servlet 第一篇
一、处理表单登录：
1、先写一个登陆页面：
1 <!DOCTYPE html> 2 <html> 3 <head> 4 <meta charset="UTF-8"> 5 <title>login</title> 6 </head> 7 <body> 8 <form action="/test/login" method="post"> 9 <table> 10 <tr> 11 <td>name</td> 12 <td><input type="text" name="userid"></td> 13 </tr> 14 <tr> 15 <td>password</td> 16 <td><input type="password" name="psw" /></td> 17 </tr> 18 <tr> 19 <td><input value="submit" type="submit"></td> 20 <td><input value="reset" type="reset"></td> 21 </tr> 22 </table> 23 </form> 24 </body> 25 </html>
2、开始servlet处理表单：
注：首先需要将servlet的api的jar包放入到webcontent的wed-info下的lib目录。
项目整体结构：
然后配置web.xml文件，：
1 //这个标签配置默认页面，可以参考另一篇 2 <welcome-file-list> 3 <welcome-file>hello.html</welcome-file> 4 </welcome-file-list> 5 //给你的servlet类命名，一般名字取与类相同的名字，下面是你的类加上包名 6 <servlet> 7 <servlet-name>LoginServlet</servlet-name> 8 <servlet-class>com.yang.LoginServlet</servlet-class> 9 </servlet> 10 //此处是给你的应用起别名，能在浏览器中访问，此处起的是login 11 <servlet-mapping> 12 <servlet-name>LoginServlet</servlet-name> 13 <url-pattern>/login</url-pattern> 14 </servlet-mapping>
2、servlet对于数据库的增删改差：
查看
1 package com.yang; 2 3 import java.io.IOException; 4 import java.io.PrintWriter; 5 import java.sql.DriverManager; 6 import java.sql.SQLException; 7 import java.sql.Connection; 8 import java.sql.*; 9 import javax.servlet.ServletException; 10 import javax.servlet.annotation.WebServlet; 11 import javax.servlet.http.HttpServlet; 12 import javax.servlet.http.HttpServletRequest; 13 import javax.servlet.http.HttpServletResponse; 14 /** 15 * Servlet implementation class Chakan 16 */ 17 @WebServlet("/Chakan") 18 public class Chakan extends HttpServlet { 19 private static final long serialVersionUID = 1L; 20 private static String CONTENT_TYPE="text/html;charset=GBK"; 21 /** 22 * @see HttpServlet#HttpServlet() 23 */ 24 public Chakan() { 25 super(); 26 // TODO Auto-generated constructor stub 27 } 28 29 public void init(){ 30 31 } 32 33 /** 34 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 35 */ 36 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 37 // TODO Auto-generated method stub 38 // System.err.println(response.getWriter().append("Served at: ").append(request.getContextPath())); 39 response.setContentType(CONTENT_TYPE); 40 PrintWriter out=response.getWriter(); 41 request.setCharacterEncoding("GBK"); 42 response.setCharacterEncoding("GBK"); 43 //连接数据库 44 try { 45 Class.forName("com.mysql.jdbc.Driver"); 46 String url="jdbc:mysql://localhost:3306/stu"; 47 String user="yang"; 48 String psw="19970817"; 49 Connection con=DriverManager.getConnection(url, user, psw); 50 Statement rs=con.createStatement(); 51 ResultSet res=rs.executeQuery("select * from student"); 52 out.println("<html>"); 53 out.print("<head><title>Chakan</title></head>"); 54 out.println("<body>"); 55 out.println("<table align='center' border='1px' cellpadding='0' colspadding='0'><tr><td>id</td><td>姓名</td><td>班级</td><td>修改</td><td>删除</td></tr>"); 56 while(res.next()){ 57 out.println("<tr><td>"+res.getString("id")+"</td><td>"+res.getString("name")+"</td><td>"+res.getShort("classgrent")+ 58 "</td><td><a href='update?id="+res.getString("id")+"'>修改</a></td><td><a href='delete?id="+res.getString("id")+ 59 "'>删除</a></td></tr>"); 60 } 61 out.println("</table></body></html>"); 62 out.flush(); 63 res.close(); 64 con.close(); 65 } catch (ClassNotFoundException | SQLException e) { 66 // TODO Auto-generated catch block 67 e.printStackTrace(); 68 } 69 out.close(); 70 } 71 72 /** 73 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 74 */ 75 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 76 // TODO Auto-generated method stub 77 doGet(request, response); 78 } 79 80 }
3、servlet工作原理：
4、servlet继承httpServlet类：
（1）dopost() 方法：
对post提交进行处理。
（2）doget() 方法：
对get提交进行处理。
5、如何将servlet项目发布到Tomcat：