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How do you compile servlet in java using tomcat?
Tomcat is a server. It is used to deploy and run Servlets and not compile them. A Servlet is a java file and has to be compiled just like any other Java Class.
What does it mean if the class average is 40 percent?
It means that the majority of the class is failing and it could be either that the assignment/test/quiz is too hard or the teacher/professor is not good at teaching and is a hard marker.
How do you use Calculus in a sentence?
My Calculus class is in third period. Calculus is a noun
Can i take remedial classes and credit class in college at the same time?
Should get credit for any type
Can I take an MCAT class online?
You can only take the pretest online. You can visit www.kaptest.com to take it for free.
How many interfaces in a java servlet package?
The javax.servlet package defines 12 interfaces, 7 classes, and 2 exceptions. The Interfaces are as follows:• Filter:- Preprocessor of the request before it reaches a servlet. It can also be a postprocessor of the response leaving a servlet. It can modify a request or response (for example, change headers), the request to a resource (a servlet or static content), or the response from a resource.• RequestDispatcher:- This is the servlet version of a redirect. It enables requests to be processed and then forwarded to other components of a Web application, such as another servlet, HTML file, or JSP file.• Servlet:- Defines the life-cycle methods that are implemented by all servlets.• ServletConfig:- This class has the methods for accessing the servlet configuration information such as the servlets name (from the web.xml file), the initialization parameters, and the ServletContext object.• ServletContext:- These methods enable your servlet to communicate with its servlet container. This is how you get the MIME type of a file, dispatch requests, or write to a log file. Notice that this information has application scope. The most important features of the ServletContext are application-scope attributes access, logging, and context initialization parameters.• ServletContextAttributeListener:- Implementations of this interface receive notifications of changes to the attribute list on the servlet context of a Web application. Supports the handling of the ServletContextAttributeEvent class.• ServletContextListener:- An interface that supports the handling of the ServletContextEvent class. Defines a set of methods that a servlet uses to communicate with its servlet container. It can get the MIME type of a file, dispatch requests, or write to a log file. Notice that there is one context per "Web application" per Java Virtual Machine. The specification defines a "Web application" as a collection of servlets and content installed under a specific subset of the server's URL namespace, such as /catalog, and possibly installed via a .war file.• ServletRequest:- This interface forms the base for the class that provides client request information to a servlet. It is protocol-independent.• ServletResponse:- This interface forms the base for the class that represents the response sent from the servlet to the client.• SingleThreadModel:- An interface that ensures a given servlet handles only one request at a time.
Why servlet has no constructor?
Because it is not a regular Java Class that is executed by a JVM. It is a special Java class that is executed by the Web Container which initializes and loads the servlet and the service methods get executed everytime it receives a request.
How does Apache httpd work?
Tomcat is a servlet container, and the following is how a servlet container works The init, service, and destroy methods are the servlet's lifecycle methods. The init method is called once by the servlet container after the servlet class has been instantiated to indicate to the servlet that it being placed into service. The init method must complete successfully before the servlet can receive any requests. A servlet programmer can override this method to write initialization code that needs to run only once, such as loading a database driver, initializing values, and so on. In other cases, this method is normally left blank. The service method is then called by the servlet container to allow the servlet to respond to a request. The servlet container passes a javax.servlet.ServletRequest object and a javax.servlet.ServletResponse object. The ServletRequest object contains the client's HTTP request information and the ServletResponse encapsulates the servlet's response. These two objects enable you to write custom code that determines how the servlet services the client request. The servlet container calls the destroy method before removing a servlet instance from service. This normally happens when the servlet container is shut down or when the servlet container needs some free memory. This method is called only after all threads within the servlet's service method have exited or after a timeout period has passed. After the servlet container calls destroy, it will not call the service method again on this servlet. The destroy method gives the servlet an opportunity to clean up any resources that are being held (for example, memory, file handles, and threads) and make sure that any persistent state is synchronized with the servlet's current state in memory. For Better Picture, Visit below article full of images to clear the concept : http://shivasoft.in/blog/java/servlet/how-container-handles-the-servlet-request/
What is the difference between an applet and a servlet?
Applet is a part of Core JAVA and Servlet of Advance Java. Applet is client side program and Servlet is Server side. When Applet runs it take the resources of client whereas Servlet is processed at server. An Applet's class, jar files can be accessed and downloadable by client but not so in case of servlet. Applets can run under any web browser their execution is dependent on Client as they require JRE Whereas Servlets do not require any thing specific at client side, as they require java enabled web/application Server. Dilpreet Singh (SCJP,OCA 9i) www.geocities.com/heartsinghThe main difference is that a servlet is a server side component while applet is a client side component, moreover, a servlet doesn't have GUI while applet have GUI. A servlet runs inside a server and results are sent to client, so it consumes less network bandwidth, and also secure, while applet runs on client side in a browser, so entire code for applet is 1st sent to client and then it is executed on the client machine itself, so it also consumes more network bandwidth.
How do you call a Servlet from JSP?
I have created a .jsp file, in which, I am calling a class.method() through TagLib. REQUIREMENT is, I want to call a servlet instead of a simple class. And Servlet will get the response, and request object from Jsp, and manipulate that, and produce the response object, and control is transfered back to JSP again.
What is difference between requestprocessor and request dispatcher?
Request processor is a class which is responsible for handling request and response it is provided by struts framework if we want to customize our controller we can make in this class. Request Dispatcher is an interface which supports for dispatching request from one page to another page in a application(page may be a servlet file,JSP
Can insert javascript coding in servlet?
No. Javascript code can be present inside a JSP but not inside a servlet. A Servlet is a pure java class.
What is servlet API in java?
Overview of the Servlet APIThe Servlet 2.3 API consists of two packages: javax.servlet and javax.servlet.http. The base functionality is defined in the javax.servlet package whose classes and interfaces outline a generic, protocol-independent implementation. This means you can use it for non-Web applications, too. Of course, the exam targets the Web, so the HTTP protocol is the only one discussed in this blog. The javax.servlet.http interface defines classes and interfaces that are specific to the Hypertext Transfer Protocol (HTTP).The javax.servlet PackageThe javax.servlet package defines 12 interfaces, 7 classes, and 2 exceptions. These interfaces, classes, and exceptions are as follows.Interfaces• Filter:- Preprocessor of the request before it reaches a servlet. It can also be a postprocessor of the response leaving a servlet. It can modify a request or response (for example, change headers), the request to a resource (a servlet or static content), or the response from a resource.• RequestDispatcher:- This is the servlet version of a redirect. It enables requests to be processed and then forwarded to other components of a Web application, such as another servlet, HTML file, or JSP file.• Servlet:- Defines the life-cycle methods that are implemented by all servlets.• ServletConfig:- This class has the methods for accessing the servlet configuration information such as the servlets name (from the web.xml file), the initialization parameters, and the ServletContext object.• ServletContext:- These methods enable your servlet to communicate with its servlet container. This is how you get the MIME type of a file, dispatch requests, or write to a log file. Notice that this information has application scope. The most important features of the ServletContext are application-scope attributes access, logging, and context initialization parameters.• ServletContextAttributeListener:- Implementations of this interface receive notifications of changes to the attribute list on the servlet context of a Web application. Supports the handling of the ServletContextAttributeEvent class.• ServletContextListener:- An interface that supports the handling of the ServletContextEvent class. Defines a set of methods that a servlet uses to communicate with its servlet container. It can get the MIME type of a file, dispatch requests, or write to a log file. Notice that there is one context per "Web application" per Java Virtual Machine. The specification defines a "Web application" as a collection of servlets and content installed under a specific subset of the server's URL namespace, such as /catalog, and possibly installed via a .war file.• ServletRequest:- This interface forms the base for the class that provides client request information to a servlet. It is protocol-independent.• ServletResponse:- This interface forms the base for the class that represents the response sent from the servlet to the client.• SingleThreadModel:- An interface that ensures a given servlet handles only one request at a time.Classes• GenericServlet:- An abstract class that implements ServletConfig. It defines a generic, protocol-independent servlet.• ServletContextAttributeEvent:- This is the event class for notifications about changes to the attributes of the servlet context of a Web application.• ServletContextEvent:- This is the event class for notifications about changes to the servlet context of a Web application (parent of ServletContextAttributeEvent).• ServletInputStream:- Provides an input stream for reading binary data from a client request. You can modify it; it already has the readLine method for reading data one line at a time.• ServletOutputStream:- An abstract class providing an output stream for sending binary data to the client. You print HTML, XML, or other output to the client using ServletOutputStream's print() and println() methods.• ServletRequestWrapper:- Provides a convenient implementation of the ServletRequest interface that can be subclassed by developers wishing to adapt the request to a Servlet. This is where you can modify the behavior of request objects.• ServletResponseWrapper:- Provides a convenient implementation of the ServletResponse interface that can be subclassed by developers wishing to adapt the response from a Servlet. This is where you can modify the behavior of response objects.Exceptions• ServletException:- Extends java.lang.Exception to provide a base class for defining servlet-related extensions.• UnavailableException:- Extends ServletException to indicate that a servlet is temporarily or permanently unavailable.The javax.servlet.http PackageThe javax.servlet.http package defines eight interfaces and seven classes. These interfaces and classes are as follows:InterfacesThe interfaces include the following:• HttpServletRequest:- Extends javax.servlet.ServletRequest to support HTTP.• HttpServletResponse:- Extends javax.servlet.ServletResponse to support HTTP.• HttpSession:- Defines methods that provide access to persistent session-state information.• HttpSessionActivationListener:- Implemented to handle the HttpSessionActivationEvent.• HttpSessionAttributeListener:- Implemented to handle the HttpSessionAttributeEvent.• HttpSessionBindingListener:- Implemented by objects that listen for HttpSessionBindingEvent events.• HttpSessionListener:- Implemented to handle the HttpSessionEvent.ClassesThe classes include the following:• Cookie:- Encapsulates HTTP cookies.• HttpServlet:- An abstract class that extends javax.servlet.GenericServlet to provide support for HTTP.• HttpServletRequestWrapper:- Provides the capability to wrap and modify incoming HttpServletRequest objects.• HttpServletResponseWrapper:- Provides the capability to wrap and modify outgoing HttpServletResponse objects.• HttpSessionBindingEvent:- Extends java.util.EventObject to define an event that is sent to an HttpSessionBindingListener when an object is bound or unbound from the current HttpSession.• HttpSessionEvent:- Parent class of HttpSessionBindingEvent.
What class is a new servlet usually inherited?
The servlet class created in web applications usually extend the javax.servlet.HttpServlet class. The HttpServlet extends the javax.servlet.GenericServlet. These classes contain the basic features that are required to run a web application.
What is servlet mapping?
A Servlet Mapping is a directive in the web.xml that tells the Servlet Container which class to use when a particular Servlet is called. A Servlet is a class within your Java Web Application. Let's say you have a servlet called MyServlet in the com.example.servlet package. You would need to have a Servlet Mapping pointing the path "/MyServlet" to the "com.example.servlet.MyServlet" class. Without the servlet mapping, you would not be able to invoke your servlet because the Servlet container would not know where it is. JSPs are different - they do not need mappings like this. JSPs exist within the WebRoot of the application, so they are always available. Servlets exist in the WEB-INF\Classes directory once your application is deployed.
What is generic servlet class?
GenericServlet defines a generic, protocol-independent servlet whereas HttpServlet Provides an abstract class to be subclassed to create an HTTP servlet suitable for a Web site that uses the Http Protocol.
What are the advantages of Servlets?
1) The servlet execute on the address space of the web server .It is not necessary to create a separate process to handle each client request 2) servlet are platform independent because they are written in java 3) The java security manager on the server enforces a set of restriction to protect the resource on a server machine 4) All the java libraries class are available to a servlet.It can communicate with applets,database,or other software via the sockets.
