J2EE Spring Hibernate Difference between HashMap and HashTable? Can we make hashmap synchronized?

HashMap vs Hashtable in Java
Difference between HashMap and Hashtable in Java question oftenly asked in core Java interviews to check whether candidate understand correct usage of collection classes and aware of alternative solutions available. Along with How HashMap internally works in Java and ArrayList vs Vector, this  is one of the oldest question from Collection framework in Java. Hashtable is a legacy Collection class and it's there in Java API from long time but it got refactored to implement Map interface in Java 4 and from there Hashtable became part of Java Collection framework. Hashtable vs HashMap in Java is so popular a question that it can top any list of Java Collection interview Question. You just can't afford not to prepare HashMap vs Hashtable before going to any Java programming interview. In this Java article we will not only see some important differences between HashMap and Hashtable but also some similarities between these two collection classes. Let's first see How different they are :
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