Support JSP with Embedded Jetty

[philwebb]

Documentation lists some JSP limitations, however, some of these may have been fixed with recent 'fat jar' updates. We should revisit to see what problems still exist.

[dsyer]

Tomcat is in much better shape: the web-jsp sample works as a WAR, but not a JAR (due to the way the Tomcat explicitly only allows deployment from an archive whose name ends in ".war").

Jetty is all over the place (and never worked with executable archives at all as far as I can tell). Not even running from the IDE works because taglibs are not resolved from the classpath correctly (there's a useful looking code snippet in stackoverflow here: http://stackoverflow.com/questions/17685330/how-do-you-get-embedded-jetty-9-to-successfully-resolve-the-jstl-uri). When you try to run a WAR file you get some horrendous looking error before taglibs even start to be a problem:

2014-02-18 11:44:54.261 ERROR 13685 --- [qtp713849829-20] org.apache.jasper.servlet.JspServlet     : PWC6117: File "%2Fhome%2Fdsyer%2Fdev%2Fboot%2Fworkspace%2Fjsp%2Ftarget%2Fjsp-1.0.0.BUILD-SNAPSHOT.war%2FWEB-INF%2Fjsp%2Fwelcome.jsp" not found

[dsyer]

Jetty is a basket case, but Tomcat 7 is good (docs have been updated). I think we'll leave this open in case we can revisit after Boot 1.0. Tomcat 8 is also broken.

[sha1n]

Although not a part of the spring-boot executable jar, I managed to make JSPs work by configuring Jetty's WebAppContext's resourceBase to a local directory. For me it's more convenient, since client developers prefer to have their own workspaces and we don't see much advantage in having those files packaged in the application jar.

You can take a look here: https://github.com/sha1n/spring-boot-jetty-jersey

[sha1n]

Correction: my code doesn't actually work when I start the app from the command-line using "java -jar app.jar", it only works from the IDE. The reason is that the JSP compiler class-path is by a Jetty class named ServletHolder (method initJspServlet) by the following line:

    setInitParameter("com.sun.appserv.jsp.classpath", Loader.getClassPath(ch.getClassLoader().getParent()));not set properly when the application starts by 

When starting from the command line, the system class loader does not contain all the application dependencies and therefore the JSP compiler fails. In order to fix this, the JSP servlet initialization procedure needs to be changed to include application dependencies.

[luizguimaraes]

I have solved the "The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved..." problem in my app by setting a new classloader to jetty WebAppContext as sugest here: https://github.com/jetty-project/embedded-jetty-jsp

I'm also using the following dependency:

<dependency>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-jsp</artifactId>
</dependency>

[AlexeyPanichenko]

I have added

 <dependency>
            <groupId>org.mortbay.jetty</groupId>
            <artifactId>jsp-2.1-glassfish</artifactId>
            <version>2.1.v20100127</version>
 </dependency>

to depencencies and it started work! Taken from http://stackoverflow.com/questions/17685330/how-do-you-get-embedded-jetty-9-to-successfully-resolve-the-jstl-uri