NetSuite Most Frequently Asked Latest Advanced Java Interview Questions Answers
What Is The Design Role Played By Struts?
The role played by Structs is controller in Model/View/Controller(MVC) style. The View is played by JSP and Model is played by JDBC or generic data source classes. The Struts controller is a set of programmable components that allow developers to define exactly how the application interacts with the user.
How Struts Control Data Flow?
Struts implements the MVC/Layers pattern through the use of ActionForwards and ActionMappings to keep control-flow decisions out of presentation layer.
What Configuration Files Are Used In Struts?
ApplicationResources.properties
struts-config.xml
These two files are used to bridge the gap between the Controller and the Model.
What Helpers In The Form Of Jsp Pages Are Provided In Struts Framework?
--struts-html.tld
--struts-bean.tld
--struts-logic.tld
Is Struts Efficient?
The Struts is not only thread-safe but thread-dependent(instantiates each Action once and allows other requests to be threaded through the original object.
ActionForm beans minimize subclass code and shorten subclass hierarchies.
The Struts tag libraries provide general-purpose functionality.
The Struts components are reusable by the application.
The Struts localization strategies reduce the need for redundant JSPs.
The Struts is designed with an open architecture--subclass available.
The Struts is lightweight (5 core packages, 5 tag libraries).
The Struts is open source and well documented (code to be examined easily).
The Struts is model neutral.
How You Will Enable Front-end Validation Based On The Xml In Validation.xml?
The < html:javascript > tag to allow front-end validation based on the xml in validation.xml. For example the code: < html:javascript formName=logonForm dynamicJavascript=true staticJavascript=true / > generates the client side java script for the form logonForm as defined in the validation.xml file. The < html:javascript > when added in the jsp file generates the client site validation script.
What Is Actionservlet?
The class org.apache.struts.action.ActionServlet is the called the ActionServlet. In the the Jakarta Struts Framework this class plays the role of controller. All the requests to the server goes through the controller. Controller is responsible for handling all the requests.
How You Will Make Available Any Message Resources Definitions File To The Struts Framework Environment?
Message Resources Definitions file are simple .properties files and these files contains the messages that can be used in the struts project. Message Resources Definitions files can be added to the struts-config.xml file through < message-resources / > tag. Example: < message-resources parameter= MessageResources / >
What Is Action Class?
The Action Class is part of the Model and is a wrapper around the business logic. The purpose of Action Class is to translate the HttpServletRequest to the business logic. To use the Action, we need to Subclass and overwrite the execute() method. In the Action Class all the database/business processing are done. It is advisable to perform all the database related stuffs in the Action Class. The ActionServlet (commad) passes the parameterized class to Action Form using the execute() method. The return type of the execute method is ActionForward which is used by the Struts Framework to forward the request to the file as per the value of the returned ActionForward object.
Write Code Of Any Action Class?
Here is the code of Action Class that returns the ActionForward object.
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
public class TestAction extends Action
{
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) throws Exception
{
return mapping.findForward(\"testAction\");
}
}
What Is Actionform?
An ActionForm is a JavaBean that extends org.apache.struts.action.ActionForm. ActionForm maintains the session state for web application and the ActionForm object is automatically populated on the server side with data entered from a form on the client side.
What Is Struts Validator Framework?
Struts Framework provides the functionality to validate the form data. It can be use to validate the data on the users browser as well as on the server side. Struts Framework emits the java scripts and it can be used validate the form data on the client browser. Server side validation of form can be accomplished by sub classing your From Bean with DynaValidatorForm class. The Validator framework was developed by David Winterfeldt as third-party add-on to Struts. Now the Validator framework is a part of Jakarta Commons project and it can be used with or without Struts. The Validator framework comes integrated with the Struts Framework and can be used without doing any extra settings.
Give The Details Of Xml Files Used In Validator Framework?
The Validator Framework uses two XML configuration files validator-rules.xml and validation.xml. The validator-rules.xml defines the standard validation routines, these are reusable and used in validation.xml. to define the form specific validations. The validation.xml defines the validations applied to a form bean. How you will display validation fail errors on jsp page? - The following tag displays all the errors: < html:errors/ >
Why Do We Need Struts?
Java technologies give developers a serious boost when creating and maintaining applications to meet the demands of today's public Web sites and enterprise intranets. Struts combines Java Servlets, Java ServerPages, custom tags, and message resources into a unified framework. The end result is a cooperative, synergistic platform, suitable for development teams, independent developers, and everyone in between.
How Does Struts Work?
Java Servlets are designed to handle requests made by Web browsers. Java ServerPages are designed to create dynamic Web pages that can turn billboard sites into live applications. Struts uses a special Servlet as a switchboard to route requests from Web browsers to the appropriate ServerPage. This makes Web applications much easier to design, create, and maintain.
Is Struts Compatible With Other Java Technologies?
Yes. Struts is committed to supporting industry standards. Struts acts as an integrator of Java technologies so that they can be used in the "real world".
Who Wrote Struts?
There are several active committers to the Struts project, working cooperatively from around the globe. Dozens of individual developers and committers contributed to the Struts 1.x codebase. All interested Java developers are invited to contribute to the project. Struts is a Apache Software Foundation project, with the mission to "provide secure, enterprise-grade server solutions based on the Java Platform that are developed in an open and cooperative fashion".
Struts was created by Craig R. McClanahan and donated to The Apache Software Foundation in May 2000. Craig was the primary developer of both Struts 1.x and Tomcat 4. Tomcat 4 was the basis for the official reference implementation for a servlet 2.3 and JSP 1.2 container.
Craig's current focus is as architect of the Sun Java Studio Creator (formerly Project Rave). Craig also serves as the Specification Lead for JavaServer Faces (JSR-127), and is the Web Layer Architect for the Java2 Enterprise Edition (J2EE) platform as a whole.
Why Is It Called Struts?
It's a reference to struts in the architectural sense, a reminder of the nearly invisible pieces that hold up buildings, houses, and bridges.
Do I Have To Credit Struts On My Own Website?
You need to credit Struts if you redistribute your own framework based on Struts for other people to use. (See the Apache License for details.) But you do not need to credit Struts just because your web application utilizes the framework. It's the same situation as using the Apache HTTPD server or Tomcat. Not required if its just running your web site.
Where Can I Get A Copy Of Struts?
The best place to download Struts is at struts.apache.org. The nightly builds are very stable, and recommended as the best place to start today.
How Do I Install Struts?
To develop applications with Struts, you can usually just add the Struts JAR file to your Java development environment. You can then start using the Struts classes as part of your own application. A blank Struts application (in the webapps directory, open struts-blank.war) is provided, which you can just copy to get a quick-start on your own brainchild.
Since the full source code for Struts is available, we also provide complete instructions for compiling your own Struts JAR from scratch. (This is actually easier than it looks!)
Your Struts application can usually be deployed using a standard WAR file. In most cases, you simply deposit the WAR file on your application server, and it is installed automatically. If not, step-by-step installation instructions for various servlet containers are available.
When Do I Need "struts.jar" On My Classpath?
When you are compiling an application that uses the Struts classes, you must have the "struts.jar" on the classpath your compiler sees -- it does not have to be on your CLASSPATH environment variable.
Why is that an important distinction? Because if you are using a servlet container on your development machine to test your application, the "struts.jar" must not be on your CLASSPATH environment variable when running the container. (This is because each Web application must also have their own copy of the Struts classes, and the container will become confused if it is on the environment path as well.)
There are several general approaches to this issue
* Use ANT for building your projects -- it can easily assemble classpaths for the compiler. (This is how Struts itself is built, along with Tomcat and most other Java-based projects).
* Use an IDE where you can configure the "class path" used for compilation independent of the CLASSPATH environment variable.
* Use a shell script that temporarily adds struts.jar to the classpath just for compilation, for example javac -classpath /path/to/struts.jar:$CLASSPATH $@
Does Struts Include Its Own Unit Tests?
Struts currently has two testing environments, to reflect the fact that some things can be tested statically, and some really need to be done in the environment of a running servlet container.
For static unit tests, we use the JUnit framework. The sources for these tests are in the "src/test" hierarchy in the source repository, and are executed via the "test.junit" target in the top-level build.xml file. Such tests are focused on the low-level functionality of individual methods, are particularly suitable for the static methods in the org.apache.struts.util utility classes. In the test hierarchy, there are also some "mock object" classes (in the org.apache.struts.mock package) so that you can package up things that look like servlet API and Struts API objects to pass in as arguments to such tests.
Another valuable tool is Struts TestCase which provides a useful harness for Action classes that can be used with JUnit or Cactus.
What Is The Design Role Played By Struts?
The role played by Structs is controller in Model/View/Controller(MVC) style. The View is played by JSP and Model is played by JDBC or generic data source classes. The Struts controller is a set of programmable components that allow developers to define exactly how the application interacts with the user.
How Struts Control Data Flow?
Struts implements the MVC/Layers pattern through the use of ActionForwards and ActionMappings to keep control-flow decisions out of presentation layer.
What Configuration Files Are Used In Struts?
ApplicationResources.properties
struts-config.xml
These two files are used to bridge the gap between the Controller and the Model.
What Helpers In The Form Of Jsp Pages Are Provided In Struts Framework?
--struts-html.tld
--struts-bean.tld
--struts-logic.tld
Is Struts Efficient?
The Struts is not only thread-safe but thread-dependent(instantiates each Action once and allows other requests to be threaded through the original object.
ActionForm beans minimize subclass code and shorten subclass hierarchies.
The Struts tag libraries provide general-purpose functionality.
The Struts components are reusable by the application.
The Struts localization strategies reduce the need for redundant JSPs.
The Struts is designed with an open architecture--subclass available.
The Struts is lightweight (5 core packages, 5 tag libraries).
The Struts is open source and well documented (code to be examined easily).
The Struts is model neutral.
How You Will Enable Front-end Validation Based On The Xml In Validation.xml?
The < html:javascript > tag to allow front-end validation based on the xml in validation.xml. For example the code: < html:javascript formName=logonForm dynamicJavascript=true staticJavascript=true / > generates the client side java script for the form logonForm as defined in the validation.xml file. The < html:javascript > when added in the jsp file generates the client site validation script.
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| NetSuite Most Frequently Asked Latest Advanced Java Interview Questions Answers |
What Is Actionservlet?
The class org.apache.struts.action.ActionServlet is the called the ActionServlet. In the the Jakarta Struts Framework this class plays the role of controller. All the requests to the server goes through the controller. Controller is responsible for handling all the requests.
How You Will Make Available Any Message Resources Definitions File To The Struts Framework Environment?
Message Resources Definitions file are simple .properties files and these files contains the messages that can be used in the struts project. Message Resources Definitions files can be added to the struts-config.xml file through < message-resources / > tag. Example: < message-resources parameter= MessageResources / >
What Is Action Class?
The Action Class is part of the Model and is a wrapper around the business logic. The purpose of Action Class is to translate the HttpServletRequest to the business logic. To use the Action, we need to Subclass and overwrite the execute() method. In the Action Class all the database/business processing are done. It is advisable to perform all the database related stuffs in the Action Class. The ActionServlet (commad) passes the parameterized class to Action Form using the execute() method. The return type of the execute method is ActionForward which is used by the Struts Framework to forward the request to the file as per the value of the returned ActionForward object.
Write Code Of Any Action Class?
Here is the code of Action Class that returns the ActionForward object.
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
public class TestAction extends Action
{
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) throws Exception
{
return mapping.findForward(\"testAction\");
}
}
What Is Actionform?
An ActionForm is a JavaBean that extends org.apache.struts.action.ActionForm. ActionForm maintains the session state for web application and the ActionForm object is automatically populated on the server side with data entered from a form on the client side.
What Is Struts Validator Framework?
Struts Framework provides the functionality to validate the form data. It can be use to validate the data on the users browser as well as on the server side. Struts Framework emits the java scripts and it can be used validate the form data on the client browser. Server side validation of form can be accomplished by sub classing your From Bean with DynaValidatorForm class. The Validator framework was developed by David Winterfeldt as third-party add-on to Struts. Now the Validator framework is a part of Jakarta Commons project and it can be used with or without Struts. The Validator framework comes integrated with the Struts Framework and can be used without doing any extra settings.
Give The Details Of Xml Files Used In Validator Framework?
The Validator Framework uses two XML configuration files validator-rules.xml and validation.xml. The validator-rules.xml defines the standard validation routines, these are reusable and used in validation.xml. to define the form specific validations. The validation.xml defines the validations applied to a form bean. How you will display validation fail errors on jsp page? - The following tag displays all the errors: < html:errors/ >
Why Do We Need Struts?
Java technologies give developers a serious boost when creating and maintaining applications to meet the demands of today's public Web sites and enterprise intranets. Struts combines Java Servlets, Java ServerPages, custom tags, and message resources into a unified framework. The end result is a cooperative, synergistic platform, suitable for development teams, independent developers, and everyone in between.
How Does Struts Work?
Java Servlets are designed to handle requests made by Web browsers. Java ServerPages are designed to create dynamic Web pages that can turn billboard sites into live applications. Struts uses a special Servlet as a switchboard to route requests from Web browsers to the appropriate ServerPage. This makes Web applications much easier to design, create, and maintain.
Is Struts Compatible With Other Java Technologies?
Yes. Struts is committed to supporting industry standards. Struts acts as an integrator of Java technologies so that they can be used in the "real world".
Who Wrote Struts?
There are several active committers to the Struts project, working cooperatively from around the globe. Dozens of individual developers and committers contributed to the Struts 1.x codebase. All interested Java developers are invited to contribute to the project. Struts is a Apache Software Foundation project, with the mission to "provide secure, enterprise-grade server solutions based on the Java Platform that are developed in an open and cooperative fashion".
Struts was created by Craig R. McClanahan and donated to The Apache Software Foundation in May 2000. Craig was the primary developer of both Struts 1.x and Tomcat 4. Tomcat 4 was the basis for the official reference implementation for a servlet 2.3 and JSP 1.2 container.
Craig's current focus is as architect of the Sun Java Studio Creator (formerly Project Rave). Craig also serves as the Specification Lead for JavaServer Faces (JSR-127), and is the Web Layer Architect for the Java2 Enterprise Edition (J2EE) platform as a whole.
Why Is It Called Struts?
It's a reference to struts in the architectural sense, a reminder of the nearly invisible pieces that hold up buildings, houses, and bridges.
Do I Have To Credit Struts On My Own Website?
You need to credit Struts if you redistribute your own framework based on Struts for other people to use. (See the Apache License for details.) But you do not need to credit Struts just because your web application utilizes the framework. It's the same situation as using the Apache HTTPD server or Tomcat. Not required if its just running your web site.
Where Can I Get A Copy Of Struts?
The best place to download Struts is at struts.apache.org. The nightly builds are very stable, and recommended as the best place to start today.
How Do I Install Struts?
To develop applications with Struts, you can usually just add the Struts JAR file to your Java development environment. You can then start using the Struts classes as part of your own application. A blank Struts application (in the webapps directory, open struts-blank.war) is provided, which you can just copy to get a quick-start on your own brainchild.
Since the full source code for Struts is available, we also provide complete instructions for compiling your own Struts JAR from scratch. (This is actually easier than it looks!)
Your Struts application can usually be deployed using a standard WAR file. In most cases, you simply deposit the WAR file on your application server, and it is installed automatically. If not, step-by-step installation instructions for various servlet containers are available.
When Do I Need "struts.jar" On My Classpath?
When you are compiling an application that uses the Struts classes, you must have the "struts.jar" on the classpath your compiler sees -- it does not have to be on your CLASSPATH environment variable.
Why is that an important distinction? Because if you are using a servlet container on your development machine to test your application, the "struts.jar" must not be on your CLASSPATH environment variable when running the container. (This is because each Web application must also have their own copy of the Struts classes, and the container will become confused if it is on the environment path as well.)
There are several general approaches to this issue
* Use ANT for building your projects -- it can easily assemble classpaths for the compiler. (This is how Struts itself is built, along with Tomcat and most other Java-based projects).
* Use an IDE where you can configure the "class path" used for compilation independent of the CLASSPATH environment variable.
* Use a shell script that temporarily adds struts.jar to the classpath just for compilation, for example javac -classpath /path/to/struts.jar:$CLASSPATH $@
Does Struts Include Its Own Unit Tests?
Struts currently has two testing environments, to reflect the fact that some things can be tested statically, and some really need to be done in the environment of a running servlet container.
For static unit tests, we use the JUnit framework. The sources for these tests are in the "src/test" hierarchy in the source repository, and are executed via the "test.junit" target in the top-level build.xml file. Such tests are focused on the low-level functionality of individual methods, are particularly suitable for the static methods in the org.apache.struts.util utility classes. In the test hierarchy, there are also some "mock object" classes (in the org.apache.struts.mock package) so that you can package up things that look like servlet API and Struts API objects to pass in as arguments to such tests.
Another valuable tool is Struts TestCase which provides a useful harness for Action classes that can be used with JUnit or Cactus.
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