Resource specification not allowed here for source level below 1.7

Resource specification not allowed here for source level below 1.7

现象：tomcat能正常启动，但打开页面时，出现上面的错误。

原因：就是jsp编译的版本不对。

因为tomcat7默认jsp的编译级别为1.6。参见：Jasper 2 JSP Engine How To

解决方法：
修改conf/web.xml

 <servlet>        <servlet-name>jsp</servlet-name>        <servlet-class>org.apache.jasper.servlet.JspServlet</servlet-class>        <init-param>            <param-name>fork</param-name>            <param-value>false</param-value>        </init-param>        <init-param>            <param-name>xpoweredBy</param-name>            <param-value>false</param-value>        </init-param>          <init-param>            <param-name>compilerSourceVM</param-name>            <param-value>1.7</param-value>        </init-param>        <init-param>            <param-name>compilerTargetVM</param-name>            <param-value>1.7</param-value>        </init-param>        <load-on-startup>3</load-on-startup>    </servlet>

重启后生效。

参考：How to set Tomcat 7 source level to Java 7