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MySql Driver Class Autoloading

Configuration
jdk version : 1.8.0_60-b27
project : maven jsp project
Mysql connector : mysql-connector-java-5.1.38 (Copied to Tomcat's lib)
Pom.xml
<!--MySql Connector/J Dependency-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
<scope>provided</scope>
</dependency>
Code Causing Error :
try(Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/myDatabase","root","")){
connection=con;
} catch (SQLException e) {
e.printStackTrace();
return null;
}
Error log
java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/myDatabase
at java.sql.DriverManager.getConnection(DriverManager.java:689)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at util.DBConnectivity.getDBConnection(DBConnectivity.java:16)
at controller.MyController.doGet(MyController.java:25)
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: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$AbstractConnectionHandler.process(AbstractProtocol.java:673)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2503)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2492)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$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 tried both of the scopes [provided and compile] in pom.xml but no change in the output!!!
Tried hundred times but can't figure out why project is not able to find the driver????

What you need to do is just these two steps, and not more:
Include your dependency properly:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>
Notice that scope is not configures, so by default it will be compile, which will make it available at runtime too.
The combination of manually copying this file to WEB-INF\lib then redeploy with scope=provided will not work because the folder will get recreated. In case you would like to make this jar available only at runtime, you need to place it to Tomcat\lib.
You need to manually load the driver before you attempt to connect anywhere. Make sure you do this before using DriverManager.
Class.forName("com.mysql.jdbc.Driver");

you are not getting the connection from a datasource hence you are not using the mysql driver in the tomcat lib.
Using DriverManager you need to load the jdbc library yourself using Class.forName("com.mysql.jdbc.Driver").newInstance(); and by removing the provided entry for it in the pom.xml or... use a datasource :)

java.lang.ClassNotFoundException while uploading an encrypted PDF file

I am getting the following exception when I am trying to upload a password protected PDF file in my application:
How to solve this problem? I tried different itext versions but still the same error. Is there anyway I can solve this issue? Thanks.
java.lang.ClassNotFoundException: org.bouncycastle.asn1.DEREncodable
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1358)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
at com.itextpdf.text.pdf.PdfEncryption.<init>(PdfEncryption.java:138)
at com.itextpdf.text.pdf.PdfReader.readDecryptedDocObj(PdfReader.java:762)
at com.itextpdf.text.pdf.PdfReader.readDocObj(PdfReader.java:1133)
at com.itextpdf.text.pdf.PdfReader.readPdf(PdfReader.java:511)
at com.itextpdf.text.pdf.PdfReader.<init>(PdfReader.java:171)
at com.itextpdf.text.pdf.PdfReader.<init>(PdfReader.java:160)
at com.quepio.web.controller.TutoContentController.processChapterContent(TutoContentController.java:2582)
at com.quepio.web.controller.TutoContentController.saveOrUpdateContent(TutoContentController.java:1694)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:933)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:867)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:855)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.quepio.web.TwoFactorAuthenticationFilter.doFilterInternal(TwoFactorAuthenticationFilter.java:54)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.quepio.web.FirstLoginFilter.doFilterInternal(FirstLoginFilter.java:108)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
I am using the following jars.
itext: 5.3.2
bcprov-jdk15on: 1.47
bcmail-jdk15on: 1.47

You have to look at the POM file that ships with iText: pom.xml
You'll discover that the current version of iText is 5.5.7:
<artifactId>itextpdf</artifactId>
<packaging>jar</packaging>
<name>iText, a Free Java-PDF library</name>
<version>5.5.7</version>
<description>iText, a free Java-PDF library</description>
Now scroll down to the dependencies and look for BouncyCastle:
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk15on</artifactId>
<version>1.49</version>
<type>jar</type>
<scope>compile</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcpkix-jdk15on</artifactId>
<version>1.49</version>
<type>jar</type>
<scope>compile</scope>
<optional>true</optional>
</dependency>
As you can see, the BC version that works with 5.5.7 is BC 1.49.
The POM files are provided, so that developers don't have to resort to "trial and error." If you are familiar with Maven, just use the POM file and you don't have to worry about which BouncyCastle version to use. All the dependencies will be downloaded automatically through Maven.
Of course: you have to make sure that BC is also available in the CLASSPATH of your server. You also need to take special care to make sure that you have only one version of BouncyCastle. A ClassNotFoundException doesn't always mean that the class isn't present. It can also mean that there's an ambiguity. If you have a class named DEREncodable in one version of BC that is in your CLASSPATH and a class with the same name in another version of BC that is in your class path, the JVM won't know which class to use and will also throw a ClassNotFoundException.

org.apache.jasper.JasperException: Unable to compile class for JSP encountered when using spring

I am new to spring. I am trying to use spring mvc to build a small web.
When I start the project, I get:
org.apache.jasper.JasperException: Unable to compile class for JSP:
An error occurred at line: 22 in the generated java file
The method getJspApplicationContext(ServletContext) is undefined for the type JspFactory
Stacktrace:
at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:92)
at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330)
at org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:439)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:349)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:327)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:314)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:589)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:662)
Http status is 500, but my index.jsp just have
<html>
<body>
<h2>Hello World!</h2>
</body>
</html>
In the web.xml:
<servlet>
<servlet-name>action</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>/jsp/index.jsp</welcome-file>
</welcome-file-list>
the action-servlet.xml:
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>
<context:component-scan base-package="com.test.Controller"/>
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix"><value>/jsp/</value></property>
<property name="suffix"><value>.jsp</value></property>
</bean>
I put index.jsp under src/main/webapp/jsp/ folder.
Could anyone please give me some hint about this problem and the problems in my xml files.I am new to spring, so lot's of confusion.
Thank you very much!

It looks there's some version mismatch. Make sure servlet-api and jsp-api are not included in your WEB-INF/lib folder
If using Maven, you must set these dependencies to <scope>provided</scope> so that they are not included in the artifact (target/foo.war)
If using eclipse, you should install another plugin - m2e-wtp, which takes care of <provided> scope dependencies (m2e doesn't do it when synchronizing with WTP)

I got the same issue because I used
- jdk1.7.0_45
- apache-tomcat-8.0.18
But after I change the server to
- apache-tomcat-7.0.57
It was fixed.

javax.faces.application.ViewExpiredException seemingly ignored

I've put the following into my web.xml:
<error-page>
<exception-type>javax.faces.application.ViewExpiredException</exception-type>
<location>/expiredIndex.jsf</location>
</error-page>
<error-page>
<exception-type>java.lang.Throwable</exception-type>
<location>/error.jsf</location>
</error-page>
<session-config>
<session-timeout>1</session-timeout>
</session-config>
When I start my app, and wait for 1 minute, if I then attempt to interact with it (JSF 1.2, h:commandButton) I get the error
SEVERE: Servlet.service() for servlet Faces Servlet threw exception
javax.faces.application.ViewExpiredException: viewId:/index.jsf - View /index.jsf could not be restored.
at com.sun.faces.lifecycle.RestoreViewPhase.execute(RestoreViewPhase.java:185)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:103)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:265)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388)
at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
Can someone tell me why it is the javax.faces.application.ViewExpiredException is not being picked up? I'm looking for the most basic expiry setup possible and surely that's all that is necessary in the web descriptor.
Thanks
EDIT
I now have in my web.xml the following:
<filter>
<filter-name>Error</filter-name>
<filter-class>myClient.ErrorFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>Error</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<error-page>
<exception-type>javax.servlet.ViewExpiredException</exception-type>
<location>/expiredIndex.jsf</location>
</error-page>
(these entries are the last filter entries in the web.xml) and a new filter with the doFilter method as described in this post. What should be happening now is the rootCause should unwrap the ViewExpiredException which should thus redirect the user to my expiredIndex page when the servlet session times out. Instead I get a 500. I can't see what else to I need to do the correct redirect in this situation. Help!
EDIT 2
Error from the 500 is:
javax.faces.application.ViewExpiredException: viewId:/index.jsf - View /index.jsf could not be restored.
com.sun.faces.lifecycle.RestoreViewPhase.execute(RestoreViewPhase.java:185)
com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:103)
com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:265)
org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388)
org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515)
prismClient.ErrorFilter.doFilter(Unknown Source)
which I guess is the standard one.

This is because the ViewExpiredException -as every other FacesException- is under the covers been wrapped in a ServletException. This one is been used to find matches in the declared error pages. The closest match is java.lang.Throwable and thus the associated error page is been shown.
If no match would have been found, then the root cause of the ServletException would have been unwrapped and a second pass through the declared error pages will be made with the unwrapped exception. If you remove the java.lang.Throwable entry, you'll see that this will work.
If you want to keep the java.lang.Throwable, then best what you can do is to create a Filter which unwraps any FacesException from the ServletException and rethrows it.
See also:
Issue with JSF ViewExpiredException and multiple error page definitions

Please see the blog posted on similar issue here: it's less cumbersome and quite effective. Be sure to include your "view-handler" tags within the "application" tags, doing this worked for me, cheers.

Why did Servlet.service() for servlet jsp throw this exception?

I get the following error, what could be the problem?
My context descriptor:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<servlet>
<servlet-name>UploadServlet</servlet-name>
<servlet-class>controller.UploadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>UploadServlet</servlet-name>
<url-pattern>/UploadServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.index_jsp._jspInit(index_jsp.java:22)
at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:52)
at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:159)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:329)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Unknown Source)
Feb 23, 2010 11:35:28 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.index_jsp._jspInit(index_jsp.java:22)
at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:52)
at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:159)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:329)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Unknown Source)

It can be caused by a classpath contamination. Check that you /WEB-INF/lib doesn't contain something like jsp-api-*.jar.

If your project is Maven-based, remember to set scope to provided for such dependencies as servlet-api, jsp-api. Otherwise, these jars will be exported to WEB-INF/lib and hence contaminate with those in Tomcat server. That causes painful problems.
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.1</version>
<scope>provided</scope>
</dependency>

I had this error; it happened somewhat spontaneously, and the page would halt in the browser in the middle of an HTML tag (not a section of code). It was baffling!
Turns out, I let a variable go out of scope and the garbage collector swept it away and then I tried to use it. Thus the seemingly-random timing.
To give a more concrete example... Inside a method, I had something like:
Foo[] foos = new Foo[20];
// fill up the "foos" array...
return Arrays.asList(foos); // this returns type List<Foo>
Now in my JSP page, I called that method and used the List object returned by it. The List object is backed by that "foos" array; but, the array went out of scope when I returned from the method (since it is a local variable). So shortly after returning, the garbage collector swept away the "foos" array, and my access to the List caused a NullPointerException since its underlying array was now wiped away.
I actually wondered, as I wrote the above method, whether that would happen.
The even deeper underlying problem was premature optimization. I wanted a list, but I knew I would have exactly 20 elements, so I figured I'd try to be more efficient than new ArrayList<Foo>(20) which only sets an initial size of 20 but can possibly be less efficient than the method I used. So of course, to fix it, I just created my ArrayList, filled it up, and returned it. No more strange error.

The problem is in your JSP, most likely you are calling a method on an object that is null at runtime.
It is happening in the _jspInit() call, which is a little more unusual... the problem code is probably a method declaration like <%! %>
Update: I've only reproduced this by overriding the _jspInit() method. Is that what you're doing? If so, it's not recommended - that's why it starts with an _.

I tried my best to follow the answers given above. But I have below reason for the same.
Note: This is for maven+eclipse+tomcat deployment and issue faced especially with spring mvc.
1- If you are including servlet and jsp dependency please mark them provided in scope.
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>javax.servlet.jsp-api</artifactId>
<version>2.3.1</version>
<scope>provided</scope>
</dependency>
Possibly you might be including jstl as dependency. So, jsp-api.jar and servlet-api.jar will be included along. So, require to exclude the servlet-api and jsp-api being deployed as required lib in target or in "WEB-INF/lib" as given below.
<dependency>
<groupId>javax.servlet.jsp.jstl</groupId>
<artifactId>jstl-api</artifactId>
<version>1.2</version>
<exclusions>
<exclusion>
<artifactId>servlet-api</artifactId>
<groupId>javax.servlet</groupId>
</exclusion>
<exclusion>
<artifactId>jsp-api</artifactId>
<groupId>javax.servlet.jsp</groupId>
</exclusion>
</exclusions>
</dependency>