The full error: java.lang.NoClassDefFoundError: Could not initialize class lt.maze.dao.DAO
The class DAO is used from my LoginServlet. It is compiled and deployed, I checked WEB-INF/classes. DAO.class exists.
Why is isn't it loaded? Am I suppose to add them to my classpath manually? (I have the manifest file to load my properties file).
LoginServlet.java:
#WebServlet(name = "LoginServlet", urlPatterns = { "/login" })
public class LoginServlet extends HttpServlet {
#Override
public void init() throws ServletException
{
System.out.println("System. out. Its online.");
getServletContext().log("LoginServlet initialised");
}
#Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
getServletContext().log("Http request. Request URI: " + request.getRequestURI());
System.out.println("Http request. Request URI: " + request.getRequestURI());
String username = request.getParameter("username");
String password = request.getParameter("password");
if(username == null || password == null) {
response.sendError(401);
} else {
UserDAO userDAO = DAO.getUserDAO();
User user = userDAO.find(username, password);
if(user == null) {
response.sendError(401, "Invalid username or password");
} else {
String sessionToken = SessionTokens.getSessionToken();
response.addCookie(new Cookie("session-token", sessionToken));
getServletContext().log("Valid connection. token:"+sessionToken);
}
}
}
#Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
getServletContext().log("Request received via GET.");
System.out.println("Requeswt received via GET");
}
}
Full stacktrace:
18-May-2015 14:49:35.133 SEVERE [http-nio-8080-exec-1] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [LoginServlet] in context with path [/ChatApp] threw exception [Servlet execution threw an exception] with root cause
java.lang.NoClassDefFoundError: Could not initialize class lt.maze.dao.DAO
at lt.maze.LoginServlet.doPost(LoginServlet.java:38)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1517)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1474)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
If an exception is propagating out of the constructor of the class or a static initializer, then you also get java.lang.NoClassDefFoundError: Could not initialize class ... .
Related
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 4 years ago.
Create a servlet that uses cookies to store the number how many times user has visited?-That's the question im trying to solve
this is my html
<html>
<head>
</head>
<body>
<form action="NewServlet">
<input type="text" name="text1">
<input type="submit"/>
</form>
</body>
</html>
this is NewServlet.java
public class NewServlet extends HttpServlet {
public void service(HttpServletRequest req,HttpServletResponse res)throws
IOException,ServletException
{
res.setContentType("text/html");
Cookie[] cook=req.getCookies();
String s=req.getParameter("text1");
int a=0;
if(cook.length>0)
{
for(Cookie cookie :cook)
{
if(cookie.getName().equals(s))
{
int b=Integer.parseInt(cookie.getValue());
b=b+1;
cookie.setValue(String.valueOf(b));
a++;
}
}
}
if(a>0)
{
res.sendRedirect("NewServlet1");
}
else
{
Cookie cok=new Cookie(s,"1");
res.addCookie(cok);
req.setAttribute("user", s);
RequestDispatcher r=req.getRequestDispatcher("NewServlet1");
r.forward(req,res);
}
}
}
and this is NewServlet1.java
public class NewServlet1 extends HttpServlet {
protected void service(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
res.setContentType("text/html;charset=UTF-8");
Cookie[] cookie=req.getCookies();
String s=String.valueOf(req.getAttribute("user"));
for(Cookie cok:cookie)
{
if(cok.getName().equals(s))
{
int a=Integer.parseInt(cok.getValue());
res.getWriter().println("number of times visited"+a);
}
}
}
}
what i am doing is checking if cookie exist or not and if no then creating the cookie on NewServlet.java .But i am getting a Null-Pointer Exception (Error 500)
on clicking the submit button
stacktrace
at First.NewServlet.service(NewServlet.java:28)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:217)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
Change if(cook.length>0) to if(cook !=null && cook.length > 0). This way if cook is null then it will not check the .length and hence avoid the NPE
I have some code for download file from web server.
Everything works alright, but in console I have this exception:
июн 26, 2015 2:08:42 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [default] in context with path [/TestTask] threw exception
java.lang.IllegalStateException: Cannot call sendError() after the response has been committed
at org.apache.catalina.connector.ResponseFacade.sendError(ResponseFacade.java:462)
at org.apache.struts2.dispatcher.DefaultDispatcherErrorHandler.handleErrorInDevMode(DefaultDispatcherErrorHandler.java:109)
at org.apache.struts2.dispatcher.DefaultDispatcherErrorHandler.handleError(DefaultDispatcherErrorHandler.java:57)
at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:909)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:576)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:526)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:655)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1566)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1523)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Why and what it can be? And how i can fix this problem? I try find answer in the google, but I failed.
The code:
package actions;
import java.io.IOException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import javax.xml.ws.Action;
import org.apache.log4j.Logger;
import org.apache.struts.chain.contexts.ServletActionContext;
import service.CsvCreator;
import com.opensymphony.xwork2.ActionSupport;
public class DownloadCsvAction extends ActionSupport {
private static final long serialVersionUID = -4714537109287679996L;
private CsvCreator CSVcreator;
private static final Logger logger = Logger.getLogger(DownloadCsvAction.class);
public CsvCreator getCSVcreator() {
return CSVcreator;
}
public void setCSVcreator(CsvCreator cSVcreator) {
CSVcreator = cSVcreator;
}
#Override
public String execute() {
HttpServletResponse response = org.apache.struts2.ServletActionContext.getResponse();
response.setHeader("Content-Disposition", "attachment; filename=\"phone_records.csv\"");
response.setContentType("text/csv");
ServletOutputStream out;
try {
out = response.getOutputStream();
String tableHeader = "Caller, Event, Reciever, Timestamp\n";
out.write(tableHeader.getBytes("UTF-8"));
out.write(CSVcreator.getAllRecordsInString().getBytes("UTF-8"));
out.flush();
out.close();
} catch (IOException e) {
logger.error(e.getMessage());
}
return SUCCESS;
}
}
And my struts.xml:
<action name="DownloadCsvAction" class="DownloadCsvAction">
<result name="success" type="dispatcher"/>
</action>
Why and what it can be?
Because response is already committed. You have closed response before it's used by the Struts2.
And how I can fix this problem?
When your action execution ends, return Action.NONE result code. This code tells the invoker to not execute any result because response might be already committed.
You can also rewrite the action implementation to use stream result type. In this way you have not to do with the response and let Struts2 do the rest. Example of using stream result is here.
This question already has answers here:
java.lang.IllegalStateException: Cannot (forward | sendRedirect | create session) after response has been committed
(9 answers)
Closed 6 years ago.
I am trying to catch exception in servlet filter and the forward to an error page.
But when I catched the exception in filter and using request.getRequestDispatcher("/error.html").forward(request, response); to forward to the error page it is throwing me the error saying Cannot forward after response has been committed.
Code:
public class TestFilter implements Filter {
private String encoding = null;
public void destroy() {
encoding = null;
}
#Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
// TODO Auto-generated method stub
try {
chain.doFilter(request, response);
double value = 1/0;// to make an exception
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
request.getRequestDispatcher("/error.html").forward(request, response);
}
}
#Override
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
}
}
Stacktrace:
java.lang.ArithmeticException: / by zero
at com.baoming.filter.TestFilter.doFilter(TestFilter.java:27)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1085)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1556)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1513)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Jan 26, 2017 3:01:54 下午 org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [springmvc] in context with path [/Monitor] threw exception
java.lang.IllegalStateException: Cannot forward after response has been committed
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:328)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)
at com.baoming.filter.TestFilter.doFilter(TestFilter.java:31)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1085)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1556)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1513)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
I made the ArithmeticException to specify the problem. If I move the code double value = 1/0; before chain.doFilter(request, response);,it will not throw Cannot forward after response has been committed exception.
I don't know how to fix the problem. If an exception occurs after chain.doFilter(request, response);, how can I catch it and forward to another page?
just a guess: you need to swap chain.doFilter(request, response); and double value = 1/0; because at the moment you rise the exception after your servlet has done the work:
try {
double value = 1/0;// to make an exception
chain.doFilter(request, response);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
request.getRequestDispatcher("/error.html").forward(request, response);
}
i'm working on a project with Spring, i have this problem, i google the error message and i did find a solutions even all SO posts about this same problem
java.lang.IllegalStateException: "getOutputStream()" has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:578)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:212)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:109)
at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:115)
at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:108)
at org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:175)
at org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:120)
at org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:75)
at org.apache.jsp.WEB_002dINF.Pages.generate_jsp._jspService(generate_jsp.java:209)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:584)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:523)
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:230)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:250)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1060)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:798)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:716)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:647)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:552)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:617)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1521)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1478)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
this is my controller :
#RequestMapping(method = RequestMethod.GET, value = "/GenerateM")
public String genererGet(HttpServletRequest request, ModelMap model, HttpServletResponse response) throws Exception {
// Some code ...
OutputStream out;
try {
response.setContentType("rtf");
String filename = name + ".out.rtf";
response.setHeader("Content-Disposition", "attachment; filename = " + filename);
out = response.getOutputStream();
FileInputStream in = new FileInputStream(new File(rtf.getRtfOutput()));
byte[] buffer = new byte[4096];
int length;
while ((length = in.read(buffer)) > 0) {
out.write(buffer, 0, length);
}
in.close();
out.flush();
out.close();
} catch (IOException a) {
a.printStackTrace();
}
return "generate";
}
i saw many SO posts like : THIS and THIS and THIS but no solution for me
can some one help ?
You start by writing a response by yourself, and then return the name of the view, and thus telling Spring that it should generate an HTML page using the generate.jsp.
Make your method return void instead of a String. An HTTP response can have only one body: either it's a file attachment, or an HTML page, but not both.
#JB Nizet Thank's for help. In my case, I retured ModelAndView ojbect when download failing to forward error page:
#RequestMapping(value = { "/downloadfile.action" }, method = RequestMethod.POST)
public ModelAndView downloadFile(HttpServletRequest req, HttpServletResponse res, Model model)
{
catch (Excetion e) {
return errorPage
}
}
I change that to return null
This question already has an answer here:
java.lang.IllegalStateException: Cannot forward after response has been committed in servlet [duplicate]
(1 answer)
Closed 7 years ago.
I am trying to learn abt servlets.
I am getting a IllegalStateException when i call forward(). The error occurs in the LoginBean.do if block at the point where i call forward.
process(request,response);
}
private void process(HttpServletRequest request, HttpServletResponse response) {
// TODO Auto-generated method stub
String uri = request.getRequestURI();
RequestDispatcher rd = null;
CAppModel model = new CAppModel();
System.out.println("Inside process ()");
try{
if(uri.contains("/Login"))
{
System.out.println("Inside Login.do");
rd = request.getRequestDispatcher("Login.jsp");
rd.forward(request,response);
}
if(uri.contains("/Register.do"))
{
System.out.println("inside Register.do");
}
if(uri.contains("/LoginBean.do"))
{
System.out.println("Inside LoginBean.do");
LoginBean lb = (LoginBean)request.getAttribute("login");
System.out.println("toString(): "+lb.toString());
String result = model.authenticate(lb);
System.out.println("CS: result of auth "+result);
if(result.equals("Success"))
{
System.out.println("Inside if Success of loginbean");
HttpSession session = request.getSession(true);
session.setAttribute("user", lb.getEmail());
rd = request.getRequestDispatcher("Menu.jsp");
rd.forward(request, response);
}
else
{
System.out.println("failed auth "+result);
request.setAttribute("errorMsg", result);
rd = request.getRequestDispatcher("Login.jsp");
rd.forward(request,response);
}
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
/**
* #see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
process(request,response);
}
}
I am getting the following error
java.lang.IllegalStateException: Cannot forward after response has been committed
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:328)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)
at com.aditya.CApp.ControllerServlet.process(ControllerServlet.java:69)
at com.aditya.CApp.ControllerServlet.doGet(ControllerServlet.java:31)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)
at org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:741)
at org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:711)
at org.apache.jsp.LoginInt_jsp._jspService(LoginInt_jsp.java:104)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:617)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1527)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1484)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
A request containing /LoginBean.do will trigger 2 if blocks causing 2 forwards to be invoked causing the error after the 2nd forward. While you could re-arrange the the if statements as
if (uri.contains("/LoginBean.do")) {
...
else if (uri.contains("/LoginBean")) {
...
Generally its simpler to use an individual servlet per if block functionality.
you must return; after a forward. otherwise the following code would executed also... in your case the conditions containing /Login and /LoginBean.do