Read about java lang nullpointerexception jsp, The latest news, videos, and discussion topics about java lang nullpointerexception jsp from alibabacloud.com
main program running, so if your APP loads a lot of classes, the PermGen space error may occur.
Pay attention to the red part. This problem may occur if too many classes are loaded.
Exception: java. lang. OutOfMemoryError: PermGen space
Possible causes include:
Too many classes are loaded.
Too many jar files are loaded.
Too many jar files are loaded repeatedly.
JavalangOutOfMemoryError: PermGen space
Me
Severe: servlet. Service () for servlet JSP threw exceptionJava. Lang. linkageerror: loader Constraint Violation: when resolving Interface Method
"Javax. servlet. jsp. jspapplicationcontext. getexpressionfactory () ljavax/El/expressionfactory;" The Class Loader (instance
Org/Apache/Jasper/servlet/jasperloader) of the current class, org/Apache/
as the following information:
Java. Lang. illegalargumentexception: ID to load is required for loadingOrg. hibernate. event. loadevent. Org. hibernate. event. loadevent. Org. hibernate. impl. sessionimpl. Get (sessionimpl. Java: 812)Org. hibernate. impl. sessionimpl. Get (sessionimpl. Java: 808)Com. zyeeda. projs. cm
Tomcat outofmemoryerror (permgen space) Solution
Recently I have been familiar with a project that has been developed for several years. I need to port the database from MySQL to Oracle. First, I need to point the JDBC connection to MySQL and package it into tomcat to run it. There is no problem, however, when the JDBC connection is directed to Oracle, Tomcat continuously throws Java. lang. outofmemoryerro
Java. lang. OutOfMemoryError: PermGen space and Its Solution,
Recently, an airport project reported an error on the tomcat terminal. Check the log and find that "java. lang. OutOfMemoryError: PermGen space" causes service impact.
The centos 6.5 System
Java 1.7-79
Tomcat a
, such as JBoss and WebLogic, share the same principle.
I. java. lang. outofmemoryerror: 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 and meta information, when a class is loaded, it will be placed in the permgen space. It is different from the heap region where the class instance is s
When uploading, downloading, or filtering files, we may need to use the output stream of the page.
For example, in JSP:
Response. Reset ();
Response. setcontenttype ("application/vnd. MS-excel ");
Outputstream OS = response. getoutputstream ();
Throw an exception:
Error [engine] standardwrappervalve [JSP]: servlet. Service () for servlet JSP threw exception
Javax. servlet. ServletException: java. lang. NoClassDefFoundError: javax/el/ELResolver error solution,
Today, you don't need eclipse, myeclipse, or other development tools. When writing a JSP page (a little dead), you suddenly encounter problems that you have never encountered before. The error is as follows:
HTTP Status 500 - java.lang.NoClassDefFoundError: jav
Solving Tomcat outofmemoryerror: heap space and permgen spacetomcat March 12th, 2009
It's quite common to run inMemory problemsWhen running some big Java EE application on a Tomcat server.Some of the most commmon errors are like the following ones.
This is about a fullHeap Space:
Severe: servlet. Service () for servlet JSP threw exceptionjava. Lang. outofmem
Package java. Lang;Import java. Io .*;
/**** Throwable is the parent class of all errors and exceptiong.* Note that there are four constructors:* Throwable ()* Throwable (string message)* Throwable (throwable cause)* Throwable (string message, throwable cause)** Comment by liqiang**/Public class throwable implements serializable {Private Static final long serialv
as jboss and weblogic, share the same principle.I. java. lang. outOfMemoryError: 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 and Meta information, when a Class is loaded, it will be placed in the PermGen space. It is different from the Heap region where the Class Instance is stored.
JSP labels have never been used before. Now, after adding JSP labels to the project, a problem occurs:
Org. Apache. Jasper. jasperexception: Java. Lang. illegalargumentexception: attribute type = "password" is not allowed
This error is introduced in JSP Label
Use
Error description:
Today, when a session bean is called Using JSP, a "Java. Lang. classcastexception: $ proxy65" error occurs. Baidu has explained the following in Chinese:
The default Web Loader of JBoss is false. According to the description in the configuration file, the purpose is to display multiple loaders, determine whether to use the JBoss Web Loader as a
Java basics-JSP (2), java basics jsp
1. JSP implicit object Overview
To simplify the compilation of jsp expressions and script snippet code, JSP provides a total of nine pre-defined var
annotations cannot prevent JSP or Java code execution.
JSP Directive)Page commandInclude commandTaglib command
Syntax:
The page command defines the global attributes of JSP files. 1. The language can only be java2. After extends JSP is translated, the Servlet inherits the
Notes for Java and JSP Programming
1. when the println () method is used for objects of the string type, if the object is null, null is printed instead of nullpointerexception, which may lead to the illusion of reference, subsequent operations on strings may cause problems.
2. nullpointerexception is thrown because the
ways:Javax. servlet. http. httpsession. getservletcontext ()Javax. servlet. jsp. pagecontext. getservletcontext ()Javax. servlet. servletconfig. getservletcontext ())
4. Methods for obtaining relative paths and absolute paths in Java class4.1 obtain the absolute path in a separate Java classAccording to the java. Io.
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.