Make EL work with tomcat 7 embedded (using spring MVC)

Question

I made an example, available on github, that uses tomcat embedded to boot a simple spring MVC application. The application boot with apparently no problem, but in the rendered jsp, el expression is not processed.

Here is my pom.xml :

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>springtomcatembedded</artifactId>
    <name>SpringMVCTomcatEmbedded</name>
    <packaging>war</packaging>
    <version>1.0.0-BUILD-SNAPSHOT</version>
    <properties>
        <java-version>1.6</java-version>
        <org.springframework-version>3.1.1.RELEASE</org.springframework-version>
        <org.aspectj-version>1.6.10</org.aspectj-version>
        <org.slf4j-version>1.6.6</org.slf4j-version>
        <tomcat.version>7.0.50</tomcat.version>
    </properties>
    <dependencies>
        <!-- Spring -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${org.springframework-version}</version>
            <exclusions>
                <!-- Exclude Commons Logging in favor of SLF4j -->
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>

        <!-- AspectJ -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>${org.aspectj-version}</version>
        </dependency>

        <!-- Logging -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${org.slf4j-version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>${org.slf4j-version}</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${org.slf4j-version}</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.15</version>
            <exclusions>
                <exclusion>
                    <groupId>javax.mail</groupId>
                    <artifactId>mail</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.jms</groupId>
                    <artifactId>jms</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.sun.jdmk</groupId>
                    <artifactId>jmxtools</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.sun.jmx</groupId>
                    <artifactId>jmxri</artifactId>
                </exclusion>
            </exclusions>
            <scope>runtime</scope>
        </dependency>

        <!-- @Inject -->
        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>

        <!-- Servlet -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.2</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
            <scope>provided</scope>
        </dependency>

        <!-- Embedded tomcat -->
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-core</artifactId>
            <version>${tomcat.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-logging-juli</artifactId>
            <version>${tomcat.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <version>${tomcat.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jasper</artifactId>
            <version>${tomcat.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jasper-el</artifactId>
            <version>${tomcat.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-el-api</artifactId>
            <version>${tomcat.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jsp-api</artifactId>
            <version>${tomcat.version}</version>
        </dependency>

        <!-- Test -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.7</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-eclipse-plugin</artifactId>
                <version>2.9</version>
                <configuration>
                    <additionalProjectnatures>
                        <projectnature>org.springframework.ide.eclipse.core.springnature</projectnature>
                    </additionalProjectnatures>
                    <additionalBuildcommands>
                        <buildcommand>org.springframework.ide.eclipse.core.springbuilder</buildcommand>
                    </additionalBuildcommands>
                    <downloadSources>true</downloadSources>
                    <downloadJavadocs>true</downloadJavadocs>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                    <compilerArgument>-Xlint:all</compilerArgument>
                    <showWarnings>true</showWarnings>
                    <showDeprecation>true</showDeprecation>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.2.1</version>
                <configuration>
                    <mainClass>org.test.int1.Main</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

And here is my main spring controller wich contains also my main method :

package com.example.springtomcatembedded;

import java.io.File;
import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;

import org.apache.catalina.Context;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.Wrapper;
import org.apache.catalina.deploy.ApplicationListener;
import org.apache.catalina.deploy.ApplicationParameter;
import org.apache.catalina.startup.Tomcat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.DispatcherServlet;

/**
 * Handles requests for the application home page.
 */
@Controller
public class HomeController {

    private static final Logger logger = LoggerFactory.getLogger(HomeController.class);

    /**
     * Simply selects the home view to render by returning its name.
     */
    @RequestMapping(value = "/", method = RequestMethod.GET)
    public String home(Locale locale, Model model) {
        logger.info("Welcome home! The client locale is {}.", locale);

        Date date = new Date();
        DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, locale);

        String formattedDate = dateFormat.format(date);

        model.addAttribute("serverTime", formattedDate );

        return "home";
    }

    public static void main(String[] args) throws LifecycleException {
        Tomcat tomcat = new Tomcat();
        tomcat.setPort(8080);

        Context ctx = tomcat.addContext("/", new File("src/main/webapp/").getAbsolutePath());
        ApplicationParameter rootContextConfiguration = new ApplicationParameter();
        rootContextConfiguration.setName("contextConfigLocation");
        rootContextConfiguration.setValue("/WEB-INF/spring/root-context.xml");
        ctx.addApplicationParameter(rootContextConfiguration);
        ApplicationListener springApplicationListener = new ApplicationListener("org.springframework.web.context.ContextLoaderListener", false);
        ctx.addApplicationListener(springApplicationListener);

        // Configure dispatcher servlet
        Wrapper wrapper = ctx.createWrapper();
        String servletName = "appServlet";
        wrapper.setName(servletName);
        wrapper.setLoadOnStartup(1);
        wrapper.setServletClass(DispatcherServlet.class.getName());
        wrapper.addInitParameter("contextConfigLocation", "/WEB-INF/spring/appServlet/servlet-context.xml");
        wrapper.setLoadOnStartup(1);

        // Define JspServlet.
        Wrapper jspServlet = ctx.createWrapper();
        jspServlet.setName("jsp");
        jspServlet.setServletClass("org.apache.jasper.servlet.JspServlet");
        jspServlet.addInitParameter("fork", "false");
        jspServlet.addInitParameter("xpoweredBy", "false");
        jspServlet.setLoadOnStartup(2);
        ctx.addChild(jspServlet);
        ctx.addServletMapping("*.jsp", "jsp");

        ctx.addChild(wrapper);
        ctx.addServletMapping("/", servletName);
        tomcat.setSilent(false);
        tomcat.start();
        tomcat.getServer().await();

    }
}

My jsp page :

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page session="false" %>
<html>
<head>
    <title>Home</title>
</head>
<body>
<h1>
    Hello world!  
</h1>

<P>  The time on the server is ${serverTime}. </P>
</body>
</html>

And finally, my spring mvc configuration :

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:beans="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->

    <!-- Enables the Spring MVC @Controller programming model -->
    <annotation-driven />

    <!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
    <resources mapping="/resources/**" location="/resources/" />

    <!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
    <beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <beans:property name="prefix" value="WEB-INF/views/" />
        <beans:property name="suffix" value=".jsp" />
    </beans:bean>

    <context:component-scan base-package="com.example.springtomcatembedded" />



</beans:beans>

As I said, it is working, but my jsp pages cannot use el to access model data :S Anyone can see why ? For instance, it will print ${serverTime} instead of the actual server time pushed in the model.

Carthy

You're saying it renders as ${serverTime}? – Rebak

Yes, I updated the question to specify. – Carthy

Answer 1

Try to add:

<%@ page isELIgnored="false" %>

to the header of your jsp page. For example:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page session="false" %>
<%@ page isELIgnored="false" %>
<html>
<head>
    <title>Home</title>
</head>
<body>
<h1>
    Hello world!  
</h1>

<P>  The time on the server is ${serverTime}. </P>
</body>
</html>

---

EDIT:

Inspired by your comment:

If you want to programmatically enable EL expressions in JSP without loading/definition of a web.xml file you have to add the ContextConfig LifecycleListener:

rootContext.addLifecycleListener(new ContextConfig());

a full workin example (Tomcat embedded 7.0.50 with JDK 1.7):

public static void main(String[] args) throws LifecycleException
{
  // setup server
  final Tomcat tomcat = new Tomcat();
  tomcat.setBaseDir("."); // location where temp dir is created
  tomcat.setPort(8080);

  // configure context
  final File applicationPath = new File("./webapp"); // todo: change to your location
  Context rootContext = tomcat.addContext("/", applicationPath.getAbsolutePath());
  rootContext.addLifecycleListener(new ContextConfig());

  // JSP and Default Servlet setup, mime type mapping and welcome files
  Tomcat.initWebappDefaults(rootContext);

  // start server
  tomcat.start();
  tomcat.getServer().await();
}

with this solution you don't need to explicitly state page directives in your JSP files.

HINT: dont forget to delete your "work" (=temporary tomcat directory) after makin changes and before restarting your server. Compiled JSP's are chached there and you may get old results!

HTH,

Easter

Hehe, I did resolve my problem exactly like this and was about to post the solution :) I still wonder why it seems to ignore el by default when using tomcat-embed while el seems to be enable by default when I download and install tomcat. Also, I did not manage to enable el programmatically in my main method. I could have done it if I had a web.xml file tough. Thank you for your answer. – Carthy

Answer 2

<%@ page isELIgnored="false" %> was the root of the problem in my case. not clear why yet. tomcat7

Calvano