简单的可上网微信小程序创建和布局——课程五

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package cn.edu.hit;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author dell
 */
public class LoginServlet extends HttpServlet{
    
    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException{
        response.setContentType("text/html.charset=UTF-8");//设置源文本类型
        try(PrintWriter out =response.getWriter()){//捕获异常
         String username=request.getParameter("username");//获取参数
        String password=request.getParameter("password");//获取参数
         Class.forName("com.mysql.jdbc.Driver");//启动驱动
        Connection con = DriverManager.getConnection("jdbc:mysql:你的服务器地址。","你的服务器登陆名","你的服务器密码");//建立一个连接
        Statement stmt = con.createStatement();//描述符。
        ResultSet rs=stmt.executeQuery("select * from users where username=‘"+username+"‘and password=‘"+password+"‘");//在数据库查找。
                if(rs.next()){//假如找到了
                    out.print("success");//打印成功。
                }
                else{//不然就打印fail
                    out.print("fail!");
                }
                con.close();//关闭连接。
        }
        catch(Exception e)//捕获异常的catch框
        {
            e.printStackTrace();
        }
    }
     
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}