Support for Spring Boot Embedded applications

[jbcpollak]

Hi, I'd really like to use this with an embedded Spring Boot application, can you please explain how that can be done?

[max-dev]

Hi Joshua, running LightAdmin/Spring Boot in embedded mode is not supported yet, 'cause it still needs a couple of tweaks to be done (haven't investigated it yet).

[jbcpollak]

Hi @max-dev , do you know what is needed? If you can point me in the right direction, I might be able to help out. I saw this article, I don't know if its as simple as this or not: http://stackoverflow.com/questions/20915528/how-can-i-register-a-secondary-servlet-with-spring-boot

[jimmyfm]

I tried to embed the non working demo into a real project and i had errors since boot could not find the templates

[jbcpollak]

Hi @jimmyfm - You can solve this by excluding the templates in your dependency manager, it doesn't look like LightAdmin uses them. If you use Maven, try this:

        <dependency>
            <groupId>org.lightadmin</groupId>
            <artifactId>lightadmin</artifactId>
            <version>1.0.0.M3-SNAPSHOT</version>
            <exclusions>
                <exclusion>
                    <artifactId>tiles-velocity</artifactId>
                    <groupId>org.apache.tiles</groupId>
                </exclusion>
                <exclusion>
                    <artifactId>tiles-freemarker</artifactId>
                    <groupId>org.apache.tiles</groupId>
                </exclusion>
            </exclusions>
        </dependency>

The exclusion really should be in LA's pom file.

Unfortunately, you'll get your code running, but the LA servlet still won't be initialized.

[jimmyfm]

I tried with the exclusions but i keep having the same problem:

Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Thu Aug 28 17:09:22 CEST 2014
There was an unexpected error (type=Not Found, status=404).
/views/layout/internal-layout.jsp

Here the code i used: https://github.com/jimmyfm/lightadmin-spring-boot

[jbcpollak]

@jimmyfm - I'm new to spring-boot but as far as I can tell this is a standard error page you'll see for any 404 errors, until something is registered on /error. This is happening because the LA servlet is not being started, so nothing is registered on the URL you specified ("/admin" or whatever)

If you bundle your spring-boot app as a war and deploy it into a servlet container, you should see LA start correctly. I created this bug to sort out how to get the servlet started correctly when built as a jar.

[max-dev]

BTW, I've already dropped tiles-velocity & tiles-freemarker dependencies. You don't have to exclude them explicitly anymore.

[max-dev]

Hi @jbcpollak, I've almost finished with stabilization of the latest LightAdmin version. Right after finishing, I'll take a look at "embedded" mode.

[max-dev]

@jimmyfm @jbcpollak: Successfully ran lightadmin-spring-boot in embedded mode (tomcat)

[jbcpollak]

Hi @max-dev - This is great news. Is a compatible version published to a maven repo? I'll try it now!

[max-dev]

It's in the latest 1.0.0.BUILD-SNAPSHOT version available from LightAdmin Nexus. Will release it to Maven Central soon.

[jbcpollak]

Ok, I am using the snapshot and added the servletContextInitializer() function, and it looks like lightadmin starts up now. I am getting this error:

    Caused by: java.lang.NoClassDefFoundError: javax/servlet/jsp/JspFactory
        at org.lightadmin.core.view.LightAdminSpringTilesInitializer$SpringTilesContainerFactory.createAttributeEvaluatorFactory(LightAdminSpringTilesInitializer.java:148) ~[lightadmin-1.0.0.BUILD-SNAPSHOT.jar:1.0.0.BUILD-SNAPSHOT]
        at org.apache.tiles.factory.BasicTilesContainerFactory.createContainer(BasicTilesContainerFactory.java:106) ~[tiles-core-2.2.2.jar:2.2.2]
        at org.apache.tiles.startup.AbstractTilesInitializer.createContainer(AbstractTilesInitializer.java:124) ~[tiles-core-2.2.2.jar:2.2.2]

I'm not sure why, I assume it is a dependency issue, but I'll dig into it.

[max-dev]

Have you checked you POM against the one from LightAdmin-SpringBoot project? javax.servlet.jsp.JspFactory is located in tomcat-embed-jasper dependency.

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-jetty</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

[jbcpollak]

ok, I got it working. I had to downgrade my tomcat version from 8.0.9 to 8.0.8 and add this dependency (which you had in your example). Oddly enough, it works with scope=provided, which doesn't make much sense to me.

Tomcat is the default, so I don't think you need to exclude jetty and include tomcat. I don't have that and am using Tomcat. In-fact, I had the opposite for a while trying to get Jetty working, but eventually gave up.

    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        <scope>provided</scope>
    </dependency>

Thanks again for working on this!

[jimmyfm]

How do you compile and launch the spring boot application?

To compile i use

mvn clean package

Then i launch with

java $JAVA_OPTS -Dserver.port=$PORT -jar target/*.jar

The maven package create a runnable jar with this manifest

Manifest-Version: 1.0
Build-Jdk: 1.7.0_65
Start-Class: org.lightadmin.boot.LightAdminBootApplication
Created-By: Apache Maven 3.0.5
Spring-Boot-Version: 1.1.5.RELEASE
Main-Class: org.springframework.boot.loader.JarLauncher
Archiver-Version: Plexus Archiver

And launching trough org.springframework.boot.loader.JarLauncher as described below bring up the error i posted earlier. Sorry for not digging deeper in the first place.

[jbcpollak]

@jimmyfm - try making your main class look like this:

https://github.com/la-team/light-admin/blob/d227683fe8fa67ff0abb4a2d63eab9dce1e0afc1/lightadmin-spring-boot/src/main/java/org/lightadmin/boot/LightAdminBootApplication.java

And you might want to check out this entire project as a template:

https://github.com/la-team/light-admin/tree/d227683fe8fa67ff0abb4a2d63eab9dce1e0afc1/lightadmin-spring-boot

[jimmyfm]

I used exactly that class, before posting again i cloned the latest version of the lightadmin-spring-boot and started from there with the process i described below.

Just to be sure here the code to replicate the error: https://github.com/jimmyfm/lightadmin-spring-boot

[max-dev]

@jimmyfm I've just finished releasing the last version 1.0.0.RELEASE and checked embedded mode works as expected. Please clone the latest lightadmin-spring-boot and run it using:

$ mvn package && java -jar target/lightadmin-boot.jar

or

$ mvn spring-boot:run

And you should have it up and running on localhost:8080/admin. Feel free to ask any questions