JAVA WEB项目异常处理提示页

最近一直感到困惑，为啥我的后台报错就赤果果的将程序中的错误打印在页面，这样在项目上线后，如果遇到500，java.lang.Exception等错误时，会提示很尴尬的信息

感谢http://blog.csdn.net/zhangxin09/article/details/50644694

1.web.xml中配置

<error-page>
<exception-type>java.lang.Exception</exception-type>
<location>/error/error_500.jsp</location>
</error-page>
<error-page>
<error-code>403</error-code>
<location>/error/error_404.jsp</location>
</error-page>
<error-page>
<error-code>404</error-code>
<location>/error/error_404.jsp</location>
</error-page>
<error-page>
<error-code>500</error-code>
<location>/error/error_500.jsp</location>
</error-page>
<error-page>
<error-code>503</error-code>
<location>/error/error_500.jsp</location>
</error-page>
<error-page>
<exception-type>java.lang.NullPointException</exception-type>
<location>/error/error_500.jsp</location>
</error-page>

2.在util页面中COPY
http://blog.csdn.net/zhangxin09/article/details/50644694 中的写法如下

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@page import="java.io.*"%>
<%@page import="java.util.*"%>
<%!
class ErrorHandler {

// 全部内容先写到内存，然后分别从两个输出流再输出到页面和文件
private ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
private PrintStream printStream = new PrintStream(byteArrayOutputStream);

/**
* 收集错误信息
* @param request
* @param exception
* @param out
*/
public ErrorHandler(HttpServletRequest request, Throwable exception, JspWriter out) {
setRequest(request);
setException(exception);
if(out != null) {
try {
out.print(byteArrayOutputStream); // 输出到网页
} catch (IOException e) {
e.printStackTrace();
}
}

log(request);

if(byteArrayOutputStream != null)
try {
byteArrayOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
if(printStream != null) printStream.close();
}

/**
*
* @param request
*/
private void setRequest(HttpServletRequest request) {
HttpSession session = request.getSession();
String username=(String)session.getAttribute("edu.yale.its.tp.cas.client.filter.user");
printStream.println();
printStream.println("用户账号：" + username);
// printStream.println("用户账号：" + request.getSession().getAttribute("userName"));
printStream.println("访问的路径: "   + getInfo(request, "javax.servlet.forward.request_uri", String.class));
printStream.println("出错页面地址: " + getInfo(request, "javax.servlet.error.request_uri", String.class));
printStream.println("错误代码: "     + getInfo(request, "javax.servlet.error.status_code", int.class));
printStream.println("异常的类型: "   + getInfo(request, "javax.servlet.error.exception_type", Class.class));
printStream.println("异常的信息: "   + getInfo(request, "javax.servlet.error.message", String.class));
printStream.println("异常servlet: "  + getInfo(request, "javax.servlet.error.servlet_name", String.class));
printStream.println();

// 另外两个对象
getInfo(request, "javax.servlet.jspException", Throwable.class);
getInfo(request, "javax.servlet.forward.jspException", Throwable.class);

Map<String, String[]> map = request.getParameterMap();

for (String key : map.keySet()) {
printStream.println("请求中的 Parameter 包括：");
printStream.println(key + "=" + request.getParameter(key));
printStream.println();
}

for (Cookie cookie : request.getCookies()){  // cookie.getValue()
printStream.println("请求中的 Cookie 包括：");
printStream.println(cookie.getName() + "=" + cookie.getValue());
printStream.println();
}

}

/**
*
* @param exception
*/
private void setException(Throwable exception) {
if (exception != null) {
printStream.println("异常信息");
printStream.println(exception.getClass() + " : " + exception.getMessage());
printStream.println();

printStream.println("堆栈信息");
exception.printStackTrace(printStream);
printStream.println();
}
}

/**
*
* @param request
*/
private void log(HttpServletRequest request) {
File dir = new File(request.getSession().getServletContext().getRealPath("/errorLog"));
if (!dir.exists()) {
dir.mkdir();
}

String timeStamp = new java.text.SimpleDateFormat("yyyyMMddhhmmssS").format(new Date());
File file = new File(dir.getAbsolutePath() + File.separatorChar + "error-" + timeStamp + ".txt");

}

/**
*
* @param request
* @param key
* @param type
* @return
*/
@SuppressWarnings("unchecked")
private <T> T getInfo(HttpServletRequest request, String key, Class<T> type){
Object obj = request.getAttribute(key);
return obj == null ? null : (T) obj;
}

}
%>

3.在error_500.jsp中引入

<%@ page language="java" pageEncoding="UTF-8" isErrorPage="true"%>
<%@ page import="java.io.PrintStream" %>
<%@ include file="../error/util.jsp"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path;
if (!path.endsWith("/")) {
basePath = basePath + "/";
}
%>
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>新版BMS支撑系统</title>
<link rel="stylesheet" type="text/css" href="<%=basePath%>css/common.css"/>
<link rel="stylesheet" type="text/css" href="<%=basePath%>css/main.css"/>
<style>
textarea {
width: 100%;
min-height: 300px;
}
</style>
<script type="text/javascript" src="<%=basePath%>js/libs/modernizr.min.js"></script>
</head>
<body>

<div class="crumb-wrap">
<div class="crumb-list"><i class="icon-font"></i><a href="#">首页</a><span class="crumb-step">></span><span class="crumb-name">系统错误提示505</span></div>
</div>
<div class="result-wrap">
<div class="config-items">
<div class="result-content">
<table width="100%" align="center" class="insert-tab">
<tbody>
<tr>
<td><img src="images/icon_cry.png"/><br/>
<h3>500或者503或者java.lang.NullPointException或者java.lang.Exception</h3>
<span style="font-size:14px;color:red;">亲爱的同事：<br/>
您好！<br/>
我们致力打造更好的运营后台，但人算不如天算，有些错误发生了，希望是在控制范围内的...<br/>
如果错误重复出现，请向咱们的码农同事反馈。<br/>
错误信息如下：<br/></span>
</td>
</tr>
<tr>
<td>
<textarea>
<%
new ErrorHandler(request, exception, out);
%>
</textarea>
</td>
</tr>
<tr>
<td>
<input type="button" value="返回" onclick="history.go(-1)" class="btn btn6">
</td>
</tr>
</tbody></table>
</div>
</div>
</div>

</body>
</html>

到此完结，看效果



一定注意<%@ page language="java" pageEncoding="UTF-8" isErrorPage="true"%>将isErrorPage="true"设置为TRUE