Scriptlets

JSP supports embedding of Java code fragments within a JSP by using a scriptlets block. Scriptlets are used to embed small code blocks within the JSP page, rather than to declare entire methods as performed in a declarations block. The syntax for a scriptlet is:

<% scriptlet %>

The following example uses scriptlets to output an HTML message based on the time of day. You can see that the HTML elements appear outside the script declarations. isAM() method is declared in a declarative directive.

Step 1 Create new Dynamic Web Project

Step 1.1 Create New Project

Go to File->New->Others… Select Dynamic Web Project under Web category then click Next. TypeServletDemo or whatever name you want in the Project name field.

Step 1.2 Configure Target Runtime

  • Click New Runtime… button under Target Runtime.
  • Select Apache Tomcat v7.0. Click Next.
  • Click Browse button to specify Tomcat Server installation directory. The select the folder then click Ok.
  • Click Installed JREs… button to add/remove or edit JRE definition. Remove existing one; then click Add button to configure new one. Select Standard VM; then click Next. Click Directory button to select the root folder ofJDKinstallation. Select the folder then click Ok. Click Finish.
  • Check the JDK then click Ok.
  • Change JRE to the JDK then click Finish.
  • Click Finish the finish the project creation.

Step 2 Create New JSP File

  • Right click to the project or WebContent folder, select New -> JSP File from the menu.
  • You can choose any name, for example scriptletsDemo.jsp
  • Click Finish.
  • Eclipse IDE will generate some boilerplate code. We just clear all its content and replace with the followings code:

Step 3 Configure Tomcat

Select Servers window; in case it’s not there, go to Windows -> Show View-> Others… Select Server -> Servers; then click Ok.

If this is the first time you are creating a server, in the Servers area you will see a link as No servers are available click this link to create a new server. Click the link.

Define a New Server window will be opened, In Select the server type. Select Apache -> Tomcat v7.0 Server. Then click Finish.

Step 4 Deploy The Application

  • Right click to the Tomcat Server select Add and Remove.
  • Move the application (JSPDemo) from Available column to Configured. Then click on Finish to deploy it to tomcat server.

Step 5 Start Tomcat Server

Right click on the tomcat server and choose Start or simply click on the green start icon to start the server.

Step 6 Run The JSP

We assume that you install tomcat on default port (8080) and project name is JSPDemo. Open web browser and type:

http://localhost:8080/JspDemo/scriptletsDemo.jsp

Output

Note: for JSP, you don’t need to Clean & Build the project or restart the tomcat server before running. You just change the code, save the changes and run.

For java classes, you need to Clean & Build the project to re-compile the code. In case register new servlet, change settings in web.xml or server.xml… you need to Clean & Build the project and restart tomcat server.