vhkrausser / embedded-jetty-jsp

Example of Embedded Jetty with JSP support

Example: Embedded Jetty w/ JSP Support

This is a maven project, to build it:

$ mvn clean package

To run the example org.eclipse.jetty.demo.Main:

$ mvn exec:exec

Open your web browser to:

http://localhost:8080/  

To stop Jetty:

use CTRL+C

Code Of Interest

See org.eclipse.jetty.demo.Main

Use JavaC, Not Eclipse JDT

By default, the JSP implementation will use an internal eclipse JDT compiler, Using this system property will disable that behavior and instead use the JDK JavaC built-in compiler.

// Set JSP to use Standard JavaC always
System.setProperty("org.apache.jasper.compiler.disablejsr199","false");

Set a Servlet Temp Directory

It is important for JSP to define a temp directory suitable for managing itself. Such a directory will be used for converting the JSP source into a java file and then compiling it into a class. A sub directory in this temp directory will be automatically added by the JSP implementation for loading the compiled JSP classes.

context.setAttribute("javax.servlet.context.tempdir",scratchDir);

Set a non-System Classloader

The JSP implementation will refuse to the System Classloader (per JSTL + JSP spec), this will wrap the system classloader in a simple URLClassLoader suitable for use by the JSP implementation.

// Set Classloader of Context to be sane (needed for JSTL)
// JSP requires a non-System classloader, this simply wraps the
// embedded System classloader in a way that makes it suitable
// for JSP to use
ClassLoader jspClassLoader = new URLClassLoader(new URL[0], this.getClass().getClassLoader());
context.setClassLoader(jspClassLoader);

Jsp Servlet must be named "jsp"

The JspServlet must be named "jsp" (per JSP spec).

// Add JSP Servlet (must be named "jsp")
ServletHolder holderJsp = new ServletHolder("jsp",JspServlet.class);
holderJsp.setInitOrder(0);

Default Servlet must exist

The JSP implementation relies on various Servlet Spec requirements, but mainly the fact that a "default" named servlet must exist.

// Add Default Servlet (must be named "default")
ServletHolder holderDefault = new ServletHolder("default",DefaultServlet.class);
holderDefault.setInitParameter("resourceBase",baseUri.toASCIIString());
holderDefault.setInitParameter("dirAllowed","true");
context.addServlet(holderDefault,"/");