servlet官方（Servlet——web.xml配置）

时间2025-06-20 01:35:47分类IT科技浏览7405

导读：前言本文主要介绍Web.xml常用配置项，包括：...

前言

本文主要介绍Web.xml常用配置项，包括：

web首页的修改 Servlet通配符映射与初始化参数全局参数的设置 404,500等错误码的页面设置

首页的修改

可以在web.xml中通过<welcome-file-list>配置访问时后的默认首页

例如：

<welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.jsp</welcome-file> <welcome-file>default.htm</welcome-file> </welcome-file-list>

效果如下（默认访问到了index.html文件）：

二级页面同样适用：

Servlet通配符映射与初始化参数

我们可以通过配置通配符捕获到多个Servlet请求，例如：配置映射地址   <servlet>  <servlet-name>pattern</servlet-name> <servlet-class>pattern.PatternServlet</servlet-class> </servlet>  <servlet-mapping> <servlet-name>pattern</servlet-name> <url-pattern>/pattern/*</url-pattern> </servlet-mapping>

Servlet代码层：

package pattern; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Servlet implementation class PatternServlet */ public class PatternServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public PatternServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response) */ protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String url =request.getRequestURL().toString(); response.setContentType("text/html;charset=utf-8"); System.out.println(url); String index =url.substring(url.lastIndexOf(/)+1); response.getWriter().println(index); if("1".equals(index)) { response.getWriter().println("张三"); }else if("2".equals(index)) { response.getWriter().println("李四"); }else { response.getWriter().println("王二麻子"); } } }

结果：

全局参数的设置

看一个之前的例子：

xml中配置全局参数  <context-param> <param-name>name</param-name> <param-value>wangwei</param-value> </context-param> <context-param> <param-name>age</param-name> <param-value>24</param-value> </context-param>

servlet中获取配置的全局变量

import java.io.IOException; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Servlet implementation class ServletContext */ @WebServlet("/ServletContext") public class ServletContextSendTest extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public ServletContextSendTest() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.setContentType("text/html;charset =utf-8"); // 获取servlet配置的Web.xml中配置的全局参数name ServletContext servletContext = (ServletContext) this.getServletContext(); String name =(String) servletContext.getInitParameter("name"); response.getWriter().println(name); //自定义传入参数 servletContext.setAttribute("newName", "zhanglongzhu"); response.getWriter().println("newName 已经写入"); } }

效果：

404,500等错误码的页面设置

web.xml配置项通过error-page配置错误信息页面，示例如下：

<error-page> <error-code>404</error-code> <location>/error/404.html</location> </error-page> <error-page> <error-code>500</error-code> <location>/error/500.html</location> </error-page>

错误页面配置及结果：

404.html： <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> </head> <body> 页面资源未找到，请检查资源是否存在 </body> </html>

500.htmll：

<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> </head> <body> error,please call Adminstrator to help you </body> </html>

总结

以上就是今天的内容，包括全局参数配置，web页面配置，统配符配置捕获请求等

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