Sr.Java Web Developer

It will generate HTTP GET request

Stuff like Encryption, Authentication and Authorization

☛ 1) The URL being sent is wrong

☛ 2) The web.xml mapping is wrong

☛ 3) The web server is down

☛ 4) The application has not been deployed

The following code explain how to delete a Cookie in a JSP :

Cookie mycook = new Cookie("name1","value1");

response.addCookie(mycook1);

Cookie killmycook = new Cookie("mycook1","value1");

killmycook . set MaxAge ( 0 );

killmycook . set Path ("/");

killmycook . addCookie ( killmycook 1 );

This method returns the message String about the exception . The message can be provided through its constructor.

☛ Registering the driver class

☛ Creating connection

☛ Creating statement

☛ Executing queries

☛ Closing connection

Wikipedia defines the Spring framework as “an application framework and inversion of control container for the Java platform. The framework’s core features can be used by any Java application, but there are extensions for building web applications on top of the Java EE platform.” Spring is essentially a lightweight, integrated framework that can be used for developing enterprise applications in java.

☛ DispatcherServlet is basically the front controller in the Spring MVC application as it loads the spring bean configuration file and initializes all the beans that have been configured. If annotations are enabled, it also scans the packages to configure any bean annotated with @Component, @Controller, @Repository or @Service annotations.

☛ ContextLoaderListener, on the other hand, is the listener to start up and shut down the WebApplicationContext in Spring root. Some of its important functions includes tying up the lifecycle of Application Context to the lifecycle of the ServletContext and automating the creation of ApplicationContext.

We don’t need to configure JSP standard tags in web.xml because when container loads the web application and find TLD files, it automatically configures them to be used directly in the application JSP pages. We just need to include it in the JSP page using taglib directive.

In case you are facing any challenges with these java interview questions, please comment your problems in the section below. Apart from this Java Interview Questions Blog.

Synchronization refers to multi-threading. A synchronized block of code can be executed by only one thread at a time. As Java supports execution of multiple threads, two or more threads may access the same fields or objects. Synchronization is a process which keeps all concurrent threads in execution to be in sync. Synchronization avoids memory consistency errors caused due to inconsistent view of shared memory. When a method is declared as synchronized the thread holds the monitor for that method’s object. If another thread is executing the synchronized method the thread is blocked until that thread releases the monitor.

Perform the Root Cause Analysis and make sure the changes done have not effected any other module.

The DatabaseMetaData interface returns the information of the database such as username, driver name, driver version, number of tables, number of views etc.

JSP is a technology on the server’s side to make content generation simple. They are document centric, whereas servlets are programs. A Java server page can contain fragments of Java program, which execute and instantiate Java classes. However, they occur inside HTML template file. It provides the framework for development of a Web Application.

The Connection interface maintains a session with the database. It can be used for transaction management. It provides factory methods that returns the instance of Statement, PreparedStatement, CallableStatement and DatabaseMetaData.

This method returns an array containing each element on the stack trace. The element at index 0 represents the top of the call stack whereas the last element in the array represents the method at the bottom of the call stack.

Batch processing helps you to group related SQL statements into a batch and execute them instead of executing a single query. By using batch processing technique in JDBC, you can execute multiple queries which makes the performance faster.

Jquery and DOJO are java script frameworks for writing rich web applications but AJAX is a server communication mechanism which can issue requests without page reload.

Core Java is something that provides the API's like regular expression, String handling, collections. But enterprise java involves writing scalable, secure and per-formant applications which can have large user base.

Statement executeQuery(String query) is used to execute Select queries and returns the ResultSet. ResultSet returned is never null even if there are no records matching the query. When executing select queries we should use executeQuery method so that if someone tries to execute insert/update statement it will throw java.sql.SQLException with message “executeQuery method can not be used for update”.

The DriverManager class manages the registered drivers. It can be used to register and unregister drivers. It provides factory method that returns the instance of Connection.