[Java] convert String to Int

[cyclone9]

hi guys

if(Integer.parseInt(m_sSortType) == 1)

{

if(Integer.parseInt(m_sSortOrder) == 1))

else

}

else

am i using Integer.parseInt(m_sSortType) a right method to convert them... i have error

[_kane81]

Looks right, lookup Integer in the Java API. what type is msSortType?

what error message are you getting?

[John Veteran]

  _kane81 said:

what type is msSortType?

It's a type of Hungarian notation. The m means its a member variable (member of a class) and the s means it's a variable of type string.

[masterren]

Maybe try converting the Integer object to an int. Then compare it to 1.

[_kane81]

could be the string has a space or extra characters possible not visible.

try triming the msSortType and the parsing

[cyclone9]

the error i got is as below:

HTTP Status 500 -

--------------------------------------------------------------------------------

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: null

at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:254)

at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)

at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)

at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2417)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)

at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)

at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:193)

at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:309)

at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:387)

at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:673)

at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:615)

at org.apache.jk.common.SocketConnection.runIt(ChannelSocket.java:786)

at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:666)

at java.lang.Thread.run(Thread.java:534)

root cause

java.lang.NumberFormatException: null

at java.lang.Integer.parseInt(Integer.java:436)

at java.lang.Integer.parseInt(Integer.java:518)

at org.apache.jsp.rpt_traffic_jsp._jspService(rpt_traffic_jsp.java:637)

at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:137)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)

at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:210)

at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)

at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)

at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2417)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)

at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)

at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:193)

at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:309)

at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:387)

at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:673)

at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:615)

at org.apache.jk.common.SocketConnection.runIt(ChannelSocket.java:786)

at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:666)

at java.lang.Thread.run(Thread.java:534)

*p/s: the m_sSortType i declare as string

--------------------------------------------------------------------------------

Apache Tomcat/4.1.29

[Jebadiah]

Use a try-catch block and print the exception on the screen. Also, check if the String actually contains an Integer. The root cause which you posted shows a java.lang.NumberFormatException. If you can do a debug (like in ASP.net) that would be great.

[_kane81]

your problem is your variable "msSortType" is null!

so in other words msSortType = null;

null can not be parsed you need to init msSortType to some value. sounds like you have a bug when setting msSortType

[cyclone9]

is there other method to c onvert string to integer?

it doesnt seems working...

i means some string cant be converted to integer which trigger this error

[Jebadiah]

  cyclone9 said:

is there other method to c onvert string to integer?

it doesnt seems working...

i means some string cant be converted to integer which trigger this error

I'd suggest debugging it. Either by using a debugger or by using simple System.out.println(m_sSortType). You need to see if m_sSortType contains an Integer or not. Your code for converting String to Integer is correct, but it seems there's a bug, which means m_sSortType doesn't contain an Integer in String format when you are calling the Integer.parseInt() method.

I don't think there is any other in-built method for converting a String to Integer. You will have to make one yourself if you are so sure that Java is at fault. :rolleyes:

[_kane81]

^^

I told you your code is right for parsing a string, your problem is you string is NULL!!!!!!! no value has been set for the string. your problem is logical and not syntax!

[kjordan2001]

Throw your conversion in a try-catch block.

try {

int value = Integer.parseInt(m_sSortType);

/*Do something with value*/

} catch (NumberFormatException e) /*Whoops, we had an error in conversion*/

{ e.printStackTrace(); }

[AaronMT]

Shouldnt the problem just be instead of using == use Equals(); ?

[kjordan2001]

  INFERNO2k said:

Shouldnt the problem just be instead of using == use Equals(); ?

If we were comparing two Integers (objects/wrappers for ints) instead of two ints (primitives), then yes, but we're not since parseInt returns an int (primitive).