WebServlet之web.xml

项目-webboort=>web-inf=>web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:jsp="http://java.sun.com/xml/ns/javaee/jsp" 
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 
version="3.0">
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>HelloWorld</servlet-name>
<servlet-class>com.bjecss.servlet.HelloWorld</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloWorld</servlet-name>
<url-pattern>/Servlet/HelloWorld</url-pattern>
</servlet-mapping>

</web-app>

==HelloWorld.jsp

package com.bjecss.servlet;


import java.io.IOException;
import java.io.PrintWriter;


import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;






public class HelloWorld extends HttpServlet {


/**
* 
*/
private static final long serialVersionUID = 1L;

@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("doGet,start");
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
PrintWriter outer = response.getWriter();
outer.println("这是我的第一个Servlet！Get方法");

}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 
System.out.println("doPost,start");
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
String type="text/html; charset=UTF-8";
response.setContentType(type);
PrintWriter outer = response.getWriter();
outer.println("<font color= 'red'>POST方法,我来了。</font>");

}

}

遇到的问题：

1.在JSP页面中设置href='/Servlet/HelloWorld'    地址链接为： http://qq:8080/Servlet/HelloWorld，无法访问404

答：JSP页面中设置href="Servlet/HelloWorld",使用相对路径。

2.com.bjecss.servlet。HelloWorld，无法找到类对象
com.bjecss.servlet.HelloWorld

解决方案：手写大小写转换有问题，可以在JAVA中自动生成出对象之后，复制粘贴。

　使用@WebServlet注解来开发Servlet

　　如果你不喜欢使用xml配置而喜欢注解的话，没关系，Servlets API同样提供了一些注解接口给你。你可以像下面的例子一样使用 @WebServlet 注解并且不需要在web.xml里为Servlet注册任何信息。容器会自动注册你的Servlet到运行环境，并且像往常一样处理它。

//导入动态包

import javax.servlet.annotation.WebServlet;

@WebServlet(name = "HelloWorld", urlPatterns = {"/HelloWorld"})
public class HelloWorld extends HttpServlet {

}