Servlet JSP之 ServletConfig对象

ServletConfig对象有四个方法。

getInitParameter、 getInitParameterNames、 getServletName

（1）getInitParameter、 getInitParameterNames用于获取Web.xml中的参数名、参数值。

（2）getServletName 获取 Web.xml中的 Servlet-name。

实例

下面是Web.xml的文件内容：

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns=&<strong style="color:transparent">来源gaodai#ma#com搞@代~码$网</strong>quot;http://xmlns.jcp.org/xml/ns/javaee"         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"         version="4.0"><servlet>        <servlet-name>TestServletConfig</servlet-name>        <servlet-class>com.djun.serveleMapping.TestServletConfig</servlet-class>         <!--配置Servlet的初始化参数-->        <!-- 如何获取初始化的参数？            1、getInitParameter(String name)            Returns a String containing the value of the named initialization parameter,            or null if the parameter does not exist.            2、 getInitParameterNames()            Returns the names of the servlet's initialization parameters as an Enumeration of String objects,            or an empty Enumeration if the servlet has no initialization parameters.        -->        <init-param>            <param-name>username</param-name>            <param-value>admin</param-value>        </init-param>         <init-param>            <param-name>passworld</param-name>            <param-value>admin</param-value>        </init-param>        <!--         指定Servlet JSP被创建的时机         若数值 a<0,则仅在第一次的时候被创建。         若 a>=0 , 则在当前应用被Servlet容器加载时创建实例         数值越小越早被创建      -->        <load-on-startup>1</load-on-startup>    </servlet>     <servlet-mapping>        <servlet-name>TestServletConfig</servlet-name>        <!--只要后缀为html的文件都由该类处理-->        <url-pattern>/servletConfig</url-pattern>    </servlet-mapping></web-app>

import javax.servlet.*;import java.io.IOException;import java.util.Enumeration; public class TestServletConfig implements Servlet {    @Override    public void init(ServletConfig servletConfig) throws ServletException {        System.out.println("Init TestServletConfig...");        System.out.println("-----------执行getInitParameter--------");        String username = servletConfig.getInitParameter("username");        String passworld = servletConfig.getInitParameter("passworld");        System.out.println("username: " + username+"\n"+"password : "+passworld);         System.out.println("----------执行getInitParameterNames------");        Enumeration<String> names = servletConfig.getInitParameterNames();         while(names.hasMoreElements()){            String name = names.nextElement();            String value = servletConfig.getInitParameter(name);            System.out.println("username: " + name+"\n"+"password : "+value);        }        String servletName = servletConfig.getServletName();        System.out.println(servletName);    }     @Override    public ServletConfig getServletConfig() {        return null;    }     @Override    public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {        System.out.println("TestServletConfig....");    }     @Override    public String getServletInfo() {        return null;    }     @Override    public void destroy() {     }}

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