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我試圖將JSF連接到數據庫。java.lang.LinkageError：加載器約束違規：解析接口方法時javax.servlet.jsp.JspApplicationContext.getExpressionFactory（）
這是文件
的web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">
<display-name>JavaServerFaces</display-name>
<resource-ref>
<description>MySQL Datasource example</description>
<res-ref-name>jdbc/mkyongdb</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
<!-- Change to "Production" when you are ready to deploy -->
<context-param>
<param-name>javax.faces.PROJECT_STAGE</param-name>
<param-value>Development</param-value>
</context-param>
<!-- Welcome page -->
<welcome-file-list>
<welcome-file>default.xhtml</welcome-file>
</welcome-file-list>
<!-- JSF mapping -->
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<!-- Map these files with JSF -->
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>/faces/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.jsf</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.faces</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.xhtml</url-pattern>
</servlet-mapping>
的context.xml
<Context>
<Resource name="jdbc/mkyongdb" auth="Container" type="javax.sql.DataSource"
maxActive="100" maxIdle="30" maxWait="10000"
username="root" password="root" driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/mkyongdb"/>
</Context>
Default.xhtml
<?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:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
>
<h:head>
<h:outputStylesheet library="css" name="table-style.css" />
</h:head>
<h:body>
<h1>JSF 2.0 + JDBC Example</h1>
<h:dataTable value="#{customer.getCustomerList()}" var="c"
styleClass="order-table"
headerClass="order-table-header"
rowClasses="order-table-odd-row,order-table-even-row"
>
<h:column>
<f:facet name="header">
Customer ID
</f:facet>
#{c.customerID}
</h:column>
<h:column>
<f:facet name="header">
Name
</f:facet>
#{c.name}
</h:column>
<h:column>
<f:facet name="header">
Address
</f:facet>
#{c.address}
</h:column>
<h:column>
<f:facet name="header">
Created Date
</f:facet>
#{c.created_date}
</h:column>
</h:dataTable>
</h:body>
</html>
CustomerBean.java
package com.mkyong;
import java.io.Serializable;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.Resource;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;
import com.mkyong.customer.model.Customer;
@ManagedBean(name="customer")
@SessionScoped
public class CustomerBean implements Serializable{
//resource injection
@Resource(name="jdbc/mkyongdb")
private DataSource ds;
//if resource inject is not support, you still can get it manually.
/*public CustomerBean(){
try {
Context ctx = new InitialContext();
ds = (DataSource)ctx.lookup("java:comp/env/jdbc/mkyongdb");
} catch (NamingException e) {
e.printStackTrace();
}
}*/
//connect to DB and get customer list
public List<Customer> getCustomerList() throws SQLException{
if(ds==null)
throw new SQLException("Can't get data source");
//get database connection
Connection con = ds.getConnection();
if(con==null)
throw new SQLException("Can't get database connection");
PreparedStatement ps
= con.prepareStatement(
"select customer_id, name, address, created_date from customer");
//get customer data from database
ResultSet result = ps.executeQuery();
List<Customer> list = new ArrayList<Customer>();
while(result.next()){
Customer cust = new Customer();
cust.setCustomerID(result.getLong("customer_id"));
cust.setName(result.getString("name"));
cust.setAddress(result.getString("address"));
cust.setCreated_date(result.getDate("created_date"));
//store all data into a List
list.add(cust);
}
return list;
}
}
Customer.java
package com.mkyong.customer.model;
import java.util.Date;
public class Customer{
public long customerID;
public String name;
public String address;
public Date created_date;
public long getCustomerID() {
return customerID;
}
public void setCustomerID(long customerID) {
this.customerID = customerID;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public Date getCreated_date() {
return created_date;
}
public void setCreated_date(Date created_date) {
this.created_date = created_date;
}
}
的pom.xml
<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.mkyong.common</groupId>
<artifactId>JavaServerFaces</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>JavaServerFaces Maven Webapp</name>
<url>http://maven.apache.org</url>
<repositories>
<repository>
<id>java.net.m2</id>
<name>java.net m2 repo</name>
<url>http://download.java.net/maven/2</url>
</repository>
</repositories>
<dependencies>
<!-- MySQL database driver -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.9</version>
</dependency>
<!-- Spring framework -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring</artifactId>
<version>2.5.6</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>2.5.6</version>
</dependency>
<dependency>
<groupId>com.sun.faces</groupId>
<artifactId>jsf-api</artifactId>
<version>2.0.0-b13</version>
</dependency>
<dependency>
<groupId>com.sun.faces</groupId>
<artifactId>jsf-impl</artifactId>
<version>2.0.0-b13</version>
</dependency>
<!-- EL 2.2 to support method parameter in EL -->
<dependency>
<groupId>org.glassfish.web</groupId>
<artifactId>el-impl</artifactId>
<version>2.2</version>
</dependency>
<!-- http://repo1.maven.org/maven2/ -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
<build>
<finalName>JavaServerFaces</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>
</plugins>
</build>
</project>
如果我跑這Tomcat7我收到以下錯誤
SEVERE: Exception sending context initialized event to listener instance of class com.sun.faces.config.ConfigureListener
java.lang.LinkageError: loader constraint violation: when resolving interface method "javax.servlet.jsp.JspApplicationContext.getExpressionFactory()Ljavax/el/ExpressionFactory;" the class loader (instance of org/apache/catalina/loader/WebappClassLoader) of the current class, com/sun/faces/config/ConfigureListener, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, javax/servlet/jsp/JspApplicationContext, have different Class objects for the type javax/el/ExpressionFactory used in the signature
at com.sun.faces.config.ConfigureListener.registerELResolverAndListenerWithJsp(ConfigureListener.java:636)
at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:226)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4701)
at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5204)
at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5199)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Jun 15, 2012 2:31:32 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart
Jun 15, 2012 2:31:32 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [/JavaServerFaces] startup failed due to previous errors
Jun 15, 2012 2:31:32 PM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [/JavaServerFaces] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Jun 15, 2012 2:31:32 PM org.apache.coyote.AbstractProtocolHandler start
INFO: Starting ProtocolHandler ["http-bio-8080"]
Jun 15, 2012 2:31:32 PM org.apache.coyote.AbstractProtocolHandler start
INFO: Starting ProtocolHandler ["ajp-bio-8009"]
Jun 15, 2012 2:31:32 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 2341 ms
任何人都可以幫我解決這個問題。
這看起來像是加載表達式語言api（el-api）的類中的衝突。任何與您的web應用程序捆綁在一起的EL jars？ –
我已經解決了這個錯誤。 el-api.jar被發現了兩次。我有一個新的錯誤。我已經更新了這個問題。請檢查它。 – bharathi
在WEB-INF/lib中是否有jsf-api和jsf-impl jar？ –