问题
I was working on a JSF 1.x example, which has some EL conflict in JSPs.
the line actionListener="#{helloBean.addControls} is shooting an issue.
The error is :
HTTP Status 500 - /JSP/hello.jsp (line: 37, column: 2) A literal value was specified for attribute actionListener that is defined as a deferred method with a return type of void. JSP.2.3.4 does not permit literal values in this case
My project Description is as follows :
Package Structure :
Maven Dependencies :
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.achutha.labs</groupId>
<artifactId>02JsfExample</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>02JsfExample</name>
<dependencies>
<dependency>
<groupId>javax.faces</groupId>
<artifactId>jsf-api</artifactId>
<version>1.2_14</version>
</dependency>
<dependency>
<groupId>javax.faces</groupId>
<artifactId>jsf-impl</artifactId>
<version>1.2_14</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.1</version>
</dependency>
<!-- EL -->
<dependency>
<groupId>org.glassfish.web</groupId>
<artifactId>el-impl</artifactId>
<version>2.2</version>
</dependency>
</dependencies>
<build>
<finalName>JavaServerFaces</finalName>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>tomcat-maven-plugin</artifactId>
<configuration>
<url>http://localhost:8090/manager/text</url>
<server>TomcatServer</server>
<path>/balaji</path>
</configuration>
</plugin>
<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>
</plugins>
</build>
</project>
Faces Configuration :
<?xml version="1.0"?>
<!DOCTYPE faces-config PUBLIC
"-//Sun Microsystems, Inc.//DTD JavaServer Faces Config 1.0//EN"
"http://java.sun.com/dtd/web-facesconfig_1_0.dtd">
<faces-config>
<managed-bean>
<description> The one and only HelloBean.</description>
<managed-bean-name>helloBean</managed-bean-name>
<managed-bean-class>com.achutha.bean.HelloBean</managed-bean-class>
<managed-bean-scope>session</managed-bean-scope>
</managed-bean>
<navigation-rule>
<description>Navigation From the Hello Page.</description>
<from-view-id>/JSP/hello.jsp</from-view-id>
<navigation-case>
<from-outcome>success</from-outcome>
<to-view-id>/JSP/goodbye.jsp</to-view-id>
</navigation-case>
</navigation-rule>
</faces-config>
Deployment Descriptor (web.xml) :
<?xml version="1.0" encoding="UTF-8"?>
<!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>Hello, World!</display-name>
<description>Welcome to JavaServer Faces</description>
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>/faces/*</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>/JSP/hello.jsp</welcome-file>
</welcome-file-list>
</web-app>
hello.jsp
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f"%>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h"%>
<f:view>
<html>
<head>
<title>JSF In Action - Hello, world!</title>
</head>
<body>
<h:form id="welcomeForm">
<h:outputText id="welcomeOutput" value="Welcome to JavaServer Faces !"
style="font-family: Arial, sans-serif; font-size: 23; color: green;" />
<p>
<h:message id="errors" for="helloInput" style="color: red" />
</p>
<p>
<h:outputLabel for="helloInput">
<h:outputText id="helloInputLabel"
value="Enter Number of controls to display: ">
</h:outputText>
<h:inputText id="helloInput" value="#{helloBean.numControls}"
required="true">
<f:validateLongRange minimum="1" maximum="500" />
</h:inputText>
</h:outputLabel>
</p>
<p>
<h:panelGrid id="controlPanel" binding="#{helloBean.controlPanel}"
columns="20" border="1" cellspacing="0" />
</p>
<h:commandButton id="redisplayCommand" type="submit" value="Redisplay"
actionListener="#{helloBean.addControls}" />
<h:commandButton id="goodbyeCommand" type="submit" value="Goodbye"
actionListener="#{helloBean.goodbye}" immediate="true"/>
</h:form>
</body>
</html>
</f:view>
goodbye.jsp :
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h"%>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f"%>
<f:view>
<html>
<head>
<title>Jsf in Action - Hello World!</title>
</head>
<body>
<h:form id="goodbyeForm">
<p>
<h:outputText id="welcomeOutput" value="Good Bye"
style="font-family: Arial, sans-serif; font-size: 24; font-style: bold; color: green;" />
</p>
<p>
<h:outputText id="helloBeanOutputLabel"
value="Number of controls displayed: " />
<h:outputText id="helloBeanOutputLabel"
value="#{helloBean.numControls}" />
</p>
</h:form>
</body>
</html>
</f:view>
Bean class :
package com.achutha.bean;
import java.util.List;
import javax.faces.application.Application;
import javax.faces.component.UIComponent;
import javax.faces.component.html.HtmlOutputText;
import javax.faces.component.html.HtmlPanelGrid;
import javax.faces.context.FacesContext;
import javax.faces.event.ActionEvent;
public class HelloBean {
private int numControls;
private HtmlPanelGrid controlPanel;
public int getNumControls() {
return numControls;
}
public void setNumControls(int numControls) {
this.numControls = numControls;
}
public HtmlPanelGrid getControlPanel() {
return controlPanel;
}
public void setControlPanel(HtmlPanelGrid controlPanel) {
this.controlPanel = controlPanel;
}
public void addControls(ActionEvent actionEvent) {
Application application = FacesContext.getCurrentInstance()
.getApplication();
List<UIComponent> children = controlPanel.getChildren();
children.clear();
for (int count = 0; count < numControls; count++) {
HtmlOutputText output = (HtmlOutputText) application
.createComponent(HtmlOutputText.COMPONENT_TYPE);
output.setValue(" " + count + " ");
output.setStyle("color: blue");
children.add(output);
}
}
public String goodbye() {
return "success";
}
}
Clean Deployment : The application is deploying itself fine on Tomcat 7. I checked the deployed package structure on &tomcat_home%/webapps and everything is in proper place as expected.
But when i run the application on a browser I get the following error :
HTTP Status 500 - /JSP/hello.jsp (line: 37, column: 2) A literal value was specified for attribute actionListener that is defined as a deferred method with a return type of void. JSP.2.3.4 does not permit literal values in this case
type Exception report
message /JSP/hello.jsp (line: 37, column: 2) A literal value was specified for attribute actionListener that is defined as a deferred method with a return type of void. JSP.2.3.4 does not permit literal values in this case
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: /JSP/hello.jsp (line: 37, column: 2) A literal value was specified for attribute actionListener that is defined as a deferred method with a return type of void. JSP.2.3.4 does not permit literal values in this case
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:42)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:408)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:149)
org.apache.jasper.compiler.Validator$ValidateVisitor.checkXmlAttributes(Validator.java:1151)
org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:875)
org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1539)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2376)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2428)
org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:894)
org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1539)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2376)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2428)
org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:894)
org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1539)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2376)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2428)
org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2434)
org.apache.jasper.compiler.Node$Root.accept(Node.java:475)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2376)
org.apache.jasper.compiler.Validator.validateExDirectives(Validator.java:1795)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:217)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:373)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:646)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
I am not finding a suitable one stop solution for this issue.
It is the EL used on the line actionListener="#{helloBean.addControls} which is raising the complications.
Please let me know the solution.
回答1:
Change inside your web.xml
<webapp>
into
<web-app version="2.5"
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-app_2_5.xsd">
in addition to the above try adding
to your web-app...
like this
<web-app version="2.5"
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-app_2_5.xsd"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID">
来源：https://stackoverflow.com/questions/13858017/jsp-el-conflict-with-jsf-1-x-actionlistener