isExit.jsp文件:
<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
<%
//该页面的作用是通过判断session中的属性值来阻止直接通过访问url绕过登陆界面的行为
if(session.getAttribute("userID") == null){
response.sendRedirect("/CoursewareSystem/login.jsp");
System.out.println("为空");
return;
}
%>
logout.jsp文件:
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
System.out.println("注销前session的ID:"+session.getId());
session.invalidate();
response.sendRedirect("/CoursewareSystem/login.jsp");
%>
在这两个文件中的sendRedirect都可以跳转,但当我在logout文件中的sendRedirect后加上return语句,则会报错
错误信息:
An error occurred at line: 9 in the jsp file: /logout.jsp
Unreachable code
6: session.invalidate();
7: response.sendRedirect("/CoursewareSystem/login.jsp");
8: return;
9: %>
10:
11:
Stacktrace:
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:92)
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330)
org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:423)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:308)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:286)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:273)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:566)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
很是不解,为什么一个加上可以,另一个加上不可以???