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Normally we write classes with private variables and expose getters and setters to those variables which we think right approach . this is called as encapsulation in java . to protect our class properties we define those variables as private and expose public methods to modify properties . but there encapsulation not providing any security as such .      take a look at below class which has public members and we can change those members directly without using methods . even child class can access those variables modify directly .     public class Employee {       public String firstName;      public String lastName;   } but here only the problem is we can't test these classes and also latest frameworks like spring ,struts developed on POJO definition , hence if you don't expose methods difficult to use these type of classes .           Drawbacks     ...

Spring Declarative Txn Management current transaction propagation points as mentioned below S.N. Propagation & Description 1 TransactionDefinition.PROPAGATION_MANDATORY Support a current transaction; throw an exception if no current transaction exists. 2 TransactionDefinition.PROPAGATION_NESTED  Execute within a nested transaction if a current transaction exists. 3 TransactionDefinition.PROPAGATION_NEVER  Do not support a current transaction; throw an exception if a current transaction exists. 4 TransactionDefinition.PROPAGATION_NOT_SUPPORTED  Do not support a current transaction; rather always execute non-transactionally. 5 TransactionDefinition.PROPAGATION_REQUIRED   Support a current transaction; create a new one if none exists. 6 TransactionDefinition.PROPAGATION_REQUIRES_NEW   Create a new transaction, suspending the current transaction if one exists. 7 TransactionDefinition.PROPAGATION_SUPPORTS   Support a current transacti...

Friends,            you might be wondering why struts 2 framework came into picture , there are few reasons which I would like to explain . Anyways I have given well formatted table with differences below .     Struts 1 Actions are classes and Singletons , so there will be one object which handles the request hence this is bit trade off and prone to bugs . we need to make sure that our resources in presentation layer which calls DAO layer should be protected i.e should be thread safe .       Anyways looks at below tabular form which explains clearly about the differences       Struts 1 vs Struts 2 Feature  Struts 1  Struts 2  Action classes  Struts 1 requires Action classes to extend an abstract base class. A common problem in Struts 1 is programming to abstract classes instead of interfaces.  An Struts 2 Action  may  implement an  Action  interfac...