If your host and port is different, then you need to make changes in URL accordingly. We can configure JSP just like servlets in web. Notice that container will create two instances in this case and both will have their own servlet config objects, you can confirm this by visiting these URLs in browser. If you will make further requests, the hashcode value will not change because the requests are processed by spawning a new thread by the container.
All the core JSP interfaces and classes are defined in javax. Expression Language API interfaces are classes are part of javax. JSP Tag Libraries interfaces and classes are defined in javax. Similar to PrintWriter in servlets with additional facility of buffering support. This class extends java. Writer and container provide their own implementation for this abstract class and use it while translating JSP page to Servlet.
Apache Tomcat concrete class for JspWriter is org. JspContext serves as the base class for the PageContext class and abstracts all information that is not specific to servlets. The JspContext provides mechanism to obtain the JspWriter for output, mechanism to work with attributes and API to manage the various scoped namespaces.
A PageContext instance provides access to all the namespaces associated with a JSP page, provides access to several page attributes, as well as a layer above the implementation details. Implicit objects are added to the pageContext automatically.
The JspFactory is an abstract class that defines a number of factory methods available to a JSP page at runtime for the purposes of creating instances of various interfaces and classes used to support the JSP implementation.
If JSP pages throw JspException then errorpage mechanism is used to present error information to user. Exception to be used by a Tag Handler to indicate some unrecoverable error. Exception to indicate the calling page must cease evaluation. Thrown by a simple tag handler to indicate that the remainder of the page must not be evaluated.
They take all our details and store it in a database or cache. After filling all these details we have submit button, on click of that button all the details will be stored. Code Line Here we are taking a form name which has action i. The request will be processed through POST method. Code Line Here we are taking input type as password this will hide the password when typed and name as password.
Code Line Here we are taking a button of type submit and value is also submit. Code Line Here we are fetching the values from request i.
The " include " directive lets you include another file s at the time when the JSP page is compiled into a servlet. You can use include directive to include navigation bar, copyright statement, logo, etc. The syntax is:. Notice that JSP carries out the presentation much better and neater than servlet. The presentation can be changed easily with JSP. Whereas, in the case of servlet, you have to explicitly code all the HTML tags inside the servlet program and re-compile the program.
Let's write the " order. The advantages of JSP are: Separation of static and dynamic contents : JSP enables the separation of static contents from dynamic contents.
The dynamic contents are generated via programming logic and inserted into the static template. This greatly simplifies the creation and maintenance of web contents. Reuse of components and tag libraries: The dynamic contents can be provided by reusable components such as JavaBean, Enterprise JavaBean EJB and tag libraries - you do not have to re-inventing the wheels.
The method request. The relevant part of the generated servlet is extracted as follows with some simplifications : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 out.
Hence, the expression will be evaluated, and the result of the evaluation written out as part of the response message.
Revisit Java Servlets A typical Java servlet as shown below contains three kinds of methods: init , destroy , and one or more service methods such as doGet and doPost. No " action " attribute is specified, the default " action " is the current page i. JSP can be easily managed because we can easily separate our business logic with presentation logic. In Servlet technology, we mix our business logic with the presentation logic.
If JSP page is modified, we don't need to recompile and redeploy the project. The Servlet code needs to be updated and recompiled if we have to change the look and feel of the application. Moreover, we can use EL, implicit objects, etc.
After that, Servlet page is compiled by the compiler and gets converted into the class file. Moreover, all the processes that happen in Servlet are performed on JSP later like initialization, committing response to the browser and destroy.
We have saved this file as index. Put it in a folder and paste the folder in the web-apps directory in apache tomcat to run the JSP page.
We will learn scriptlet tag later. No, there is no need of directory structure if you don't have class files or TLD files. For example, put JSP files in a folder directly and deploy that folder. It will be running fine. The directory structure of JSP page is same as Servlet. JavaTpoint offers too many high quality services.
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