Difference between forward and Redirect
forward Control can be forward to resources available within the server from where the call is made. This transfer of control is done by the container internally and browser / client is not involved....
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What is the difference between Difference between doGet() and doPost()?
A doGet() method is limited with 2k of data to be sent, and doPost() method doesn’t have this limitation. A request string for doGet() looks like the following: http://www.javaskool.com/servlet123?p1=v1&p2=v2&…&pN=vN doPost() method call doesn’t need...
What is preinitialization of a servlet?
A container does not initialize the servlets ass soon as it starts up, it initializes a servlet when it receives a request for that servlet first time. This is called lazy loading. The servlet...
What is ServletContext?
ServletContext interface is a window for a servlet to view it’s environment. A servlet can use this interface to get information such as initialization parameters for the web applicationor servlet container’s version. Every web...
The EJB container implements the EJBHome and EJBObject classes.
The EJB container implements the EJBHome and EJBObject classes. For every request from a unique client, does the container create a separate instance of the generated EJBHome and EJBObject classes? The EJB container maintains...
What is EJB QL?
EJB QL is a Query Language provided for navigation across a network of enterprise beans and dependent objects defined by means of container managed persistence. EJB QL is introduced in the EJB 2.0 specification....
What is the advantage of using Entity bean for database operations, over directly using JDBC API to do database operations? When would I use one over the other?
Entity Beans actually represents the data in a database. It is not that Entity Beans replaces JDBC API. There are two types of Entity Beans Container Managed and Bean Mananged. In Container Managed Entity...
Can you control when passivation occurs?
The developer, according to the specification, cannot directly control when passivation occurs. Although for Stateful Session Beans, the container cannot passivate an instance that is inside a transaction. So using transactions can be a...
Can the primary key in the entity bean be a Java primitive type such as int?
The primary key can’t be a primitive type–use the primitive wrapper classes, instead. For example, you can use java.lang.Integer as the primary key class, but not int (it has to be a class, not...
How EJB Invocation happens?
Step 1: Retrieve Home Object reference from Naming Service via JNDI. step 2: Return Home Object reference to the client. step 3: Create me a new EJB Object through Home Object interface. step 4:...
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