We have tasks in java web-app that take a long time in completing and before the time the task completes the request times out and page cannot be displayed happens. We are think of setting a async redirection servlet that acts as a front-controller redirecting the request to the appropriate action classes and while the request is being served the servlet keeps sending a heartbeat every minute or so, until the request is completed by the corresponding action classes. Has anybody implemented something similar using asynchronous servlet 3.0? Also is this possible? I understand that this is similar to server push. Thanks for guidance.
yes this kind of functionality you can achive by use of
asynchronous servlet 3.0.it basically works like push
notification and also give you respose continously with
out making request here i have one code that i share with
this code may help for you to make async request.
this example check live users
#WebServlet(urlPatterns = { "/checkliveuser" }, asyncSupported = true)
public class CheckLiveUser extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final Queue<AsyncContext> queue = new ConcurrentLinkedQueue();
private static final BlockingQueue<String> messageQueue = new LinkedBlockingQueue();
private static final String BEGIN_SCRIPT_TAG = "<script type='text/javascript'>\n";
private static final String END_SCRIPT_TAG = "</script>\n";
private Thread notifierThread = null;
#Override
public void init(ServletConfig config) throws ServletException {
ServletContext context = config.getServletContext();
Set<String> users = new HashSet<String>();
Map<String, String> page = new HashMap<String, String>();
context.setAttribute("page", page);
context.setAttribute("messageQueue", messageQueue);
Runnable notifierRunnable = new Runnable() {
public void run() {
boolean done = false;
while (!done) {
System.out.println("in thread");
String cMessage = null;
try {
cMessage = BEGIN_SCRIPT_TAG + toJsonp("<b>Live User:", messageQueue.take())
+ END_SCRIPT_TAG;
for (AsyncContext ac : queue) {
try {
PrintWriter acWriter = ac.getResponse()
.getWriter();
acWriter.println(cMessage);
acWriter.flush();
} catch (IOException ex) {
System.out.println(ex);
queue.remove(ac);
}
}
} catch (InterruptedException iex) {
done = true;
System.out.println(iex);
}
}
}
};
notifierThread = new Thread(notifierRunnable);
notifierThread.start();
}
/**
* #see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter writer = response.getWriter();
request.setAttribute("org.apache.catalina.ASYNC_SUPPORTED", true);
final AsyncContext ac = request.startAsync();
ac.setTimeout(10 * 60 * 1000 * 1000);
ac.addListener(new AsyncListener() {
public void onComplete(AsyncEvent event) throws IOException {
queue.remove(ac);
System.out.println("on complete");
}
public void onTimeout(AsyncEvent event) throws IOException {
queue.remove(ac);
System.out.println("on timeout");
}
public void onError(AsyncEvent event) throws IOException {
queue.remove(ac);
System.out.println("on error");
}
public void onStartAsync(AsyncEvent event) throws IOException {
System.out.println("on startup");
}
});
queue.add(ac);
}
/**
* #see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/plain");
response.setCharacterEncoding("UTF-8");
ServletContext context = request.getServletContext();
HttpSession session = request.getSession();
Map<String, String> logins = (Map<String, String>) context
.getAttribute("page");
if (request.getParameter("action") != null
&& !request.getParameter("action").isEmpty()) {
if (request.getParameter("action").equalsIgnoreCase("logout")) {
logins.remove(request.getSession().getId());
request.getSession().invalidate();
}
}
String name = request.getParameter("loginID");
if (name != null) {
session.setAttribute("user", name);
session.setAttribute("jsessionId", session.getId());
logins.put(session.getId(), name);
}
String html = "";
for (Map.Entry<String, String> entry : logins.entrySet()) {
System.out.println("Key : " + entry.getKey() + " Value : "
+ entry.getValue());
html += entry.getValue() + "<br>";
}
String cMessage = BEGIN_SCRIPT_TAG + toJsonp("<b>Live User:", html)
+ END_SCRIPT_TAG;
notify(cMessage);
response.getWriter().println("success");
if (request.getParameter("action") != null
&& !request.getParameter("action").isEmpty()) {
if (request.getParameter("action").equalsIgnoreCase("logout"))
response.sendRedirect("login.jsp");
} else {
response.sendRedirect("welcome.jsp");
}
}
#Override
public void destroy() {
queue.clear();
notifierThread.interrupt();
}
private void notify(String cMessage) throws IOException {
try {
messageQueue.put(cMessage);
} catch (Exception ex) {
IOException t = new IOException();
t.initCause(ex);
throw t;
}
}
private String escape(String orig) {
StringBuffer buffer = new StringBuffer(orig.length());
for (int i = 0; i < orig.length(); i++) {
char c = orig.charAt(i);
switch (c) {
case '\b':
buffer.append("\\b");
break;
case '\f':
buffer.append("\\f");
break;
case '\n':
buffer.append("<br />");
break;
case '\r':
// ignore
break;
case '\t':
buffer.append("\\t");
break;
case '\'':
buffer.append("\\'");
break;
case '\"':
buffer.append("\\\"");
break;
case '\\':
buffer.append("\\\\");
break;
case '<':
buffer.append("<");
break;
case '>':
buffer.append(">");
break;
case '&':
buffer.append("&");
break;
default:
buffer.append(c);
}
}
return buffer.toString();
}
private String toJsonp(String name, String message) {
return "window.parent.app.update({ name: \"" + escape(name)
+ "\", message: \"" + escape(message) + "\" });\n";
}
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I'm having a few problems with two switches from a servlet. I'm trying to load data from those switches on a jsp but it basically just gets on the first switch and the second one isn't executed. I've tried creating only one switch but it will give me errors like Cannot forward after response has been committed and so on. Do you guys know what is the correct approach for this problem?
Thanks!
This is the code:
public class UserControllerServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private UserDao userDao;
private ReservationDao reservationDao;
private DBConnection dbConnection;
#Override
public void init() throws ServletException {
super.init();
try {
userDao = new UserDao(dbConnection);
reservationDao = new ReservationDao(dbConnection);
}catch(Exception e) {
throw new ServletException(e);
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
try {
// read the "command" parameter
String theCommand = request.getParameter("command");
String theCommand2 = request.getParameter("command2");
if(theCommand == null) {
theCommand = "LIST";
}
if(theCommand2 == null) {
theCommand2 = "LIST";
}
switch(theCommand2) {
case "LIST":
listReservations(request, response);
return;
case "ADD":
addReservation(request, response);
return;
case "LOAD":
loadReservation(request, response);
return;
case "UPDATE":
updateReservation(request, response);
return;
case "DELETE":
deleteReservation(request, response);
return;
default:
listReservations(request, response);
}
//route to the appropriate method
switch(theCommand) {
case "LIST":
listUsers(request, response);
break;
case "ADD":
addUser(request, response);
break;
case "LOAD":
loadUser(request, response);
break;
case "UPDATE":
updateUser(request, response);
break;
case "DELETE":
deleteUser(request, response);
break;
default:
listUsers(request, response);
}
}catch(Exception e) {
throw new ServletException(e);
}
}
private void deleteUser(HttpServletRequest request, HttpServletResponse response)
throws Exception {
String theUserId = request.getParameter("userId");
userDao.deleteUser(theUserId);
listUsers(request, response);
}
private void updateUser(HttpServletRequest request, HttpServletResponse response)
throws Exception {
int id = Integer.parseInt(request.getParameter("userId"));
String username = request.getParameter("username");
String password = request.getParameter("password");
String role = request.getParameter("role");
String nume = request.getParameter("nume");
String prenume = request.getParameter("prenume");
String email = request.getParameter("email");
String adresa = request.getParameter("adresa");
UserBean theUser = new UserBean(id, username, password, role,nume,prenume,email,adresa);
userDao.updateUser(theUser);
listUsers(request, response);
}
private void loadUser(HttpServletRequest request, HttpServletResponse response) throws Exception {
String theUserId = request.getParameter("userId");
UserBean theUser = userDao.getUser(theUserId);
request.setAttribute("THE_USER", theUser);
RequestDispatcher dispatcher =
request.getRequestDispatcher("/update-user-form.jsp");
dispatcher.forward(request, response);
return;
}
private void addUser(HttpServletRequest request, HttpServletResponse response) throws Exception {
String username = request.getParameter("username");
String password = request.getParameter("password");
String role = request.getParameter("role");
String nume = request.getParameter("nume");
String prenume = request.getParameter("prenume");
String email = request.getParameter("email");
String adresa = request.getParameter("adresa");
UserBean theUser = new UserBean(username, password, role,nume,prenume,email,adresa);
userDao.addUser(theUser);
listUsers(request, response);
}
private void listUsers(HttpServletRequest request, HttpServletResponse response)
throws Exception {
List<UserBean> users = userDao.getUsers();
request.setAttribute("USER_LIST", users);
RequestDispatcher dispatcher = request.getRequestDispatcher("/list-users.jsp");
dispatcher.forward(request, response);
return;
}
//Reservations Methods
private void deleteReservation(HttpServletRequest request, HttpServletResponse response)
throws Exception {
String theReservationId = request.getParameter("reservationId");
reservationDao.deleteReservation(theReservationId);
listReservations(request, response);
}
private void updateReservation(HttpServletRequest request, HttpServletResponse response)
throws Exception {
int idReservation = Integer.parseInt(request.getParameter("reservationId"));
int idUser = Integer.parseInt(request.getParameter("userId"));
String dataCheckin = request.getParameter("dataCheckin");
String dataCheckout = request.getParameter("dataCheckout");
int nrPersoane = Integer.parseInt(request.getParameter("nrPersoane"));
int nrCamere = Integer.parseInt(request.getParameter("nrCamere"));
ReservationBean theReservation = new ReservationBean(idReservation, idUser, dataCheckin, dataCheckout,nrPersoane,nrCamere);
reservationDao.updateReservation(theReservation);
listReservations(request, response);
}
private void loadReservation(HttpServletRequest request, HttpServletResponse response) throws Exception {
String theReservationId = request.getParameter("reservationId");
ReservationBean theReservation = reservationDao.getReservation(theReservationId);
request.setAttribute("THE_RESERVATION", theReservation);
RequestDispatcher dispatcher =
request.getRequestDispatcher("/update-reservation-form.jsp");
dispatcher.forward(request, response);
return;
}
private void addReservation(HttpServletRequest request, HttpServletResponse response) throws Exception {
int userId = Integer.parseInt(request.getParameter("userId"));
String dataCheckin = request.getParameter("dataCheckin");
String dataCheckout = request.getParameter("dataCheckout");
int nrPersoane = Integer.parseInt(request.getParameter("nrPersoane"));
int nrCamere = Integer.parseInt(request.getParameter("nrCamere"));
ReservationBean theReservation = new ReservationBean(userId, dataCheckin, dataCheckout,nrPersoane,nrCamere);
reservationDao.addReservation(theReservation);
listReservations(request, response);
}
private void listReservations(HttpServletRequest request, HttpServletResponse response)
throws Exception {
List<ReservationBean> reservations = reservationDao.getReservations();
request.setAttribute("RESERVATION_LIST", reservations);
request.getRequestDispatcher("/list-users.jsp").forward(request, response);
return;
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
gets on the first switch and the second one isn't executed
Your first switch contains return statements. Change them to break statements.
switch(theCommand2) {
case "LIST":
listReservations(request, response);
break; // not return.
case "ADD":
addReservation(request, response);
break; // not return..
// ...
I want to print a document in my java web application using servlet and i clear report info to avoid download resume(SecurityContext.cleanReportInfo()).
everything is ok when you don't have IDM in your system but when IDM is running it sends 2 request instead 1 and everything goes wrong by redirecting to /403 like the code below .
PrintReportServlet
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ReportDto reportInfo = SecurityContext.getReportInfo();
if (reportInfo != null) {
ServletOutputStream outputStream = response.getOutputStream();
try {
generateHeaders(response, reportInfo);
generateContents(outputStream, reportInfo);
} catch (Exception e) {
LOGGER.log(Level.WARNING, "Error occurred during print report, nested error message: {0}", e.getMessage());
} finally {
outputStream.flush();
outputStream.close();
SecurityContext.cleanReportInfo();
}
} else {
response.sendRedirect(request.getContextPath() + "/403");
}
}
SecurityContext.java
public static void cleanReportInfo() {
SecurityContext.getCurrentSession().setAttribute("Report_Info", null);
}
errorreportController.js
$scope.printErrorList = function () {
errorReportService.printErrorList(function () {
window.open(contextPath + "/PrintReport");
});
};
ErrorReportController.java
#RequestMapping(value = "/printError", method = RequestMethod.GET)
#ResponseBody
public String printError() {
ReportDto reportDto = errorReportService.getReportInfo();
SecurityContext.setReportInfo(reportDto);
return success();
}
ErrorReportServiceImpl
public ReportDto getReportInfo() {
Map<String, Object> parameters = new HashMap<String, Object>();
parameters.put("jalaliDate", DateUtil.convertToJalali(new Date()).toStringBySlash());
parameters.put("alahImagePath", ReportUtil.getImagesPath() + File.separator + "alah.png");
parameters.put("sepahImagePath", ReportUtil.getImagesPath() + File.separator + "sepah.png");
parameters.put("reporter", SecurityContext.getCurrentUserName());
parameters.put("classify", "Normal");
parameters.put("userId",SecurityContext.getCurrentUserId());
ReportDto reportDto = new ReportDto(
ReportNames.ErrorReport, DataItems.Report_Type_PDF,
"error",
parameters);
return reportDto;
}
I have some data in the form of XML which contains few records and also created one RPT file.
So now, how can i call birt to generate report by passing XML and RPT as input parameters.
I am completely new to BIRT. Any code example wil be appreciated.
try this:BirtEngine.java:
public class BirtEngine {
private static IReportEngine birtEngine = null;
private static Properties configProps = new Properties();
private final static String configFile = "BirtConfig.properties";
public static synchronized void initBirtConfig() {
loadEngineProps();
}
public static synchronized IReportEngine getBirtEngine(ServletContext sc) {
if (birtEngine == null)
{
EngineConfig config = new EngineConfig();
if( configProps != null){
String logLevel = configProps.getProperty("logLevel");
Level level = Level.OFF;
if ("SEVERE".equalsIgnoreCase(logLevel))
{
level = Level.SEVERE;
} else if ("WARNING".equalsIgnoreCase(logLevel))
{
level = Level.WARNING;
} else if ("INFO".equalsIgnoreCase(logLevel))
{
level = Level.INFO;
} else if ("CONFIG".equalsIgnoreCase(logLevel))
{
level = Level.CONFIG;
} else if ("FINE".equalsIgnoreCase(logLevel))
{
level = Level.FINE;
} else if ("FINER".equalsIgnoreCase(logLevel))
{
level = Level.FINER;
} else if ("FINEST".equalsIgnoreCase(logLevel))
{
level = Level.FINEST;
} else if ("OFF".equalsIgnoreCase(logLevel))
{
level = Level.OFF;
}
config.setLogConfig(configProps.getProperty("logDirectory"), level);
}
config.setEngineHome("");
IPlatformContext context = new PlatformServletContext( sc );
//IPlatformContext context = new PlatformFileContext();
config.setPlatformContext( context );
//Create the report engine
//birtEngine = new ReportEngine( config );
//ReportEngine engine = new ReportEngine( null );
try
{
Platform.startup( config );
}
catch ( BirtException e )
{
e.printStackTrace( );
}
IReportEngineFactory factory = (IReportEngineFactory) Platform
.createFactoryObject( IReportEngineFactory.EXTENSION_REPORT_ENGINE_FACTORY );
birtEngine = factory.createReportEngine( config );
}
return birtEngine;
}
public static synchronized void destroyBirtEngine() {
if (birtEngine == null) {
return;
}
birtEngine.destroy();
Platform.shutdown();
birtEngine = null;
}
public Object clone() throws CloneNotSupportedException {
throw new CloneNotSupportedException();
}
private static void loadEngineProps() {
try {
//Config File must be in classpath
ClassLoader cl = Thread.currentThread ().getContextClassLoader();
InputStream in = null;
in = cl.getResourceAsStream (configFile);
configProps.load(in);
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
webreport.java:
public class WebReport extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
/**
* Constructor of the object.
*/
private IReportEngine birtReportEngine = null;
protected static Logger logger = Logger.getLogger( "org.eclipse.birt" );
public WebReport() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy();
BirtEngine.destroyBirtEngine();
}
/**
* The doGet method of the servlet. <br>
*
*/
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
//get report name and launch the engine
//resp.setContentType("text/html");
//resp.setContentType( "application/pdf" );
resp.setContentType( "application/msword" );
//resp.setHeader ("Content-Disposition","inline; filename=test.pdf");
resp.setHeader("Content-disposition","attachment; filename=\"" +"test.doc" +"\"");
String reportName = req.getParameter("ReportName");
ServletContext sc = req.getSession().getServletContext();
this.birtReportEngine = BirtEngine.getBirtEngine(sc);
IReportRunnable design;
try
{
//Open report design
design = birtReportEngine.openReportDesign( sc.getRealPath("/Reports")+"/"+reportName );
//create task to run and render report
IRunAndRenderTask task = birtReportEngine.createRunAndRenderTask( design );
task.getAppContext().put(EngineConstants.APPCONTEXT_CLASSLOADER_KEY, WebReport.class.getClassLoader());
task.getAppContext().put("BIRT_VIEWER_HTTPSERVLET_REQUEST", req );
//set output options
//HTMLRenderOption options = new HTMLRenderOption();
//options.setOutputFormat(HTMLRenderOption.OUTPUT_FORMAT_HTML);
//options.setOutputStream(resp.getOutputStream());
//options.setImageHandler(new HTMLServerImageHandler());
//options.setBaseImageURL(req.getContextPath()+"/images");
//options.setImageDirectory(sc.getRealPath("/images"));
/*PDFRenderOption options = new PDFRenderOption();
options.setOutputFormat(HTMLRenderOption.OUTPUT_FORMAT_PDF);
options.setOutputStream(resp.getOutputStream());
*/
RenderOption options = new RenderOption();
options.setOutputFormat("doc");
options.setOutputStream(resp.getOutputStream());
//options.setEnableAgentStyleEngine(true);
//options.setEnableInlineStyle(true);
task.setRenderOption(options);
//run report
task.run();
task.close();
}catch (Exception e){
e.printStackTrace();
throw new ServletException( e );
}
}
/**
* The doPost method of the servlet. <br>
*
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.println(" Post Not Supported");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* #throws ServletException if an error occure
*/
public void init(ServletConfig sc) throws ServletException {
BirtEngine.initBirtConfig();
this.birtReportEngine = BirtEngine.getBirtEngine(sc.getServletContext());
}
}
birtconfigproperty:
ogDirectory=c:/temp
logLevel=FINEST
I'm modeling a controller reflection based. I would like to know if you agree my implementation and what could to be enhanced.
I'm starting with reflection and I would like to know if I'm using good practices.
Sample: www.sample.com/Main?mvc=user/edit/5
See it:
public class StartController extends HttpServlet {
#Override
public void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
String vars = req.getParameter("mvc");
ApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(getServletContext());
MainController main = new MainController();
main.RESTProcess(req, resp, context, vars);
}
}
public class MainController extends Controller {
public void RESTProcess(HttpServletRequest req, HttpServletResponse resp, ApplicationContext context, String vars)
throws IOException, ServletException
{
String[] url;
int nvars;
String controller = null;
String action = null;;
String[] params = null;
int i;
int n;
String controllerName;
String actionName;
if(vars == null || "".equals(vars.trim()))
{
this.redirect(resp,"home");
}
else
{
url = vars.split("/");
nvars = url.length;
if(nvars > 0)
{
controller = url[0].trim(); //users
if(nvars > 1)
{
action = url[1].trim(); //edit
if(nvars > 2)
{
n = 0;
params = new String[nvars - 2]; //array[0] = 5 (iduser)
for(i = 2; i < nvars; i++)
{
params[n] = url[i];
n++;
}
}
}
controllerName = this.getFirstUpper(controller) + "Controller"; //HomeController, UserController pattern
if(!controllerName.equals("Controller"))
{
actionName = "action" + this.getFirstUpper(action); //actionIndex, actionEdit pattern
if(!action.equals("action"))
{
try
{
Class classe = Class.forName("com.sample.controller." + controllerName);
try
{
Constructor c = classe.getConstructor(HttpServletRequest.class, HttpServletResponse.class, String[].class);
try
{
Object obj = c.newInstance(req, resp, context, params);
Method m = classe.getMethod(actionName, null);
m.invoke(obj, null);
System.out.println(obj.toString());
}
catch (Exception e)
{
e.printStackTrace();
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
}
else
{
this.redirect(resp,"home");
}
}
}
public String getFirstUpper(String str)
{
Integer x = str.length();
str = str.substring(0,1).toUpperCase().concat(str.substring(1, x));
return str;
}
}
public class UserController extends Controller {
private HttpServletRequest req;
private HttpServletResponse resp;
private ApplicationContext context;
private String[] params;
public UserController(HttpServletRequest req, HttpServletResponse resp, ApplicationContext context, String[] params)
{
this.req = req;
this.resp = resp;
this.context = context;
this.params = params;
}
public void actionEdit()
{
Long id = Long.valueOf(this.params[0]);
System.out.println("/home/edit");
}
}
I am trying to get the whole body from the HttpServletRequest object.
The code I am following looks like this:
if ( request.getMethod().equals("POST") )
{
StringBuffer sb = new StringBuffer();
BufferedReader bufferedReader = null;
String content = "";
try {
//InputStream inputStream = request.getInputStream();
//inputStream.available();
//if (inputStream != null) {
bufferedReader = request.getReader() ; //new BufferedReader(new InputStreamReader(inputStream));
char[] charBuffer = new char[128];
int bytesRead;
while ( (bytesRead = bufferedReader.read(charBuffer)) != -1 ) {
sb.append(charBuffer, 0, bytesRead);
}
//} else {
// sb.append("");
//}
} catch (IOException ex) {
throw ex;
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException ex) {
throw ex;
}
}
}
test = sb.toString();
}
and I am testing the functionality with curl and wget as follows:
curl --header "MD5: abcd" -F "fileupload=#filename.txt http://localhost:8080/abcd.html"
wget --header="MD5: abcd" --post-data='{"imei":"351553012623446","hni":"310150","wdp":false}' http://localhost:8080/abcd.html"
But the while ( (bytesRead = bufferedReader.read(charBuffer)) != -1 ) does not return anything, and so I get nothing appended on StringBuffer.
In Java 8, you can do it in a simpler and clean way :
if ("POST".equalsIgnoreCase(request.getMethod()))
{
test = request.getReader().lines().collect(Collectors.joining(System.lineSeparator()));
}
Easy way with commons-io.
IOUtils.toString(request.getReader());
https://commons.apache.org/proper/commons-io/javadocs/api-2.5/org/apache/commons/io/IOUtils.html
Be aware, that your code is quite noisy.
I know the thread is old, but a lot of people will read it anyway.
You could do the same thing using the guava library with:
if ("POST".equalsIgnoreCase(request.getMethod())) {
test = CharStreams.toString(request.getReader());
}
If all you want is the POST request body, you could use a method like this:
static String extractPostRequestBody(HttpServletRequest request) throws IOException {
if ("POST".equalsIgnoreCase(request.getMethod())) {
Scanner s = new Scanner(request.getInputStream(), "UTF-8").useDelimiter("\\A");
return s.hasNext() ? s.next() : "";
}
return "";
}
Credit to: https://stackoverflow.com/a/5445161/1389219
This works for both GET and POST:
#Context
private HttpServletRequest httpRequest;
private void printRequest(HttpServletRequest httpRequest) {
System.out.println(" \n\n Headers");
Enumeration headerNames = httpRequest.getHeaderNames();
while(headerNames.hasMoreElements()) {
String headerName = (String)headerNames.nextElement();
System.out.println(headerName + " = " + httpRequest.getHeader(headerName));
}
System.out.println("\n\nParameters");
Enumeration params = httpRequest.getParameterNames();
while(params.hasMoreElements()){
String paramName = (String)params.nextElement();
System.out.println(paramName + " = " + httpRequest.getParameter(paramName));
}
System.out.println("\n\n Row data");
System.out.println(extractPostRequestBody(httpRequest));
}
static String extractPostRequestBody(HttpServletRequest request) {
if ("POST".equalsIgnoreCase(request.getMethod())) {
Scanner s = null;
try {
s = new Scanner(request.getInputStream(), "UTF-8").useDelimiter("\\A");
} catch (IOException e) {
e.printStackTrace();
}
return s.hasNext() ? s.next() : "";
}
return "";
}
If the request body is empty, then it simply means that it's already been consumed beforehand. For example, by a request.getParameter(), getParameterValues() or getParameterMap() call. Just remove the lines doing those calls from your code.
This will work for all HTTP method.
public class HttpRequestWrapper extends HttpServletRequestWrapper {
private final String body;
public HttpRequestWrapper(HttpServletRequest request) throws IOException {
super(request);
body = IOUtils.toString(request.getReader());
}
#Override
public ServletInputStream getInputStream() throws IOException {
final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(getBody().getBytes());
ServletInputStream servletInputStream = new ServletInputStream() {
public int read() throws IOException {
return byteArrayInputStream.read();
}
#Override
public boolean isFinished() {
return false;
}
#Override
public boolean isReady() {
return false;
}
#Override
public void setReadListener(ReadListener listener) {
}
};
return servletInputStream;
}
public String getBody() {
return this.body;
}
}
Easiest way I could think of:
request.getReader().lines().reduce("",String::concat)
However, this will be one long string which you will have to parse. IF you send a username of tim and a password of 12345. The output of the code above would look like this:
{ "username":"tim", "password": "12345"}
Please be aware
Please be aware that with the reduce() method we are performing a Mutable Reduction which does a great deal of string copying and has a runtime of O(N^2) with N being the number of characters. Please check the Mutable Reduction documentation if you need a more performant result.
I resolved that situation in this way. I created a util method that return a object extracted from request body, using the readValue method of ObjectMapper that is capable of receiving a Reader.
public static <T> T getBody(ResourceRequest request, Class<T> class) {
T objectFromBody = null;
try {
ObjectMapper objectMapper = new ObjectMapper();
HttpServletRequest httpServletRequest = PortalUtil.getHttpServletRequest(request);
objectFromBody = objectMapper.readValue(httpServletRequest.getReader(), class);
} catch (IOException ex) {
log.error("Error message", ex);
}
return objectFromBody;
}
I personnally use this code (on a dev server, not in production). Seems to work. The main difficulty is that once you read the request body, it will be lost and not transferred to the app. So you have to "cache" it first.
/* Export this filter as a jar and place it under directory ".../tomcat/lib" on your Tomcat server/
In the lib directory, also place the dependencies you need
(ex. org.apache.commons.io => commons-io-2.8.0.jar)
Once this is done, in order to activate the filter, on the Tomcat server:
o in .../tomcat/conf/server.xml, add:
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" prefix="localhost_access_log" suffix=".txt" pattern="%h %l %u %t "%r" [%{postdata}r] %s %b"/>
=> the server will log the "postdata" attribute we generate in the Java code.
o in .../tomcat/conf/web.xml, add:
<filter>
<filter-name>post-data-dumper-filter</filter-name>
<filter-class>filters.PostDataDumperFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>post-data-dumper-filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
Once you've done this, restart your tomcat server. You will get extra infos in file "localhost_access_log.<date>.txt"
*/
package filters;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Enumeration;
import java.util.stream.Collectors;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import org.apache.commons.io.IOUtils;
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.
*/
cachedBytes = new ByteArrayOutputStream();
IOUtils.copy(super.getInputStream(), cachedBytes);
}
/* An input stream 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 boolean isFinished() {
return input.available() == 0;
}
#Override
public boolean isReady() {
return true;
}
//---------------------
#Override
public void setReadListener(ReadListener arg0) {
// TODO Auto-generated method stub
// Ex. : throw new RuntimeException("Not implemented");
}
}
}
public final class PostDataDumperFilter implements Filter {
private FilterConfig filterConfig = null;
public void destroy() {
this.filterConfig = null;
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
if (filterConfig == null)
return;
StringBuffer output = new StringBuffer();
output.append("PostDataDumperFilter-");
/* Wrap the request in order to be able to read its body multiple times */
MultiReadHttpServletRequest multiReadRequest = new MultiReadHttpServletRequest((HttpServletRequest) request);
// TODO : test the method in order not to log the body when receiving GET/DELETE requests ?
// I finally leave it "as it", since I've seen GET requests containing bodies (hell...).
output.append("Content-type=" + multiReadRequest.getContentType());
output.append(" - HTTP Method=" + multiReadRequest.getMethod());
output.append(" - REQUEST BODY = " + multiReadRequest.getReader().lines().collect(Collectors.joining(System.lineSeparator())));
// Log the request parameters:
Enumeration names = multiReadRequest.getParameterNames();
if (names.hasMoreElements()) {
output.append("- REQUEST PARAMS = ");
}
while (names.hasMoreElements()) {
String name = (String) names.nextElement();
output.append(name + "=");
String values[] = multiReadRequest.getParameterValues(name);
for (int i = 0; i < values.length; i++) {
if (i > 0) output.append("' ");
output.append(values[i]);
}
if (names.hasMoreElements()) output.append("&");
}
multiReadRequest.setAttribute("postdata", output);
chain.doFilter(multiReadRequest, response);
}
public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
}
}