基于创建Web项目运行时出错的解决方法(必看篇)

2019-11-26 11:32:46

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1、目录结构

2、各文件内容

index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %><html> <head> <title>$Title$</title> </head> <body> <form action="/Servlet" method="post">  <input type="submit" value="提交"> </form> </body></html>

web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="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_3_1.xsd"   version="3.1"> <servlet>  <servlet-name>Servlet</servlet-name>  <servlet-class>web.servlet.Servlet</servlet-class> </servlet> <servlet-mapping>  <servlet-name>Servlet</servlet-name>  <url-pattern>/Servlet</url-pattern> </servlet-mapping></web-app>

Servlet.java

package web.servlet;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;@WebServlet(name = "Servlet")public class Servlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  System.out.println("doPost()..."); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  System.out.println("doGet()..."); }}

正常运行后运行后，Server控制台会出现输出“doPost()...”字符

3、当未配置web.xml时，出现的错误提示

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="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_3_1.xsd"   version="3.1"></web-app>

解决方法：在web.xml中配置相关信息，或在Servlet.java注解中添加内容：

@WebServlet(name = "Servlet",urlPatterns = "/Servlet")

4、配置web.xml文件但未覆写doGet()和doPost()方法，或未覆写相对应的方法出现的错误提示

package web.servlet;@WebServlet(name = "Servlet")public class Servlet extends HttpServlet { }

package web.servlet;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;@WebServlet(name = "Servlet")public class Servlet extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  System.out.println("doGet()..."); }}