路径

由于SublistServlet.java

  <servlet>
  <servlet-name>SublistServlet</servlet-name>
    <servlet-class>com.imooc.page.servlet.SublistServlet</servlet-class>
  </servlet>
  
  <servlet-mapping>
  <servlet-name>SublistServlet</servlet-name>
  <url-pattern>/servlet/sublistServlet</url-pattern>
  </servlet-mapping>

SublistServlet.java

request.getRequestDispatcher("sublistStudent.jsp").forward(request, response);

相对路径  

sublistStudent.jsp 跟 SublistServlet.java 属于同个层次

 /pager/servlet/subListStudent.jsp

request.getRequestDispatcher("/sublistStudent.jsp").forward(request, response);

SublistServlet.java

request.getRequestDispatcher("jdbcSqlStudent.jsp").forward(request, response);