JavaWeb-利用Enumeration获取初始化参数
2015-10-16 10:32
351 查看
JavaWeb-利用Enumeration获取初始化参数
要点- getInitParameter()方法:public java.lang.String getInitParameter(java.lang.String name)
- getInitParameterNames()方法:public java.util.Enumeration getInitParameterNames()
getInitParameter()方法概述:public java.lang.String getInitParameter(java.lang.String name)
返回上下文定义的变量的值,如果变量不存在,返回null。
见ServletConfig.getInitParameter(java.lang.String)。
getInitParameterNames()方法概述:public java.util.Enumeration getInitParameterNames()
返回上下文定义的所以变量的枚举函数,如果空则返回空枚举函数。
首先在web.xml设置全局参数:
[code]<?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"> <!-- 全局参数 --> <context-param> <param-name>user</param-name> <param-value>root</param-value> </context-param> <context-param> <param-name>password</param-name> <param-value>xieth123456</param-value> </context-param> <context-param> <param-name>adress</param-name> <param-value>china</param-value> </context-param> <!-- 全局参数 --> <servlet> <servlet-name>HitServlet</servlet-name> <servlet-class>com.org.web.HitWebDemo</servlet-class> </servlet> <servlet-mapping> <servlet-name>HitServlet</servlet-name> <url-pattern>/Hit</url-pattern> </servlet-mapping> <servlet> <servlet-name>EServlet</servlet-name> <servlet-class>com.org.web.EnumDemo</servlet-class> </servlet> <servlet-mapping> <servlet-name>EServlet</servlet-name> <url-pattern>/Enum</url-pattern> </servlet-mapping> </web-app>
EnumDemo.java
[code]package com.org.web; import java.io.IOException; import java.io.PrintWriter; import java.util.*; import javax.servlet.ServletConfig; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class EnumDemo extends HttpServlet { private List<Map<String, String>> list = new ArrayList<>(); @Override public void init(ServletConfig config) throws ServletException { ServletContext servletContext = config.getServletContext(); Enumeration<String> enumeration = servletContext.getInitParameterNames(); while (enumeration.hasMoreElements()) { Map<String, String> map = new HashMap<>(); String name = enumeration.nextElement(); map.put("name", name); map.put("value", servletContext.getInitParameter(name)); list.add(map); } } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html;charset=gb2312"); PrintWriter out = resp.getWriter(); Iterator it = list.iterator(); while (it.hasNext()) { Map<String, String> map = (Map<String, String>) it.next(); out.println("<h3>" + map.get("name") + ":" + map.get("value") + "</h3>"); } } }
运行结果:
相关文章推荐
- 用eclipse创建java web工程
- Imagga 图像识别技术API调用方法
- Mac系统下的Eclipse代码联想功能开启代码联想功能
- 在AWS EMR上运行Map Reduce的Java示例程序 及 操作小计
- struts2的namespace
- eclipse 方便快捷安装svn
- Eclipse使用技巧
- 从高版本JDK换成低版本JDK报错Unsupported major.minor version 52.0
- 基于Spring2.5.6搭建技术开发框架
- Java学习之二-Java反射机制
- Java IO
- 基于Netbeans的PHPUnit单元测试环境搭建
- eclipse中的maven web项目报错:org/codehaus/plexus/archiver/jar/JarArchiver
- ajax + struts2 return 404 Code
- Stanford NLP自然语序处理demo,附maven dependency
- java编程IO简单回顾和学习
- eclipse maven plugin 插件 安装 和 配置
- maven jdk 版本配置
- Java用itext操作PDF
- MyEclipse在Java文件中设置作者、日期