Difference between ClassNotFoundException and NoClassDefFoundError in java ?
- ClassNotFoundException and NoClassDefFoundError occur when a particular class is not found at runtime. However, they occur at different scenarios.
- ClassNotFoundException is an exception that occurs when you try to load a class at run time using Class.forName() or loadClass() methods and mentioned classes are not found in the classpath.
- NoClassDefFoundError is an error that occurs when a particular class is present at compile time, but was missing at run time.
| NoClassDefFoundError | ClassNotFoundException |
|---|---|
| NoClassDefFoundError is an error. It is the type of java.lang.Error. |
ClassNotFoundException is an exception. It is the type of java.lang.Exception. |
| It occurs when java runtime system doesn’t find a class definition, which is present at compile time, but missing at run time. |
It occurs when an application tries to load a class at run time which is not updated in the classpath. |
| It is thrown by the Java Runtime System. | It is thrown by the application itself. It is thrown by the methods like Class.forName(), loadClass() and findSystemClass(). |
| It occurs when required class definition is missing at runtime. |
It occurs when classpath is not updated wih required JAR files. |
