Comment lire demande.getInputStream() plusieurs fois

Code de travail basé sur la accepté de répondre.

public class CustomHttpServletRequestWrapper extends HttpServletRequestWrapper {
private static final Logger logger = Logger.getLogger(CustomHttpServletRequestWrapper.class);
private final String body;
public CustomHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
StringBuilder stringBuilder = new StringBuilder();  
BufferedReader bufferedReader = null;  
try {  
InputStream inputStream = request.getInputStream(); 
if (inputStream != null) {  
bufferedReader = new BufferedReader(new InputStreamReader(inputStream));  
char[] charBuffer = new char[128];  
int bytesRead = -1;  
while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {  
stringBuilder.append(charBuffer, 0, bytesRead);  
}  
} else {  
stringBuilder.append("");  
}  
} catch (IOException ex) {  
logger.error("Error reading the request body...");  
} finally {  
if (bufferedReader != null) {  
try {  
bufferedReader.close();  
} catch (IOException ex) {  
logger.error("Error closing bufferedReader...");  
}  
}  
}  
body = stringBuilder.toString();  
}
@Override  
public ServletInputStream getInputStream () throws IOException {          
final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body.getBytes());
ServletInputStream inputStream = new ServletInputStream() {  
public int read () throws IOException {  
return byteArrayInputStream.read();  
}  
};
return inputStream;  
} 
}

Pour Servlet 3.1

class MyHttpServletRequestWrapper extends HttpServletRequestWrapper {
private byte[] body;
public MyHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
try {
body = IOUtils.toByteArray(request.getInputStream());
} catch (IOException ex) {
body = new byte[0];
}
}
@Override
public ServletInputStream getInputStream() throws IOException {
new DelegatingServletInputStream(new ByteArrayInputStream(body));
}
}
public class DelegatingServletInputStream extends ServletInputStream {
private final InputStream sourceStream;
private boolean finished = false;
/**
* Create a DelegatingServletInputStream for the given source stream.
*
* @param sourceStream the source stream (never {@code null})
*/
public DelegatingServletInputStream(InputStream sourceStream) {
this.sourceStream = sourceStream;
}
/**
* Return the underlying source stream (never {@code null}).
*/
public final InputStream getSourceStream() {
return this.sourceStream;
}
@Override
public int read() throws IOException {
int data = this.sourceStream.read();
if (data == -1) {
this.finished = true;
}
return data;
}
@Override
public int available() throws IOException {
return this.sourceStream.available();
}
@Override
public void close() throws IOException {
super.close();
this.sourceStream.close();
}
@Override
public boolean isFinished() {
return this.finished;
}
@Override
public boolean isReady() {
return true;
}
@Override
public void setReadListener(ReadListener readListener) {
throw new UnsupportedOperationException();
}
}

demande.getInputStream() est autorisé à lire qu'une seule fois. Afin d'utiliser cette méthode plusieurs fois, nous avons besoin de faire supplémentaire de la tâche personnalisée pour HttpServletReqeustWrapper classe. voir mon exemple de classe wrapper ci-dessous.

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();
}
}
}

Dans mon cas, je faire le suivi de toutes les demandes entrantes dans le journal. J'ai créé un Filtre

public class TracerRequestFilter implémente Filtre {
private static final de l'Enregistreur de JOURNAL = LoggerFactory.getLogger(TracerRequestFilter.class);

@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
ServletException {
final HttpServletRequest req = (HttpServletRequest) request;
try {
if (LOG.isDebugEnabled()) {
final MultiReadHttpServletRequest wrappedRequest = new MultiReadHttpServletRequest(req);
//debug payload info
logPayLoad(wrappedRequest);
chain.doFilter(wrappedRequest, response);
} else {
chain.doFilter(request, response);
}
} finally {
LOG.info("end-of-process");
}
}
private String getRemoteAddress(HttpServletRequest req) {
String ipAddress = req.getHeader("X-FORWARDED-FOR");
if (ipAddress == null) {
ipAddress = req.getRemoteAddr();
}
return ipAddress;
}
private void logPayLoad(HttpServletRequest request) {
final StringBuilder params = new StringBuilder();
final String method = request.getMethod().toUpperCase();
final String ipAddress = getRemoteAddress(request);
final String userAgent = request.getHeader("User-Agent");
LOG.debug(String.format("============debug request=========="));
LOG.debug(String.format("Access from ip:%s;ua:%s", ipAddress, userAgent));
LOG.debug(String.format("Method : %s requestUri %s", method, request.getRequestURI()));
params.append("Query Params:").append(System.lineSeparator());
Enumeration<String> parameterNames = request.getParameterNames();
for (; parameterNames.hasMoreElements();) {
String paramName = parameterNames.nextElement();
String paramValue = request.getParameter(paramName);
if ("password".equalsIgnoreCase(paramName) || "pwd".equalsIgnoreCase(paramName)) {
paramValue = "*****";
}
params.append("---->").append(paramName).append(": ").append(paramValue).append(System.lineSeparator());
}
LOG.debug(params.toString());
/** request body */
if ("POST".equals(method) || "PUT".equals(method)) {
try {
LOG.debug(IOUtils.toString(request.getInputStream()));
} catch (IOException e) {
LOG.error(e.getMessage(), e);
}
}
LOG.debug(String.format("============End-debug-request=========="));
}
@Override
public void init(FilterConfig arg0) throws ServletException {
}
}

Il fonctionne pour moi Servlet 2.5 et 3.0. Je vois une demande tous les paramètres à la fois la forme codée et demande json corps.