我认为这可以解决您的问题。
更改
web.xml文件后，请重新启动服务器。
web.xml
<servlet> <servlet-name>GetInitParam</servlet-name> <jsp-file>/GetInitParam.jsp</jsp-file> <init-param> <param-name>url</param-name> <param-value>hello</param-value> </init-param></servlet><servlet-mapping> <servlet-name>GetInitParam</servlet-name> <url-pattern>/GetInitParam.jsp</url-pattern> </servlet-mapping>
GetInitParam.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Example of getting init param</title></head><body><%! String url= null; public void jspInit() { ServletConfig config = getServletConfig(); url= config.getInitParameter("url"); }%><% System.out.println(url);%></body></html>更新1
如您在评论中所问
to access parameters in all jsp files。在你所有的JSP文件访问参数你必须设置
<context-param>你的
web.xml
将以下几行
web.xml
<context-param><param-name>param1</param-name><param-value>hello</param-value></context-param>
您可以通过以下方式在
jsp文件中访问此参数：
<% String param1=application.getInitParameter("param1"); System.out.println(param1);%>更新2
web.xml
<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"><context-param><param-name>param1</param-name><param-value>hello</param-value></context-param></web-app>
JSP文件
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Example of getting init param</title></head><body><% String param1=application.getInitParameter("param1"); System.out.println(param1);%></body></html>
