如何解決找不到方法HttpServletRequest.getServletContext() ---- NoSuchMethodError

報錯

java.lang.NoSuchMethodError:

javax.servlet.http.HttpServletRequest.getServletContext()Ljavax/servlet/ServletContext;

 

造成問題的原因

 

ServletRequest的getServletContext方法是Servlet3.0添加的，這個可以看一下官方文檔

http://docs.oracle.com/javaee/6/api/javax/servlet/ServletRequest.html#getServletContext()

而Tomcat6只支持到Servlet2.5看它的官方文檔可以知道，要用J2EE6的話得換成Tomcat7

http://tomcat.apache.org/tomcat-6.0-doc/index.html

舊版本需要先用request拿到HttpSession或者通過

 

修改方法

//String contextPath = req.getServletContext().getContextPath(); // 
        /**
         * ServletRequest的getServletContext方法是Servlet3.0添加的，這個可以看一下官方文檔
            http://docs.oracle.com/javaee/6/api/javax/servlet/ServletRequest.html#getServletContext()
            而Tomcat6只支持到Servlet2.5看它的官方文檔可以知道，要用J2EE6的話得換成Tomcat7
         * 
         * */        
        String contextPath = null;
        if(req instanceof HttpServletRequest){
            HttpServletRequest hreq = (HttpServletRequest) req;
            contextPath = hreq.getSession().getServletContext().getContextPath();
        }