How to use Jdbc and Servlet to operate Mysql database and write Android login server?

1. Download and install Tomcat server

2. Open eclipse and choose Java EE mode

3. Configure Servers

1. Click on the blue word in the bottom configuration box

(2) Select the corresponding versions of Apache and Tomcat in the server type

(3) Add Server runtime environment

(4) Choose the download decompressed Tomcat path

Configure Server Locations

4. Create a new dynamic web project and check GenerateWeb.xmlDeployment descriptor option.

5. mysql-connect-java-5.1.18-Bin.jarPackage import project ( http://download.csdn.net/download/sconghw/10153718)

6. Write database operation code

package com.scong.db;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.junit.Test;

import com.mysql.jdbc.Driver;

public class JdbcHello {

    private ResultSet resultSet;
    private Statement statement;
    private Connection connection;

    @Test
    public String[] loginStrings(){
    String[] nameStrings=new String[100];
    int i=0;
        //Register Driver Register mysql Driver
        try {
            DriverManager.registerDriver(new Driver());
            //Address of MySQL server jdbc: subprotocol (mysql): //server ip address: port (default 3306)/database name
            String url="jdbc:mysql://xxx.xxx.xxx.xxx:3306/login";
            //User name to access mysql server
            String username="root";
            //Password to access mysql server
            String password="123456";
            connection = DriverManager.getConnection(url,username, password);
            statement = connection.createStatement();
            String sql="select * from user;";
            resultSet = statement.executeQuery(sql);
            //Call the next() method to move the cursor to the next line
            while(resultSet.next()){
                String name=resultSet.getString(1);
                String pwString=resultSet.getString(2);
                //System.out.println(name);
                nameStrings[i]=name+"##"+pwString;
                i++;
            }
            //return nameStrings;
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{  //Close Connection
            try {
                resultSet.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            try {
                statement.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            try {
                connection.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return nameStrings;
    }

}

7. Create a new servlet class and write the server-side login code

package com.scong.servlet;

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

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 com.scong.db.JdbcHello;

/**
 * Servlet implementation class LoginTest
 */
@WebServlet("/LoginTest")
public class LoginTest extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public LoginTest() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
     *      response)
     */
    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        String usernameString = request.getParameter("username");
        String passwordString = request.getParameter("password");
        JdbcHello jdbcHello = new JdbcHello();
        String[] name = jdbcHello.loginStrings();
        PrintWriter writer = response.getWriter();
        if (usernameString == null || passwordString == null
                || usernameString.length() == 0 || passwordString.length() == 0) {
            writer.print("false!");
        } else {
            int i = 0;
            String temp = usernameString + "##" + passwordString;

            for (i = 0; i < name.length; i++) {

                if (temp.equals(name[i])) {
                    writer.print("true");                   
                    break;
                }
            }
            if (i == name.length) {
                writer.print("login false!");
            }

        }

    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
     *      response)
     */
    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

}

8. ConfigurationWeb.xmlfile

<?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" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>ServerTest</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>login</servlet-name>
    <servlet-class>com.scong.servlet.LoginTest</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>login</servlet-name>
    <url-pattern>/login</url-pattern>
  </servlet-mapping>
</web-app>