建立一个Web项目及一些错误解决办法

培训之前，先自学一波，写一个从Hello World，然后记录一下每天学习Java Web的过程；东西很多，有用的会写大量解释，希望能最终学完然后搞定这门语言吧。

1.配置tomacat：点击window-->preferences-->server-->Runtime Environments-->Add.. -->Apache Tomact 8.5（你的Tomact版本）-->选择Tomcat安装路径-->完成

并先新建一个Dynamic Web 项目

一定要先勾选这个 xml 否则还要去找配置感觉很麻烦。

2.在Java Resources 的src中建立自己java代码和正常Java项目一样可以建立impl包，Dao包等等等以后项目变大慢慢会建

3.编写一下hellojavaweb

 1 package com.etc.javaweb;
 2 
 3 import java.io.IOException;
 4 import javax.servlet.ServletException;
 5 import javax.servlet.http.HttpServlet;
 6 import javax.servlet.http.HttpServletRequest;
 7 import javax.servlet.http.HttpServletResponse;
 8 
 9 public class HelloJavaWeb extends HttpServlet {
10 private static final long serialVersionUID = 1L;
11 
12 @Override
13 protected void doGet(HttpServletRequest request, HttpServletResponse response)
14 throws ServletException, IOException {
15 response.getWriter().append("Hello JavaWeb");
16 }
17 
18 @Override
19 protected void doPost(HttpServletRequest request, HttpServletResponse response)
20 throws ServletException, IOException {
21 doGet(request, response);
22 }
23 }

4.配置xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
 3 <display-name>JavaWeb</display-name>
 4 <servlet>
 5 <servlet-name>HelloJavaWeb</servlet-name>
 6 <servlet-class>com.etc.javaweb.HelloJavaWeb</servlet-class>
 7 </servlet>
 8 
 9 <servlet-mapping>
10 <servlet-name>HelloJavaWeb</servlet-name>
11 <url-pattern>/HelloJavaWeb</url-pattern>
12 </servlet-mapping>
13 </web-app>