byteArrayInputStream   new ByteArrayInputStream this cachedBody           return new BufferedReader new InputStreamReader byteArrayInputStream              CachedBodyServletInputStream java   public class CachedBodyServletInputStream extends ServletInputStream        private InputStream cachedBodyInputStream       public CachedBodyServletInputStream byte   cachedBody            this cachedBodyInputStream   new ByteArrayInputStream cachedBody               Override     public boolean isFinished             try               return cachedBodyInputStream available      0            catch  IOException e                   TODO Auto-generated catch block             e printStackTrace                      return false              Override     public boolean isReady             return true              Override     public void setReadListener ReadListener readListener            throw new UnsupportedOperationException                Override     public int read   throws IOException           return cachedBodyInputStream read              ContentCachingFilter java    Order value   Ordered HIGHEST PRECEDENCE   Component  WebFilter filterName    ContentCachingFilter   urlPatterns         public class ContentCachingFilter extends OncePerRequestFilter         Override     protected void doFilterInternal HttpServletRequest httpServletRequest  HttpServletResponse httpServletResponse  FilterChain filterChain  throws ServletException  IOException           System out println  IN  ContentCachingFilter             CachedBodyHttpServletRequest cachedBodyHttpServletRequest   new CachedBodyHttpServletRequest httpServletRequest           filterChain doFilter cachedBodyHttpServletRequest  httpServletResponse             I also added the following dependencies to pom    lt dependency gt       lt groupId gt org springframework lt  groupId gt       lt artifactId gt spring-webmvc lt  artifactId gt       lt version gt 5 2 0 RELEASE lt  version gt   lt  dependency gt   lt dependency gt       lt groupId gt javax servlet lt  groupId gt       lt artifactId gt javax servlet-api lt  artifactId gt       lt version gt 4 0 1 lt  version gt   lt  dependency gt   lt dependency gt       lt groupId gt com fasterxml jackson core lt  groupId gt       lt artifactId gt jackson-databind lt  artifactId gt       lt version gt 2 10 0 lt  version gt   lt  dependency gt    A tuturial and full source code is located here  https   www baeldung com spring-reading-httpservletrequest-multiple-times

User · Answer

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    quot  quot           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  quot extra quot  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  quot UTF-8 quot              catch  UnsupportedEncodingException ex                throw new IllegalStateException  quot JVM did not support UTF-8 quot   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    amp  amp   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    quot  quot      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  quot copy quot  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 lt String  Object gt  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  quot LogRequestFilter FAILED   quot    ex getMessage    ex                        private void getBodyFromTheRequestCopy RequestWrapper rw  Map lt String  Object gt  trace            try               if  rw    null                    byte   buf   IOUtils toByteArray rw getInputStream                       byte   buf   rw getInputStream                    if  buf length  gt  0                        String payloadSlimmed                      try                           String payload   new String buf  0  buf length  rw getCharacterEncoding                             payloadSlimmed   payload trim   replaceAll  quot    quot    quot   quot                          catch  UnsupportedEncodingException ex                            payloadSlimmed    quot  unknown  quot                                              trace put  quot body quot   payloadSlimmed                                             catch  IOException ioex                trace put  quot body quot    quot EXCEPTION   quot    ioex getMessage                          private void logTrace HttpServletRequest request  Map lt String  Object gt  trace            Object method   trace get  quot method quot            Object path   trace get  quot path quot            Object statusCode   trace get  quot statusCode quot             logger info String format  quot  s  s produced an status code   s   Trace    s  quot   method  path  statusCode                  trace               protected Map lt String  Object gt  getTrace HttpServletRequest request  int status            Throwable exception    Throwable  request getAttribute  quot javax servlet error exception quot             Principal principal   request getUserPrincipal             Map lt String  Object gt  trace   new LinkedHashMap lt String  Object gt             trace put  quot method quot   request getMethod             trace put  quot path quot   request getRequestURI             if  null    principal                trace put  quot principal quot   principal getName                       trace put  quot query quot   request getQueryString             trace put  quot statusCode quot   status            Enumeration headerNames   request getHeaderNames            while  headerNames hasMoreElements                  String key    String  headerNames nextElement                String value   request getHeader key               trace put  quot header  quot    key  value                      if  exception    null  amp  amp  this errorAttributes    null                trace put  quot error quot   this errorAttributes                      getErrorAttributes  WebRequest  new ServletRequestAttributes request   true                       return trace           Please take this code with a grain of salt  The MOST important  quot test quot  is if a POST works with a payload   This is what will expose  quot double read quot  issues  pseudo example code import org springframework web bind annotation      RestController  RequestMapping  quot myroute quot   public class MyController        RequestMapping method   RequestMethod POST  produces    quot application json quot        ResponseBody     public String getSomethingExample  RequestBody MyCustomObject input             String returnValue    quot  quot            return returnValue           You can replace  quot MyCustomObject quot  with plain ole  quot Object quot  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  quot borrowed quot  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    quot  mypath quot   consumes    MediaType APPLICATION FORM URLENCODED VALUE       public ResponseEntity myMethodName  RequestParam Map lt String  String gt  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  quot wrapper quot  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  quot copy quot  of the HttpRequest so the body can be accessed more than 1 time     WORKS WITH APPLICATION FORM URLENCODED VALUE    See   https   stackoverflow com questions 44182370 why-do-we-wrap-httpservletrequest-the-api-provides-an-httpservletrequestwrappe 44187955 44187955     public final class AppFormUrlEncodedSpecificContentCachingRequestWrapper extends ContentCachingRequestWrapper        public static final String ERROR MSG CONTENT TYPE NOT SUPPORTED    quot ContentType not supported   Input ContentType s    quot  1 s  quot   Supported ContentType s    quot  2 s  quot   quot        public static final String ERROR MSG PERSISTED CONTENT CACHING REQUEST WRAPPER CONSTRUCTOR FAILED    quot AppFormUrlEncodedSpecificContentCachingRequestWrapper constructor failed quot        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  quot  RequestParam Map lt String  String gt  parameters quot  are populated on the REST Controller   See https   stackoverflow com questions 10210645 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  quot choose quot  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    quot HttpServletRequestWrapperFactory createHttpServletRequestWrapper FAILED quot        public static HttpServletRequestWrapper createHttpServletRequestWrapper final HttpServletRequest request            HttpServletRequestWrapper returnItem   null           if  null    request                String contentType   request getContentType                if  null    contentType  amp  amp  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  quot other quot  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  quot copy quot  of the HttpRequest so the body can be accessed more than 1 time     See   https   stackoverflow com questions 44182370 why-do-we-wrap-httpservletrequest-the-api-provides-an-httpservletrequestwrappe 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    quot ContentType not supported   ContentType   quot  1 s  quot   quot        public static final String ERROR MSG PERSISTED BODY REQUEST WRAPPER CONSTRUCTOR FAILED    quot PersistedBodyRequestWrapper constructor FAILED quot        private static final org slf4j Logger LOGGER   org slf4j LoggerFactory getLogger PersistedBodyRequestWrapper class        private String persistedBody       private final Map lt String  String   gt  parameterMap       public PersistedBodyRequestWrapper final HttpServletRequest request  throws IOException           super request            String contentType   request getContentType               Allow everything EXCEPT APPLICATION FORM URLENCODED VALUE            if  null    contentType  amp  amp  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    quot  quot           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 lt String  String   gt  getParameterMap             return this parameterMap

User · Answer

The only way would be for you to consume the entire input stream yourself in the filter  take what you want from it  and then create a new InputStream for the content you read  and put that InputStream in to a ServletRequestWrapper  or HttpServletRequestWrapper     The downside is you ll have to parse the payload yourself  the standard doesn t make that capability available to you   Addenda --  As I said  you need to look at HttpServletRequestWrapper   In a filter  you continue along by calling FilterChain doFilter request  response    For trivial filters  the request and response are the same as the ones passed in to the filter  That doesn t have to be the case  You can replace those with your own requests and or responses   HttpServletRequestWrapper is specifically designed to facilitate this  You pass it the original request  and then you can intercept all of the calls  You create your own subclass of this  and replace the getInputStream method with one of your own  You can t change the input stream of the original request  so instead you have this wrapper and return your own input stream   The simplest case is to consume the original requests input stream in to a byte buffer  do whatever magic you want on it  then create a new ByteArrayInputStream from that buffer  This is what is returned in your wrapper  which is passed to the FilterChain doFilter method   You ll need to subclass ServletInputStream and make another wrapper for your ByteArrayInputStream  but that s not a big deal either

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I found good solution for any format of request body  I tested for application x-www-form-urlencoded and application json both worked very well  Problem of ContentCachingRequestWrapper that is designed only for x-www-form-urlencoded request body  but not work with e g  json  I found solution for json link  It had trouble that it didn t support x-www-form-urlencoded  I joined both in my code  import org apache commons io IOUtils  import org springframework web util ContentCachingRequestWrapper   import javax servlet ReadListener  import javax servlet ServletInputStream  import javax servlet http HttpServletRequest  import java io BufferedReader  import java io ByteArrayInputStream  import java io IOException  import java io InputStreamReader   public class MyContentCachingRequestWrapper extends ContentCachingRequestWrapper        private byte   body       public MyContentCachingRequestWrapper HttpServletRequest request  throws IOException           super request           super getParameterMap       init cache in ContentCachingRequestWrapper         body   super getContentAsByteArray       first option for application x-www-form-urlencoded         if  body length    0              try               body   IOUtils toByteArray super getInputStream        second option for other body formats             catch  IOException ex                body   new byte 0                                    public byte   getBody             return body              Override     public ServletInputStream getInputStream             return new RequestCachingInputStream body               Override     public BufferedReader getReader   throws IOException           return new BufferedReader new InputStreamReader getInputStream    getCharacterEncoding                 private static class RequestCachingInputStream extends ServletInputStream            private final ByteArrayInputStream inputStream           public RequestCachingInputStream byte   bytes                inputStream   new ByteArrayInputStream bytes                       Override         public int read   throws IOException               return inputStream read                        Override         public boolean isFinished                 return inputStream available      0                      Override         public boolean isReady                 return true                      Override         public void setReadListener ReadListener readlistener

[java] Http Servlet request lose params from POST body after read it once

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