严重:Servlet.service() for servlet jsp threw exception java.lang

1.严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.index_jsp._jspInit(index_jsp.java:22)
at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:52)
at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:159)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:329)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342

1. error
2. 此种错误是由于jsp页面获得了一个空指针导致，即servlet传参数时有一个参数没穿过去或者传的参数和接受的参数不一致导致的

3.

原因是项目jar包和tomcat的jar包冲突了。

4处理：

<!-- 配置这一项，运行的时候不会重复导入jsp-api的jar包 -->
         <!-- servlet依赖
        <dependency>
              <groupId>javax.servlet</groupId>
              <artifactId>javax.servlet-api</artifactId>    
              <version>3.1.0</version>
              <scope>provided</scope>
        </dependency>
         -->
         <!-- jsp依赖
        <dependency>
			<groupId>javax.servlet.jsp</groupId>
			<artifactId>jsp-api</artifactId>
			<version>2.2</version>
			<scope>provided</scope>  
		</dependency>
		 -->
        <!--配置jsp jstl的支持-->
        <!--引入jstl -->
		<dependency>
		   <groupId>jstl</groupId>
		   <artifactId>jstl</artifactId>
		   <version>1.2</version>
		   <scope>provided</scope>   <!-- 配置这一项，运行的时候不会重复导入jsp-api的jar包 -->
	    </dependency>