【发布时间】：2018-08-29 07:53:39
【问题描述】：
我想将我的应用程序部署到版本 7 中的 tomcat，我得到以下异常 java.lang.NoClassDefFoundError: javax/el/ELManager
但是，如果我尝试将此应用程序部署到 tomcat 版本 8，它就可以正常工作。
你有什么办法解决这个问题吗？
为什么要从tomcat 8 切换到 7？在测试环境中，repo 中是 tomcat 8，在服务器上是 tomcat7。
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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>certplatform</groupId>
<artifactId>certplatform</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.0.0</version>
<configuration>
<warSourceDirectory>WebContent</warSourceDirectory>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-
core -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>5.0.4.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-
context -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.0.4.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-
context-support -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>5.0.4.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-
webmvc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.0.4.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-web
-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>5.0.4.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.servlet/jstl -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!--https://mvnrepository.com/artifact/javax.servlet.jsp.jstl/javax.servlet.jsp.jstl-api -->
<dependency>
<groupId>javax.servlet.jsp.jstl</groupId>
<artifactId>javax.servlet.jsp.jstl-api</artifactId>
<version>1.2.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.mail/mail -->
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.5.0-b01</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-validator -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>6.0.8.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.2.15.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-entitymanager -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>5.2.15.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>42.2.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.bouncycastle/bcprov-jdk15on -->
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk15on</artifactId>
<version>1.59</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.bouncycastle/bcpkix-jdk15on -->
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcpkix-jdk15on</artifactId>
<version>1.59</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.el/javax.el-api -->
<dependency>
<groupId>javax.el</groupId>
<artifactId>javax.el-api</artifactId>
<version>3.0.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.el/el-api -->
<dependency>
<groupId>javax.el</groupId>
<artifactId>el-api</artifactId>
<version>2.2</version>
</dependency>
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
id="WebApp_ID" version="3.1">
<display-name>spring-mvc-demo</display-name>
<!-- Spring MVC Configs -->
<!-- Step 1: Configure Spring MVC Dispatcher Servlet -->
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/spring-mvc-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<!-- Step 2: Set up URL mapping for Spring MVC Dispatcher Servlet -->
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
【问题讨论】：
-
这个问题是由于这个类 javax/el/ELManager 是在 javax.el-api 版本 3.0 中引入的。 Tomcat 7 附带预捆绑的 el-api 2.2（缺少该类），它在运行时选择它，而不是你的 el-api jar。你可以访问Tomcat吗？可以升级吗？
-
感谢您的信息。升级是可能的，但我不放心，tomcat 也将在下一个操作系统更新周期更新。是的，我可以访问 tomcat。
-
最好尽可能同步您的开发/测试/生产环境。当您的测试环境具有 Tomcat 8 时，在 dev 中针对 Tomcat 8 进行开发更有意义。正如您发现 Tomcat 7 和 8 服务器带有不同的库集，因此您的代码可以针对这些不同的库集表现不同。
-
我完全同意你的看法。我天真地认为 repos 包含相同的 rpm，但我错了。有没有可能解决这个问题？
-
我在答案中总结了 cmets。
标签： java spring hibernate maven