对于loader constraint violation问题的解决方案

javax.servlet.ServletException: java.lang.LinkageError: loader constraint violation: loader (instance of org/apache/jasper/servlet/JasperLoader) previously initiated loading for a different type with name "javax/servlet/http/HttpServletRequest"
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:268)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

在用maven工程构建web引用的时候引起的包冲突问题，造册灰姑娘的原因是，我在pom.xml文件中添加jar包的时候，scope的范围是compile，只需要将scope的范围改为provided，如下所示

<dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <version>3.0-alpha-1</version>
        <scope>provided</scope>
    </dependency>
    <dependency>