ServletContext全局变量初始化

时间:2022-04-11 20:11:30

Java部分

package com.servlet;

import java.io.IOException;
import java.io.PrintWriter; import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse; public class ServletContext extends HttpServlet { private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("utf-8");
response.setContentType("text/html"); javax.servlet.ServletContext servletContext=getServletConfig().getServletContext();
String uploadFolder=servletContext.getInitParameter("upload folder");
String allowedFileType=servletContext.getInitParameter("allowed file type"); PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>"); out.println("上传文件夹××××××××××××"+uploadFolder);
out.println("<br/>上传文件类型××××××××××××"+allowedFileType); out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
}

  web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name> <context-param>
<param-name>upload folder</param-name>
<param-value>attachment</param-value>
</context-param>
<context-param>
<param-name>allowed file type</param-name>
<param-value>.gif,.jpg,.bmp</param-value>
</context-param> <servlet>
<servlet-name>ServletContext</servlet-name>
<servlet-class>com.servlet.ServletContext</servlet-class>
</servlet> <servlet-mapping>
<servlet-name>ServletContext</servlet-name>
<url-pattern>/servlet/ServletContext</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>