Why am I getting a NoClassDefFoundError in Java?

Why am I getting a NoClassDefFoundError in Java?

Just like ClassNotFoundException, NoClassDefFoundError occurs at runtime. We get this error when the class is not available in the program at runtime. In this case, the class was successfully compiled by the compiler, and when we try to run the program, the class will not be available. …

How do I activate a jar file?

jar, follow these rules:

  1. Open a notepad.exe.
  2. Write : java -jar Example. jar.
  3. Save it with the extension . bat.
  4. Copy it to the directory which has the . jar file.
  5. Double click it to run your . jar file.

How do you handle if you get Noclassfoundexception?

How to Resolve ClassNotFoundException in Java

  1. Find out which JAR file contains the problematic Java class.
  2. Check whether this JAR is present in the application classpath.
  3. If that JAR is already present in the classpath, make sure the classpath is not overridden (e.g. by a start-up script).

What is difference between Classnotfound and Noclassdefined exception?

ClassNotFoundException is an exception that occurs when you try to load a class at run time using Class. NoClassDefFoundError is an error that occurs when a particular class is present at compile time, but was missing at run time.

How do I stop NoClassDefFoundError in Java?

NoClassDefFoundError means that the class is present in the classpath at Compile time , but it doesn’t exist in the classpath at Runtime . If you’re using Eclipse, make sure you have the shapes , linepoints and the spaceobjects as entries in the . classpath file.

How do I run a Java program from a JAR file?

To run an application in a non-executable JAR file, we have to use -cp option instead of -jar. We’ll use the -cp option (short for classpath) to specify the JAR file that contains the class file we want to execute: java -cp jar-file-name main-class-name [args …]

Why am I getting NoClassDefFoundError in Java?

The first problem case we will cover is related to a Java program packaging and / or classpath problem. A typical Java program can include one or many JAR files created at compile time. NoClassDefFoundError can often be observed when you forget to add JAR file (s) containing Java classes referenced by your Java or Java EE application.

How do I load a JAR file into a class path?

To load classes in JAR files within a JAR file into the class path, you must write custom code to load those classes. For example, if MyJar.jar contains another JAR file called MyUtils.jar, you cannot use the Class-Path header in MyJar.jar’s manifest to load classes in MyUtils.jar into the class path.

Could not find or load main class in Java?

1 @Vikram the “could not find or load main class” is not a Java exception, it is caused by the launcher (which inspects the JAR and the main manifest attribute). – eckes Jan 15 ’15 at 21:38 3 ClassNotFoundException is also thrown when a class has static initialization that throws an error or exception.

Is it possible to run a class within a jar?

James Boswell wrote: What you are trying to achieve is not currently possible i.e. trying to run a class within a jar which requires jar files also contained with the same jar – see http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4648386. Thanks, is this still an issue with 1.6.