Spring provides special class DelegatingVariableResolver to integrate JSF and Spring together in a seamless manner.
Following steps are required to integrate Spring Dependency Injection (IOC) feature in JSF.
Add a variable-resolver entry in faces-config.xml to point to spring class DelegatingVariableResolver.
<faces-config> <application> <variable-resolver> org.springframework.web.jsf.DelegatingVariableResolver </variable-resolver> ... </faces-config>
Add ContextLoaderListener and RequestContextListener listener provided by spring framework in web.xml.
<web-app> ... <!-- Add Support for Spring --> <listener> <listener-class> org.springframework.web.context.ContextLoaderListener </listener-class> </listener> <listener> <listener-class> org.springframework.web.context.request.RequestContextListener </listener-class> </listener> ... </web-app>
Define bean(s) in applicationContext.xml which will be used as dependency in managed bean.
<beans> <bean id = "messageService" class = "com.howcodex.test.MessageServiceImpl"> <property name = "message" value = "Hello World!" /> </bean> </beans>
DelegatingVariableResolver first delegates value lookups to the default resolver of the JSF and then to Spring's WebApplicationContext. This allows one to easily inject springbased dependencies into one's JSF-managed beans.
We've injected messageService as spring-based dependency here.
<faces-config> ... <managed-bean> <managed-bean-name>userData</managed-bean-name> <managed-bean-class>com.howcodex.test.UserData</managed-bean-class> <managed-bean-scope>request</managed-bean-scope> <managed-property> <property-name>messageService</property-name> <value>#{messageService}</value> </managed-property> </managed-bean> </faces-config>
//jsf managed bean public class UserData { //spring managed dependency private MessageService messageService; public void setMessageService(MessageService messageService) { this.messageService = messageService; } public String getGreetingMessage() { return messageService.getGreetingMessage(); } }
Let us create a test JSF application to test spring integration.
Step | Description |
---|---|
1 | Create a project with a name helloworld under a package com.howcodex.test as explained in the JSF - First Application chapter. |
2 | Modify pom.xml as explained below. |
3 | Create faces-config.xml in WEB-INF folder as explained below. |
4 | Modify web.xml as explained below. |
5 | Create applicationContext.xml in WEB-INF folder as explained below. |
6 | Create MessageService.java under package com.howcodex.test as explained below. |
7 | Create MessageServiceImpl.java under package com.howcodex.test as explained below. |
8 | Create UserData.java under package com.howcodex.test as explained below. |
9 | Modify home.xhtml as explained below. Keep the rest of the files unchanged. |
10 | Compile and run the application to make sure the business logic is working as per the requirements. |
11 | Finally, build the application in the form of war file and deploy it in Apache Tomcat Webserver. |
12 | Launch your web application using appropriate URL as explained below in the last step. |
<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.howcodex.test</groupId> <artifactId>helloworld</artifactId> <packaging>war</packaging> <version>1.0-SNAPSHOT</version> <name>helloworld Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>com.sun.faces</groupId> <artifactId>jsf-api</artifactId> <version>2.1.7</version> </dependency> <dependency> <groupId>com.sun.faces</groupId> <artifactId>jsf-impl</artifactId> <version>2.1.7</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.1.2.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>3.1.2.RELEASE</version> </dependency> </dependencies> <build> <finalName>helloworld</finalName> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>2.3.1</version> <configuration> <source>1.6</source> <target>1.6</target> </configuration> </plugin> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>2.6</version> <executions> <execution> <id>copy-resources</id> <phase>validate</phase> <goals> <goal>copy-resources</goal> </goals> <configuration> <outputDirectory>${basedir}/target/helloworld/resources </outputDirectory> <resources> <resource> <directory>src/main/resources</directory> <filtering>true</filtering> </resource> </resources> </configuration> </execution> </executions> </plugin> </plugins> </build> </project>
<?xml version = "1.0" encoding = "UTF-8"?> <faces-config xmlns = "http://java.sun.com/xml/ns/javaee" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation = "http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_2_0.xsd" version = "2.0"> <application> <variable-resolver> org.springframework.web.jsf.DelegatingVariableResolver </variable-resolver> </application> <managed-bean> <managed-bean-name>userData</managed-bean-name> <managed-bean-class>com.howcodex.test.UserData</managed-bean-class> <managed-bean-scope>request</managed-bean-scope> <managed-property> <property-name>messageService</property-name> <value>#{messageService}</value> </managed-property> </managed-bean> </faces-config>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <context-param> <param-name>javax.faces.PROJECT_STAGE</param-name> <param-value>Development</param-value> </context-param> <!-- Add Support for Spring --> <listener> <listener-class> org.springframework.web.context.ContextLoaderListener </listener-class> </listener> <listener> <listener-class> org.springframework.web.context.request.RequestContextListener </listener-class> </listener> <servlet> <servlet-name>Faces Servlet</servlet-name> <servlet-class>javax.faces.webapp.FacesServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>Faces Servlet</servlet-name> <url-pattern>*.jsf</url-pattern> </servlet-mapping> </web-app>
<?xml version = "1.0" encoding = "UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd"> <beans> <bean id = "messageService" class = "com.howcodex.test.MessageServiceImpl"> <property name = "message" value = "Hello World!" /> </bean> </beans>
package com.howcodex.test; public interface MessageService { String getGreetingMessage(); }
package com.howcodex.test; public class MessageServiceImpl implements MessageService { private String message; public String getGreetingMessage() { return message; } public String getMessage() { return message; } public void setMessage(String message) { this.message = message; } }
package com.howcodex.test; import java.io.Serializable; public class UserData implements Serializable { private static final long serialVersionUID = 1L; private MessageService messageService; public MessageService getMessageService() { return messageService; } public void setMessageService(MessageService messageService) { this.messageService = messageService; } public String getGreetingMessage() { return messageService.getGreetingMessage(); } }
<?xml version = "1.0" encoding = "UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns = "http://www.w3.org/1999/xhtml" xmlns:f = "http://java.sun.com/jsf/core" xmlns:h = "http://java.sun.com/jsf/html"> <h:head> <title>JSF Tutorial!</title> </h:head> <h:body> <h2>Spring Integration Example</h2> #{userData.greetingMessage} </h:body> </html>
Once you are ready with all the changes done, let us compile and run the application as we did in JSF - First Application chapter. If everything is fine with your application, this will produce the following result.