springmvc項目,瀏覽器報404錯誤的問題

問題描述:

建立了web工程,配置pom.xml,web.xml,編寫controller類,在spring-mvc-servlet.xml文件中指定開啟注解和掃描的包位置 <mvc:annotation-driven /> <context:component-scan base-package="controller" />.打開tomcat,在瀏覽器中訪問,提示404錯誤

問題分析:

一. 確定配置文件是否配置正確(springmvc的配置文件,web.xml和pom.xml基本不會配置出錯)

因為提示的是404錯誤,可以確定正確加載了配置文件,處於排查需要,還是檢查了配置文件的配置問題.
a) 放在WEB-INF/文件夾下,名稱為spring-mvc-servlet.xml,不需要在web.xml中配置,系統自動讀取
b) 放在WEB-INF/文件夾下,名稱為自定義,或者放在src/main/resource文件夾下,需要在web.xml中配置,
配置代碼如下:

	<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. 確定maven 依賴正確配置
a) 一般使用兩個依賴就能使用注解配置springmvc項目,並能正常運行
pom中的依賴如下:

	<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依賴如下:

	<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>${hibernate.version}</version>
				<!-- hibernate 配置 end -->
			</dependency>
			<!-- mysql數據庫的驅動包 start -->
			<dependency>
				<groupId>mysql</groupId>
				<artifactId>mysql-connector-java</artifactId>
				<version>6.0.6</version>
			</dependency>
			<!-- 數據連接池 -->
			<dependency>
				<groupId>org.hibernate</groupId>
				<artifactId>hibernate-c3p0</artifactId>
				<version>${hibernate.version}</version>
			</dependency>
		</dependencies>
	</dependencyManagement>

我已經依賴了a中所說的兩個包,但是不能在瀏覽器中訪問,會報404錯誤.

解決辦法:

看了很多spring mvc的maven依賴,發現有人使用如下依賴:

	 <!-- 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文件中加入這個依賴,就能正常訪問了,不知道什么原因.(狗屁問題,浪費了我兩個小時的時間,一度懷疑人生)