Java J2EE Spring How to resolve java.lang.ClassNotFoundException in Java

What is ClassNotFoundException in Java
ClassNotFoundException is one of Java nightmare every Java developer face in there day to day life. java.lang.NoClassDefFoundError and java.lang.ClassNotFoundException are two errors  which occurs by and now and chew up of your precious time while finding and fixing root cause. From the name java.lang.ClassNotFoundException looks quite simple but underlying cause of it is always different and which classifies it as an environmental issue. In this java tutorial we will see what is ClassNotFoundException in java, what is real cause of it and how to fix it along with some more frequent and infamous examples of java.lang.ClassNotFoundException in Java or J2EE, Don’t mistake this exception with NoClassDefFoundError in Java which is also due to incorrect classpath in Java.  Though both of them are related to missing class file when Java tries to load class in Java they are completely different to each other.  Correct understanding of  When class is loaded in Java and How Classpath works  is must to troubleshoot and fix this error quickly.
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