java.text.ParseException: Unparseable date: ""

[JayaSiji Gopal]

I have a text field in the jsp page. This field is supposed to have input of a date in the format MM/dd/YYYY

If the user does not input any date, i get the following exception:

  
 
java.text.ParseException: Unparseable date: ""
        at java.text.DateFormat.parse(DateFormat.java:335)
        at com.gs.fw.sox404.emailutility.util.impl.TemplateUtil.parseDate(TemplateUtil.java:138)
        at com.gs.fw.sox404.emailutility.util.impl.TemplateUtil.fillFormData(TemplateUtil.java:102)
        at com.gs.fw.sox404.emailutility.servlet.EmailProfileServlet.doPost(EmailProfileServlet.java:102)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
        at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
        at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
 
In my java class, i have put the following condition:
value = date value from the jsp page.
 
if(value != null || !value.equalsIgnoreCase("")) { 
logger.debug("in if");
dto.setEventDate(parseDate(value));
} else { 
logger.debug("in else");
dto.setEventDate(null);
}
 

I see that when there is no date entered, the condition in the if loop is satisified and the exception is thrown. what am i missing here?

[Jyothish Divakar]

I think it will get corrected if you give

if(value != null && !value.equalsIgnoreCase("")) {

since it was OR it will check for not null (!= null) and will enter the loop once is satisfied even if it is empty string ("") since it will not check for the second expression if it gets a true for the first expression. Also to stress a point it will be good to use constants first to avoid any null pointer exception in equalsIgnoreCase() like
!("".equalsIgnoreCase(value))

[Qussay Najjar]

Hi JayaSiji,
In such cases the best way is using JavaScript and don't even let it go to process if the values are not as you want them.
check this thread:
JavaScript Example - Check Date Formation

[Rob Spoor]

Originally posted by Qussay Najjar:
Hi JayaSiji,
In such cases the best way is using JavaScript and don't even let it go to process if the values are not as you want them.
check this thread:
JavaScript Example - Check Date Formation

Relying on Javascript alone is a very very bad idea, simply because the user can turn it off.

[Qussay Najjar]

Originally posted by Rob Prime:

Relying on Javascript alone is a very very bad idea, simply because the user can turn it off.

Yes, you're completely right, I've almost forgot.
So JavaScript can be the first line to check, and in the servlet you can use
something like this:

    String date = request.getParameter("date");
    Pattern datePattern = Pattern.compile("date: (\\d{2})/(\\d{2})/(\\d{4})");//pattern with the form dd/mm/yyyy
    Matcher dateMatcher = datePattern.matcher(date);
    if (dateMatcher.find())
    {
    String day =  dateMatcher.group(1));
      String month =  dateMatcher.group(2));
      String year = dateMatcher.group(3));
    }

Hope it helps..

[Qussay Najjar]

Originally posted by Qussay Najjar:

    Pattern datePattern = Pattern.compile("date: (\\d{2})/(\\d{2})/(\\d{4})");//pattern with the form dd/mm/yyyy

It should be:
Pattern datePattern = Pattern.compile("(\\d{2})/(\\d{2})/(\\d{4})");//pattern with the form dd/mm/yyyy