package servlet;import java.io.IOException;import java.io.InputStream;import java.util.Enumeration;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 HelloServlet extends HttpServlet {    /**     * Constructor of the object.     */    public HelloServlet() {        super();        System.out.println("constructor");    }    public void init(ServletConfig servletconfig) throws ServletException {        // ServletConfig常用方法        String v = servletconfig.getInitParameter("user:");        // String v = this.getInitParameter("user:");        // //也行，因为HttpServlet是ServletConfig的实现类，所以可以用this调用该方法        System.out.println("method1:" + v);        System.out.println("init");        // Enumeration<String> en = this.getInitParameterNames();        Enumeration<String> en = servletconfig.getInitParameterNames();        while (en.hasMoreElements()) {            String names = en.nextElement();            String values = servletconfig.getInitParameter(names);            System.out.println(names + "-->" + values);        }        System.out.println("");        // ServletContext常用方法        ServletContext sct = servletconfig.getServletContext();        String svalue = sct.getInitParameter("driver");        System.out.println(svalue);        // 获取当前文件在web服务器上的绝对路径        String str = sct.getRealPath("/file1.txt");        System.out.println(str);        // 获取当前web应用名称        String conp = sct.getContextPath();        System.out.println(conp);        try {            InputStream is = sct                    .getResourceAsStream("/WEB-INF/classes/xml.properties"); // 路径是相对当前web应用的路径            System.out.println(is);        } catch (Exception ex) {            ex.printStackTrace();        }    }    public void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        System.out.println("doGet");    }    public void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        System.out.println("dopost");    }    public void destroy() {        super.destroy(); // Just puts "destroy" string in log        // Put your code here        System.out.println("destroy");    }}

<?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">    <context-param>           <param-name>driver</param-name>           <param-value>jdbc.odbc</param-value>    </context-param>    <servlet>        <servlet-name>HelloServlet</servlet-name>        <servlet-class>servlet.HelloServlet</servlet-class>        <!--设置局部初始化参数  -->        <init-param>            <param-name>user:</param-name>            <param-value>wuyj</param-value>        </init-param>        <init-param>            <param-name>password:</param-name>            <param-value>123</param-value>        </init-param>        <load-on-startup>3</load-on-startup>    </servlet>    <servlet-mapping>        <servlet-name>HelloServlet</servlet-name>        <url-pattern>/servlet/HelloServlet</url-pattern>    </servlet-mapping>    <welcome-file-list>        <welcome-file>index.jsp</welcome-file>    </welcome-file-list></web-app>