运行http://localhost:8080/o2o//superadmin/listarea 时出现错误

Question

严重: Allocate exception for servlet spring-dispatcher

java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet

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Answer 1

翔仔 2018-07-29 23:08:02

同学好，不需要导入jar 你只需要配置好你的pom.xml 前提是你已经安装了maven并且与eclipse联通

参照上面截图联通后，

参照我的pom.xml,并且到上面截图的repository下面清空相应的jar并且重新update maven project

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<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.imooc</groupId>     <artifactId>o2o</artifactId>     <packaging>war</packaging>     <version>0.0.1-SNAPSHOT</version>     <name>o2o Maven Webapp</name>     <url>http://maven.apache.org</url>     <properties>         <spring.version>4.3.7.RELEASE</spring.version>     </properties>     <dependencies>         <dependency>             <groupId>junit</groupId>             <artifactId>junit</artifactId>             <version>4.12</version>             <scope>test</scope>         </dependency>         <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->         <dependency>             <groupId>ch.qos.logback</groupId>             <artifactId>logback-classic</artifactId>             <version>1.2.3</version>         </dependency>         <!-- Spring -->         <!-- 1)包含Spring 框架基本的核心工具类。Spring 其它组件要都要使用到这个包里的类，是其它组件的基本核心 -->         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-core</artifactId>             <version>${spring.version}</version>         </dependency>         <!-- 2)这个jar 文件是所有应用都要用到的，它包含访问配置文件、创建和管理bean 以及进行Inversion of Control              / Dependency Injection（IoC/DI）操作相关的所有类。如果应用只需基本的IoC/DI 支持，引入spring-core.jar              及spring-beans.jar 文件就可以了。 -->         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-beans</artifactId>             <version>${spring.version}</version>         </dependency>         <!-- 3)这个jar 文件为Spring 核心提供了大量扩展。可以找到使用Spring ApplicationContext特性时所需的全部类，JDNI              所需的全部类，instrumentation组件以及校验Validation 方面的相关类。 -->         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-context</artifactId>             <version>${spring.version}</version>         </dependency>         <!-- 4) 这个jar 文件包含对Spring 对JDBC 数据访问进行封装的所有类。 -->         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-jdbc</artifactId>             <version>${spring.version}</version>         </dependency>         <!-- 5) 为JDBC、Hibernate、JDO、JPA等提供的一致的声明式和编程式事务管理。 -->         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-tx</artifactId>             <version>${spring.version}</version>         </dependency>         <!-- 6)Spring web 包含Web应用开发时，用到Spring框架时所需的核心类，包括自动载入WebApplicationContext特性的类、Struts与JSF集成类、文件上传的支持类、Filter类和大量工具辅助类。 -->         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-web</artifactId>             <version>${spring.version}</version>         </dependency>         <!-- 7)包含SpringMVC框架相关的所有类。 -->         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-webmvc</artifactId>             <version>${spring.version}</version>         </dependency>         <!-- 8)Spring test 对JUNIT等测试框架的简单封装 -->         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-test</artifactId>             <version>${spring.version}</version>             <scope>test</scope>         </dependency>         <!-- Servlet web -->         <dependency>             <groupId>javax.servlet</groupId>             <artifactId>javax.servlet-api</artifactId>             <version>3.1.0</version>         </dependency>         <!-- json解析 -->         <dependency>             <groupId>com.fasterxml.jackson.core</groupId>             <artifactId>jackson-databind</artifactId>             <version>2.8.7</version>         </dependency>         <!-- Map工具类 对标准java Collection的扩展 spring-core.jar需commons-collections.jar -->         <dependency>             <groupId>commons-collections</groupId>             <artifactId>commons-collections</artifactId>             <version>3.2</version>         </dependency>         <!-- DAO: MyBatis -->         <dependency>             <groupId>org.mybatis</groupId>             <artifactId>mybatis</artifactId>             <version>3.4.2</version>         </dependency>         <dependency>             <groupId>org.mybatis</groupId>             <artifactId>mybatis-spring</artifactId>             <version>1.3.1</version>         </dependency>         <!-- 数据库 -->         <dependency>             <groupId>mysql</groupId>             <artifactId>mysql-connector-java</artifactId>             <version>5.1.37</version>         </dependency>         <dependency>             <groupId>c3p0</groupId>             <artifactId>c3p0</artifactId>             <version>0.9.1.2</version>         </dependency>         <!-- 图片处理 -->         <!-- https://mvnrepository.com/artifact/net.coobird/thumbnailator -->         <dependency>             <groupId>net.coobird</groupId>             <artifactId>thumbnailator</artifactId>             <version>0.4.8</version>         </dependency>         <!-- https://mvnrepository.com/artifact/com.github.penggle/kaptcha -->         <dependency>             <groupId>com.github.penggle</groupId>             <artifactId>kaptcha</artifactId>             <version>2.3.2</version>         </dependency>         <dependency>             <groupId>commons-fileupload</groupId>             <artifactId>commons-fileupload</artifactId>             <version>1.3.2</version>         </dependency>         <!-- redis客户端:Jedis -->         <dependency>             <groupId>redis.clients</groupId>             <artifactId>jedis</artifactId>             <version>2.9.0</version>         </dependency>     </dependencies>     <build>         <finalName>o2o</finalName>         <plugins>             <plugin>                 <!-- https://mvnrepository.com/artifact/org.apache.maven.plugins/maven-compiler-plugin -->                 <groupId>org.apache.maven.plugins</groupId>                 <artifactId>maven-compiler-plugin</artifactId>                 <version>3.6.1</version>                 <configuration>                     <source>1.8</source>                     <target>1.8</target>                     <encoding>UTF8</encoding>                 </configuration>             </plugin>         </plugins>     </build> </project>

这些是比较基础的问题，希望同学能去学习下maven相关的知识，这个是实战课的门槛，同时有什么问题也可以在群里请教别的同学

Answer 2

翔仔 2017-10-09 19:29:26

同学，首先正确的url地址应该是

http://localhost:8080/o2o/superadmin/listarea

不过看情况应该还是不行，因为提示是没有找到DispatcherServlet这个类，同学可以看看eclipse 你项目下面的Maven Dependencies是否有spring-webmvc这个jar包，如果没有，就跟pom.xml以及maven的配置相关

• 提问者 一劳永逸 #1

  有spring-webmvc这个jar包，也有DispatcherServlet这个类

• 翔仔 回复 提问者 一劳永逸 #2

  可是光根据同学提供的信息来看，系统运行时候确实是没有找到对应的类，同学可以对比下教程里面的配置和同学的配置，有什么不同的地方，可以试试重新build下项目

• 提问者 一劳永逸 回复 翔仔 #3

  有时还会有报404

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