PHP와 Android 연동하기

Centos7에 PHP 설치하기

2020/09/29 - [Web/Nginx] - Nginx에 php-fpm 설치하기 for Centos7

Nginx에 php-fpm 설치하기 for Centos7

Centos7에 MySQL 설치하기

2020/10/06 - [Web/Nginx] - Nginx에 MySQL 설치하기 for Centos7

Nginx에 MySQL 설치하기 for Centos7

 

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안드로이드 앱에서 서버로 접근하기 위해서는 보안상 앱이 직접 전송하는 것은 불가능하고

둘의 중간을 연결해주는 서버사이드 언어가 필요하다.

 

서버가 앱이 사용할 mysql 계정과 사용권한을 설정한 후

서버의 특정 파일을 이용해 DB에 데이터를 읽고 쓰고 수정할 수 있게 된다. (권한이 허용하는 안에서)

 

앱과 서버를 연결해주는 서버사이드 언어로는 PHP가 많이 사용된다.

 

 

PHP를 이용해 Android와 서버를 연동하는 방법을 알아보자.

 

 

MySQL 세팅하기

1. 먼저 mysql 계정 로그인 후 데이터베이스 및 테이블을 생성

mysql> CREATE DATABASE androidApp;
Query OK, 1 row affected (0.00 sec)

mysql> CREATE TABLE users (
    id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    userID VARCHAR(30) NOT NULL,
    password VARCHAR(30) NOT NULL,
    username VARCHAR(30) NOT NULL
)

 

2. 안드로이드 앱에서 서버로 접근할 계정을 생성한 뒤, 권한을 부여

mysql> CREATE USER 'userID'@'%' IDENTIFIED BY 'password';
Query OK, rows affected (0.00 sec)

mysql> GRANT ALL ON androidApp.* TO userID'%' IDENTIFIED BY 'password';
Query OK, rows affected (0.00 sec)

mysql> FLUSH PRIVILEGES;
Query OK, rows affected (0.00 sec)

 

3. 서버의 방화벽을 해제

$ firewall-cmd --zone=public --add-service=mysql --permanent

$ firewall-cmd --reload

 

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서버 PHP 파일 세팅하기

1. mysql에 접속할 php 파일 구성을 살펴보기

<?php
	
    $con = mysqli_connect('IP', 'userID', 'password');
    
    if(mysqli_query($con, $sql) {
    	echo "Connected";
    }
    
    mysqli_close($con);
    
?>

mysqli_connect 함수를 이용해 접속할 서버의 주소, mysql에 생성한 ID와 비밀번호를 인자값으로 주면 접속할 수 있다.

connect 이후 마지막에 mysqli_close로 종료시켜줘야 한다.

 

2. PHP로 DB에 POST로 insert 하는 파일 만들기

<?php

    $con = mysqli_connect('IP', 'userID', 'password');
    
    if(mysqli_connect_error($con){
    	echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }
    
    $userID = $_POST['userID'];
    $password = $_POST['password'];
    
    $query = "INSERT INTO users VALUES('$userID', '$password')";
    
    $result = mysqli_query($con, $query);
    
    if($result)
    	echo "INSERT success";
    else
    	echo "INSERT fail";
        
    mysqli_close($con);

?>

GET은 $_POST 이 부분을 $_GET 으로만 수정하면 된다.

 

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java 파일 수정하기

MySQL에 접속할 때는 GET 과 POST 로 접속할 수 있다.

 

1. 먼저 AndroidMainfest 파일에 인터넷 사용 퍼미션을 허가

<uses-permission android:name="android.permission.INTERNET"></uses-permission>

 

2. GET 매서드는 HttpGet, HttpClient 두 가지 클래스를 이용한다.

URL url = new URL(link);
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet();
request.setURI(new URI(link));

 

3. 두 가지 클래스를 생성한 뒤 execute 해준다.

HttpResponse response = client.execute(request);
BufferedReader in = new BufferedReader
(new InputStreamReader(response.getEntity().getContent()));

 

4. POST 매서드는 URLEncoder, URLConnection 두 가지 클래스를 이용한다.

URL url = new URL(link);
String data  = URLEncoder.encode("username", "UTF-8") + "=" + URLEncoder.encode(username, "UTF-8");
data += "&" + URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
URLConnection conn = url.openConnection(); 

 

4. class 생성 후 response를 받을 stream을 열어준다.

OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream()); 
wr.write( data ); 
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));	

 

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아이디 패스워드 조회 예시

PHP SELECT 파일

<?php
   $con=mysqli_connect("mysql10.000webhost.com","username","password","db_name");

   if (mysqli_connect_errno($con)) {
      echo "Failed to connect to MySQL: " . mysqli_connect_error();
   }
	
   $username = $_POST['username'];
   $password = $_POST['password'];
   $result = mysqli_query($con,"SELECT Role FROM table1 where 
   Username='$username' and Password='$password'");
   $row = mysqli_fetch_array($result);
   $data = $row[0];

   if($data){
      echo $data;
   }
	
   mysqli_close($con);
?>

 

src/com.example.phpmysql/MainActivity.java

package com.example.phpmysql;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

   private EditText usernameField,passwordField;
   private TextView status,role,method;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      usernameField = (EditText)findViewById(R.id.editText1);
      passwordField = (EditText)findViewById(R.id.editText2);

      status = (TextView)findViewById(R.id.textView6);
      role = (TextView)findViewById(R.id.textView7);
      method = (TextView)findViewById(R.id.textView9);
   }



   public void login(View view){
      String username = usernameField.getText().toString();
      String password = passwordField.getText().toString();
      method.setText("Get Method");
      new SigninActivity(this,status,role,0).execute(username,password);

   }

   public void loginPost(View view){
      String username = usernameField.getText().toString();
      String password = passwordField.getText().toString();
      method.setText("Post Method");
      new SigninActivity(this,status,role,1).execute(username,password);
   }
}

 

src/com.example.phpmysql/SigninActivity.java

package com.example.phpmysql;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.content.Context;
import android.os.AsyncTask;
import android.widget.TextView;

public class SigninActivity  extends AsyncTask{
   private TextView statusField,roleField;
   private Context context;
   private int byGetOrPost = 0;

   //flag 0 means get and 1 means post.(By default it is get.)
   public SigninActivity(Context context,TextView statusField,TextView roleField,int flag) {
      this.context = context;
      this.statusField = statusField;
      this.roleField = roleField;
      byGetOrPost = flag;
   }

   protected void onPreExecute(){
   }

   @Override
   protected String doInBackground(String... arg0) {
      if(byGetOrPost == 0){ //means by Get Method

         try{
            String username = (String)arg0[0];
            String password = (String)arg0[1];
            String link = "http://myphpmysqlweb.hostei.com/login.php?username="+username+"& password="+password;

            URL url = new URL(link);
            HttpClient client = new DefaultHttpClient();
            HttpGet request = new HttpGet();
            request.setURI(new URI(link));
            HttpResponse response = client.execute(request);
            BufferedReader in = new BufferedReader(new 
               InputStreamReader(response.getEntity().getContent()));

            StringBuffer sb = new StringBuffer("");
            String line="";

            while ((line = in.readLine()) != null) {
               sb.append(line);
               break;
            }
				
            in.close();
            return sb.toString();
         } catch(Exception e){
            return new String("Exception: " + e.getMessage());
         }
      } else{
         try{
            String username = (String)arg0[0];
            String password = (String)arg0[1];

            String link="http://myphpmysqlweb.hostei.com/loginpost.php";
            String data  = URLEncoder.encode("username", "UTF-8") + "=" +
               URLEncoder.encode(username, "UTF-8");
            data += "&" + URLEncoder.encode("password", "UTF-8") + "=" + 
               URLEncoder.encode(password, "UTF-8");

            URL url = new URL(link);
            URLConnection conn = url.openConnection();

            conn.setDoOutput(true);
            OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());

            wr.write( data );
            wr.flush();

            BufferedReader reader = new BufferedReader(new
               InputStreamReader(conn.getInputStream()));

            StringBuilder sb = new StringBuilder();
            String line = null;

            // Read Server Response
            while((line = reader.readLine()) != null) {
               sb.append(line);
               break;
            }
				
            return sb.toString();
         } catch(Exception e){
            return new String("Exception: " + e.getMessage());
         }
      }
   }

   @Override
   protected void onPostExecute(String result){
      this.statusField.setText("Login Successful");
      this.roleField.setText(result);
   }
}

 

build.gradle

android {
   useLibrary 'org.apache.http.legacy'
}

 

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:paddingBottom="@dimen/activity_vertical_margin"
   android:paddingLeft="@dimen/activity_horizontal_margin"
   android:paddingRight="@dimen/activity_horizontal_margin"
   android:paddingTop="@dimen/activity_vertical_margin"
   tools:context=".MainActivity" >

   <EditText
      android:id="@+id/editText2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignRight="@+id/editText1"
      android:layout_below="@+id/editText1"
      android:layout_marginTop="25dp"
      android:ems="10"
      android:inputType="textPassword" >
   </EditText>

   <EditText
      android:id="@+id/editText1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentRight="true"
      android:layout_alignParentTop="true"
      android:layout_marginTop="44dp"
      android:ems="10" >

   <requestFocus android:layout_width="wrap_content" />

   </EditText>

   <TextView
      android:id="@+id/textView1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBottom="@+id/editText1"
      android:layout_alignParentLeft="true"
      android:text="@string/Username" />

   <TextView
      android:id="@+id/textView3"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentTop="true"
      android:layout_centerHorizontal="true"
      android:text="@string/App"
      android:textAppearance="?android:attr/textAppearanceLarge" />

   <TextView
      android:id="@+id/textView7"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBottom="@+id/textView5"
      android:layout_alignLeft="@+id/textView6"
      android:text="@string/Role"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:textSize="10sp" />

   <TextView
      android:id="@+id/textView5"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@+id/textView6"
      android:layout_marginTop="27dp"
      android:layout_toLeftOf="@+id/editText1"
      android:text="@string/LoginRole" />
   <TextView
      android:id="@+id/textView8"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_above="@+id/textView6"
      android:layout_alignLeft="@+id/textView5"
      android:layout_marginBottom="27dp"
      android:text="@string/method" />

   <TextView
      android:id="@+id/textView4"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignLeft="@+id/textView8"
      android:layout_below="@+id/button1"
      android:layout_marginTop="86dp"
      android:text="@string/LoginStatus" />


   <TextView
      android:id="@+id/textView6"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignTop="@+id/textView4"
      android:layout_centerHorizontal="true"
      android:text="@string/Status"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:textSize="10sp" />

   <TextView
      android:id="@+id/textView9"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBottom="@+id/textView8"
      android:layout_alignLeft="@+id/textView6"
      android:text="@string/Choose"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:textSize="10sp" />

   <Button
      android:id="@+id/button2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerVertical="true"
      android:layout_toRightOf="@+id/textView6"
      android:onClick="loginPost"
      android:text="@string/LoginPost" />

   <Button
      android:id="@+id/button1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBaseline="@+id/button2"
      android:layout_alignBottom="@+id/button2"
      android:layout_alignLeft="@+id/textView2"
      android:onClick="login"
      android:text="@string/LoginGet" />

   <TextView
      android:id="@+id/textView2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBaseline="@+id/editText2"
      android:layout_alignBottom="@+id/editText2"
      android:layout_alignParentLeft="true"
      android:text="@string/Password" />

</RelativeLayout>

 

Strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

   <string name="app_name">PHPMYSQL</string>
   <string name="action_settings">Settings</string>
   <string name="hello_world">Hello world!</string>
   <string name="Username">Username</string>
   <string name="Password">Password</string>
   <string name="LoginGet">Login - Get</string>
   <string name="LoginPost">Login - Post</string>
   <string name="App">Login Application</string>
   <string name="LoginStatus">Login Status</string>
   <string name="LoginRole">Login Role</string>
   <string name="Status">Not login</string>
   <string name="Role">Not assigned</string>
   <string name="method">Login Method</string>
   <string name="Choose">Choose Method</string>
	
</resources>

 

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.example.phpmysql" >

      <uses-permission android:name="android.permission.INTERNET"/>
      <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
      
   <application
      android:allowBackup="true"
      android:icon="@drawable/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" >
      
      <activity
         android:name="com.example.phpmysql.MainActivity"
         android:label="@string/app_name" >
         
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
         
      </activity>
      
   </application>
</manifest>

 

 

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[참고문헌]

1. www.tutorialspoint.com/android/android_php_mysql.htm