问题描述:

建立了web工程,配置pom.xml,web.xml,编写controller类,在spring-mvc-servlet.xml文件中指定开启注解和扫描的包位置<mvc:annotation-driven /> <context:component-scan base-package="controller" />.打开tomcat,在浏览器中访问,提示404错误

问题分析:

一. 确定配置文件是否配置正确(springmvc的配置文件,web.xml和pom.xml基本不会配置出错)

因为提示的是404错误,可以确定正确加载了配置文件,处于排查需要,还是检查了配置文件的配置问题.
a) 放在WEB-INF/文件夹下,名称为spring-mvc-servlet.xml,不需要在web.xml中配置,系统自动读取
b) 放在WEB-INF/文件夹下,名称为自定义,或者放在src/main/resource文件夹下,需要在web.xml中配置,
配置代码如下:

    <servlet>  <servlet-name>dispatch</servlet>  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>  <init-param>  <param-name>contextConfigLocation</param-name>  <param-value>/WEB-INF/applicationContext.xml</param-value>  </init-param>  </servlet>  <servlet-mapping>  <servlet-name>dispatch</servlet-name>  <servlet-pattern>*.*</servlet-pattern>  </servlet-mapping>  

二. 确定maven 依赖正确配置
a) 一般使用两个依赖就能使用注解配置springmvc项目,并能正常运行
pom中的依赖如下:

    <properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><spring.version>4.2.6.RELEASE</spring.version><hibernate.version>4.3.8.Final</hibernate.version></properties><dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>3.8.1</version><scope>test</scope></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>${spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-web</artifactId><version>${spring.version}</version></dependency></dependencies>

b) 我使用spring+springmvc+hibernate的搭配,pom依赖如下:

    <properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><spring.version>4.2.6.RELEASE</spring.version><hibernate.version>4.3.8.Final</hibernate.version></properties><dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>3.8.1</version><scope>test</scope></dependency><!-- springframework 4 dependencies begin --><dependency><groupId>org.springframework</groupId><artifactId>spring-core</artifactId><version>${spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>${spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-web</artifactId><version>${spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>${spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-orm</artifactId><version>${spring.version}</version></dependency><!-- springframework 4 dependencies end --><!-- log --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.16.18</version><scope>provided</scope></dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId><version>1.7.7</version></dependency><dependency><groupId>ch.qos.logback</groupId><artifactId>logback-core</artifactId><version>1.1.3</version></dependency><dependency><groupId>ch.qos.logback</groupId><artifactId>logback-classic</artifactId><version>1.1.3</version></dependency></dependencies><dependencyManagement><dependencies><!-- hibernate 配置 begin --><dependency><groupId>org.hibernate</groupId><artifactId>hibernate-core</artifactId><version>${hibernate.version}</version></dependency><dependency><groupId>org.hibernate</groupId><artifactId>hibernate-entitymanager</artifactId><version>${hibernate.version}</version></dependency><dependency><groupId>org.hibernate.common</groupId><artifactId>hibernate-commons-annotations</artifactId><version>4.0.5.Final</version></dependency><dependency><groupId>org.hibernate.javax.persistence</groupId><artifactId>hibernate-jpa-2.1-api</artifactId><version>1.0.0.Final</version></dependency><dependency><groupId>org.hibernate</groupId><artifactId>hibernate-ehcache</artifactId><version>${hibernate.version}</version><!-- hibernate 配置 end --></dependency><!-- mysql数据库的驱动包 start --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>6.0.6</version></dependency><!-- 数据连接池 --><dependency><groupId>org.hibernate</groupId><artifactId>hibernate-c3p0</artifactId><version>${hibernate.version}</version></dependency></dependencies></dependencyManagement>

我已经依赖了a中所说的两个包,但是不能在浏览器中访问,会报404错误.

解决办法:

看了很多spring mvc的maven依赖,发现有人使用如下依赖:

     <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api --><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>3.1.0</version><scope>provided</scope></dependency> 

我在b中的pom文件中加入这个依赖,就能正常访问了,不知道什么原因.(狗屁问题,浪费了我两个小时的时间,一度怀疑人生)