Wie erstelle ich mysql-Datenbank in TomCat für eine Android-App?

Question

Kann mir jemand in die Richtung zeigen, wie man eine MYSQL-Datenbank erstellt und sie in einem Tomcat-Webserver hat? Diese Datenbank wird für eine Android-Anwendung verwendet. Danke.

Answer 1

Dies ist eine Beispielanmeldung in Android, die eine MySQL-Datenbank verwendet. Um eine Verbindung zur MySQL-Datenbank von einem Android-Gerät/Emulator herzustellen, sende ich eine HTTP-Anfrage an ein Servlet von der Anwendung, die über JSON verarbeitet wird. Es gibt also zwei verschiedene Projekte hier. Abfrage erstellen MySQL-Datenbank

CREATE TABLE `users` (
    `id` int(10) unsigned NOT NULL auto_increment, 
    `uname` varchar(45) NOT NULL, 
    `password` varchar(45) NOT NULL, 
    PRIMARY KEY (`id`) 
); 

INSERT INTO `users` (`id`,`uname`,`password`) VALUES 
(1,'admin','123'); 

Hinweis: Sie müssen die folgenden zwei Gläser müssen die Projekte Klassenpfad platziert werden. 1. json-simple-1.1.1.jar 2. mysql-connector-java-5.xxx-bin.jar LoginServlet.java

import dbConnection.DBConnectionHandler; 
import java.io.IOException; 
import javax.servlet.ServletException; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
import java.sql.*; 
import java.util.Enumeration; 
import org.json.simple.JSONObject; 

public class LoginServlet extends HttpServlet { 

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code."> 
    /** 
    * 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 { 
     //response.setContentType("text/html;charset=UTF-8"); 
     JSONObject json = new JSONObject(); 


     //ObjectOutputStream out = new ObjectOutputStream(response.getOutputStream()); 
     Enumeration paramNames = request.getParameterNames(); 
     String params[] = new String[2]; 
     int i = 0; 
     while (paramNames.hasMoreElements()) { 
      String paramName = (String) paramNames.nextElement(); 

      //System.out.println(paramName); 
      String[] paramValues = request.getParameterValues(paramName); 
      params[i] = paramValues[0]; 

      //System.out.println(params[i]); 
      i++; 

     } 

     String sql = "SELECT uname, password FROM users where uname=? and password=?"; 
     Connection con = DBConnectionHandler.getConnection(); 

     try { 
      PreparedStatement ps = con.prepareStatement(sql); 
      ps.setString(1, params[0]); 
      ps.setString(2, params[1]); 
      ResultSet rs = ps.executeQuery(); 
      if (rs.next()) { 
       json.put("info", "success"); 
      } else { 
       json.put("info", "fail"); 
      } 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
     //System.out.println(json); 
     response.setContentType("application/json"); 
     response.setCharacterEncoding("UTF-8"); 
     response.getWriter().write(json.toString()); 
    } 

    /** 
    * 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 { 
     doGet(request, response); 
    } 
} 

DBConnectionHandler.java

public class DBConnectionHandler { 

    Connection con = null; 

    public static Connection getConnection() { 
     Connection con = null; 
     try { 
      Class.forName("com.mysql.jdbc.Driver");//Mysql Connection 
     } catch (ClassNotFoundException ex) { 
      Logger.getLogger(DBConnectionHandler.class.getName()).log(Level.SEVERE, null, ex); 
     } 
     try { 
      con = DriverManager.getConnection("jdbc:mysql://localhost:3306/dbname", "root", "pass");//mysql database 

     } catch (SQLException ex) { 
      Logger.getLogger(DBConnectionHandler.class.getName()).log(Level.SEVERE, null, ex); 
     } 
     return con; 
    } 

} 

activity_main .xml

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"> 

    <LinearLayout 
     android:layout_width="fill_parent" 
     android:layout_height="fill_parent" 
     android:orientation="vertical" 
     android:padding="10dip" > 
     <!-- View Title Label --> 
     <TextView 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:layout_marginBottom="10dip" 
      android:text="LOGIN" 
      android:textSize="25dip" 
      android:textStyle="bold" /> 
     <!-- User Name Label --> 
     <TextView 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:text="User Name" /> 
     <!-- User Name TextField --> 
     <EditText 
      android:id="@+id/txtUser" 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" /> 

     <!-- Password Label --> 
     <TextView 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:layout_marginTop="15dip" 
      android:text="Password" /> 
     <!-- Password TextField --> 
     <EditText 
      android:id="@+id/txtPass" 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:password="true" /> 

     <!-- Login Button -->  
     <Button 
      android:id="@+id/button1" 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:layout_marginTop="20dip" 
      android:text="Login" /> 
     </LinearLayout> 

</ScrollView> 

Insgesamt Tutorial und Source-Code finden Sie hier http://www.javaknowledge.info/sample-login-app-in-android-using-servlet-and-json-parsing/