JSP Components

Components of JavaServer Pages JavaServer Pages are composed of standard HTML tags and JSP tags. JavaServer Pages support all HTML tags. For a listing of HTML tags, refer to your HTML manual.

The JSP components are categorized as follows:

Directives
Declarations
Scriptlets
Comments
Expressions

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 ofJDK installation. 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 jspComponents.jsp.
Click Finish.
Eclipse IDE will generate some boilerplate code. We just clear all its content and replace with the followings code:

<%@page import="java.util.Calendar"%>
<h3>JSPs components</h3>
<%--<%!String test = "Hello World";%> --%>
<!-- get system time -->
<%!private boolean isAM() {
		boolean am = false;
		if (Calendar.getInstance().get(Calendar.AM_PM) == Calendar.AM) {
			am = true;
		}
		return am;
	}

	String systemTime = Calendar.getInstance().getTime().toString();
%>

<%if (isAM()) {%>
	Good morning. The time is: <%=systemTime%>
<%} else {%>
	Good afternoon. The time is: <%=systemTime%>
<%}%>

<%@page import="java.util.Calendar"%>

<h3>JSPs components</h3>

<%--<%!String test = "Hello World";%> --%>

<%!private boolean isAM() {

boolean am = false;

if (Calendar.getInstance().get(Calendar.AM_PM) == Calendar.AM) {

am = true;

}

return am;

}

String systemTime = Calendar.getInstance().getTime().toString();

<%if (isAM()) {%>

Good morning. The time is: <%=systemTime%>

<%} else {%>

Good afternoon. The time is: <%=systemTime%>

<%}%>

The example above contains all JSPs components. Each of these categories is described in more detail in the next chapters.

Line 1: page directive
Lines 3, 4: comments
Lines 5-14: declarations
Lines 16, 18, 20: scriptlets
Lines 17, 19: between <%= %> are expressions

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/jspComponents.jsp

Output

JSPs components
Good afternoon. The time is: Tue Dec 01 15:00:37 ICT 2015

1 2	JSPs components Good afternoon. The time is: Tue Dec 01 15:00:37 ICT 2015

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.

Make Things Simple

Java Server Pages