java lang nullpointerexception jsp

1. During Development today, we suddenly encountered the following problems. The console is printed as follows: 2010-7-20 23:35:42 org. Apache. Catalina. Core. standardwrappervalve invokeSevere: servlet. Service () for servlet JSP threw exceptionJava. Lang. nosuchmethoderror: javax. servlet. jsp. jspfactory. getjspapplicationcontext (ljavax/servlet/servletcontex

My solution is: Don't use xwork-2.1.6.jar, for xwork-2.1.2.jar! The struts tag library is introduced in the JSP page: Write a simple form, JSP error after running result: Java. Lang. classnotfoundexception: COM. opensymphony. xwork2.util. textutils Literally, we already know the cause: the textutils

The following lists the NullPointerException that often occurs when we learn java and its solutions. 1. Null Pointer Error java. lang. nullPointerException uses the Basic JAVA data type. The value of the variable is either the def

/catalina. sh Add the following lines to "echo" Using CATALINA_BASE: $ CATALINA_BASE ": JAVA_OPTS ="-server-Xms800m-Xmx800m-XX: MaxNewSize = 256 m" Java. lang. OutOfMemoryError: PermGen space Exception Handling in tomcat 1. PermGen space the full name of PermGen space is Permanent Generation space, which refers to the Permanent storage area of the memory. This memory is mainly used by JVM to store Class an

The exception of the null pointer is disgusting, I am afraid is the actual application of the most frequently occurring anomalies, the following is how to avoid nullpointerexception appearance of the technique Before using an object, it is best to know if they are possible null, and if not, use the IF statement to determine whether to use an object, or to traverse a collection, you need to make sure that they are non-empty. It's a rule that w

nullpointerexception is considered the most common mistake of Java programmers. Lang ensures that you do not make the same mistake. Nullpointerexception is not thrown even if a null value is passed to indexof () or other such methods. Indexof () will return-1 directly.In this way, only a few lines of simple code can b

Package java. Lang; Import java. Io .*;Import java. util. properties;Import java. util. propertypermission;Import java. util. stringtokenizer;Import java. Security. accesscontroller;Imp

. Examples and instructions3.1 search for all methods declared in the classImport java. Lang. Reflect .*; Public class Method1 { Private int F1 ( Object P, int X) throws nullpointerexception { If (P = NULL) Throw new nullpointerexception (); Return X; } Public static void main (string ARGs []) { Try { Class CLS = Clas

Exception Org. apache. jasper. jasperexception: javax. servlet. servletexception: Java. lang. outofmemoryerror: Java heap spaceorg. apache. jasper. servlet. jspservletwrapper. handlejspexception (jspservletwrapper. java: 505) Org. apache. jasper. servlet. jspservletwrapper. service (jspservletwrapper.

. facesservlet is not found, but I put the class package in classpath, which can be seen in "Libraries" of Eclipse. Why? Why does Tomcat go to WEB-INF/classes to find this file? It took me a whole day to solve this problem. Refer to the two articles1. http://dev.eclipse.org/mhonarc/lists/wtp-jsf-dev/msg00158.html2. http://forum.java.sun.com/thread.jspa? Forumid = 427 threadid = 598929 Step 1:Deploy the jar package in class_path to the WEB-INF directory. This is configured in the properties of t

"echo" Using CATALINA_BASE: $ CATALINA_BASE:JAVA_OPTS = "-server-Xms800m-Xmx800m-XX: MaxNewSize = 256 m" Java. lang. OutOfMemoryError: PermGen space Exception Handling in tomcat I. PermGen spacePermGen space stands for Permanent Generation space, which is the Permanent storage area of the memory,This memory is mainly used by JVM to store Class and Meta information. When the Class is loaded, it will be pl

Exception one,Java. Lang. illegalargumentexception: view not attached to Window ManagerAt Android. View. windowmanagerimpl. findviewlocked (windowmanagerimpl. Java: 664)At Android. View. windowmanagerimpl. removeview (windowmanagerimpl. Java: 354)At Android. View. windowmanagerimpl $ compatmodewrapper. removeview (wind

From: http://hi.baidu.com/cjxgotofly/blog/item/ef981434e2e112355ab5f55f.html Java. Lang. outofmemoryerrorTroubleshooting Cause:The following are common examples: 1. The amount of data loaded in the memory is too large, such as extracting too much data from the database at a time; 2. There are references to objects in the Collection class, which are not cleared after use, so that JVM cannot be

Why JAVA. Lang. unsatisfiedlinkerror: CC error occurs in the 2ee engine (11:03:29) Tags: Report software report Tool Web report software download it wishful report Category: Basic Concepts Java. Lang. unsatisfiedlinkerror is displayed on the "run JSP Report

Configure the following dependencies in Maven: Run in resin-3.0.28 and report the following error: Servlet. Service () for servlet JSP threw exceptionJava. Lang. noclassdeffounderror: javax/El/elexception The reason is that the container does not support jstl1.2, just replace it with the following dependencies: The same problem also exists in Tomcat. Tomcat6 jsp2.1/servlet2.5/jstl2.0 Tomcat5 jsp2.0/servl

Error message: Severe: servlet. Service () for servlet showbaby threw exceptionJava. Lang. illegalstateexception: cannot forward after response has been committedAt org. Apache. Catalina. Core. applicationdispatcher. doforward (applicationdispatcher. Java: 312)At org. Apache. Catalina. Core. applicationdispatcher. Forward (applicationdispatcher. Java: 302)At com.

When I did the graphic verification code, I randomly found a segment of code from the Internet. The result showed this exception. The details are as follows: ( 4361578 MS) [HTTP - 8080 - Processor25] error: org. Apache. Catalina. Core. containerbase. [Catalina]. [localhost]. [ / Xixibar]. [JSP] # invoke: servlet. Service () For Servlet JSP threw exception Java.

. classnotfoundexception ".Immediately exiting rose results in a "Java. Lang. nullpointerexception" WarningAnd the Rose does not respond. Cause: This is usually due to a broken Microsoft Java Vm, but may be due to a missingRegistry entry. Resolution: First, confirm that the Windows registry value "trustedclassp

Take the tomcat environment as an example. Other WEB servers, such as jboss and weblogic, share the same principle.1. java. lang. OutOfMemoryError: PermGen spacePermGen space stands for Permanent Generation space, which is the Permanent storage area of the memory,This memory is mainly used by JVM to store Class and Meta information. When the Class is loaded, it will be placed in PermGen space,Unlike the Hea

Package java. Lang. Reflect; Import java. Lang. Ref .*;Import java. util .*; Import sun. Misc. proxygenerator; /*** Example of using proxy*Interface TT {String getst ();} Class STT implements TT {Public String getst (){Return "lqtest ";}} Class myhandler implements invocatio