Question

我有一个包含其他JSP的JSP，使用如下代码：

<jsp:include page="include.jsp" />

我只是希望能够捕获异常，并在缺少include.jsp时向最终用户显示错误消息。如何检测或捕获丢失的资源条件？

Answer 1

我认为JSP已经暗示了objet，其中一个是异常。

tutorialspoint 的示例：

<%@ page errorPage="ShowError.jsp" %>

<html>
<head>
<title>Error Handling Example</title>
</head>
<body>
<%
    // Throw an exception to invoke the error page
    int x = 1;
    if (x == 1) {
       throw new FileNotFoundException("Error, one file is missing!!!");
    }
%>
</body>

只有您在错误页面中处理异常：

<%@ page isErrorPage="true" %>
<html>
<head>
<title>Show Error Page</title>
</head>
<body>
<h1>Opps...</h1>
<p>Sorry, an error occurred.</p>
<p>Here is the exception stack trace: </p>
<pre>
<% exception.printStackTrace(response.getWriter()); %>
</pre>
</body>
</html>

Answer 2

在原始JSP中

<%@ page errorPage="errorPage.jsp" %>
<html>
<head>
  <title>JSP exception handling</title>
</head>
<body>
    <jsp:include page="include.jsp" />
</body>
</html>

然后，在您的errorPage.jsp

中

<%@ page isErrorPage="true" %>
<html>
<head>
  <title>Display the Exception Message</title>
</head>
<body>
   <h2>errorPage.jsp</h2>
   <i>An exception has occurred. Please fix the errors. Below is the error message:</i>
   <b><%= exception %></b>
</body>
</html>

积分 ：从本教程中摘录的示例：http://beginnersbook.com/2013/11/jsp-exception-handling/

Answer 3

您应该使用java.io.File检查文件是否丢失。

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@page import="java.io.*"%>
<%@page import="java.io.File.*"%>
<%
    String filename = "kpisrc/getNowTime2.jsp";

    File f = new File(filename);
    if(f.exists()){
%>
<jsp:include page="<%=filename%>" ></jsp:include>
<%
}else{
    out.print(filename + " not found.");
}

%>

或者检查文件是否存在的另一种方法 if(null == application.getResource(filename))

Answer 4

通过尝试/捕获？

<%
    try {
%>
        <jsp:include page="<%=filename%>" ></jsp:include>
<% 
    } catch(Exception e) {
%>
        the file, <%=filename%>, is missing.
<%
    } 
%>

如何捕获缺少的JSP文件异常

4 个答案: