安卓&PHP:使用PHP将数据从Android发布到mysql数据库 [英] Android & PHP: POST-ing data from Android to mysql db using PHP

问题描述

我需要将登录/注册数据从Android应用传递到localhost上的mysql数据库.我仍在学习过程中，上个星期对此有疑问.我读了数十页的问题和回答了Stack Overflow，并尝试了所有方法，但我无法解决此问题.您能在代码中指出我的问题吗，关于php和JSON我还是新手.

I need to pass login/register data from Android app to mysql database on localhost. I'm still in learning process, and have problem with this for last week. I read dozens of pages, questions & answers on Stack Overflow and tried everything but I just can't get this to work. Can You please point me the problem in my code, I'm still newbie regarding php and JSON.

Android，活动和应用程序；AsyncTask类:

Android, Activity & AsyncTask Class:

package com.example.mario.datadrivenassignmenttwo;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

public class DbManager extends Activity {

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

public void register(View v) {
    EditText uname = (EditText) findViewById(R.id.username);
    EditText pw = (EditText) findViewById(R.id.password);

    String username = uname.getText().toString();
    System.out.println("username is: " + username);
    String password = pw.getText().toString();
    System.out.println("password is: " + password);

    Uploader task = new Uploader();
    task.execute(new String[] { "http://10.0.2.2/user_db/senddata.php", username, password });
}

public class Uploader extends AsyncTask<String, Void, String> {

    @Override
    protected String doInBackground(String... params) {

        /* 
        String response = "Finished";
        try {
            postHttpContent(params[0],params[1],params[2]);
        } catch (IOException e) {
            Log.e("error", e.toString());
        }
        return response;
        */

        try {
            String urlParam = params[0];
            String username = params[1];
            String password = params[2];
            String charset = java.nio.charset.StandardCharsets.UTF_8.name();

            String query = String.format("username=%s&password=%s", URLEncoder.encode(username, charset), URLEncoder.encode(password, charset));

            /*
            URLConnection conn = new URL(urlParam).openConnection();
            conn.setDoOutput(true);
            conn.setRequestProperty("Accept-Charset", charset);
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=" + charset);

            OutputStream output = conn.getOutputStream();
            output.write(query.getBytes(charset));
            output.flush();
            output.close();
            */

            URL url = new URL(urlParam);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setDoOutput(true);
            conn.setRequestMethod("POST");
            OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
            writer.write(query);
            writer.close();
            if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {

                System.out.println("It's ok!");
                System.out.println(query);

            } else {

                System.out.println("Error code there");

            }

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return "Finished";
    }

    @Override
    protected void onPostExecute(String result) {
        Toast.makeText(getApplicationContext(), result, Toast.LENGTH_LONG).show();
    }

}
}

还有我的PHP:

<?php
// connect to database
$hostname = "localhost";
$username = "root";
$password = "root";
$dbname = "user_db";


$link = new mysqli($hostname, $username, $password, $dbname);

// get the JSONArray the app sends
$contents = file_get_contents('php://input');

$jsonArray = json_decode($contents, true);
$jsonCount = count($jsonArray);

for ($i = 0; $i < $jsonCount; $i++) {
$item = $jsonArray[$i];
$itemUsername = utf8_decode($item['username']);
$itemPassword = utf8_decode($item['password']);
// parse the other json attributes here like the one above

$sql = "INSERT INTO users (username, password) VALUES ('$itemUsername', '$itemPassword')";

if ($link->query($sql) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $link->error;
}
}

$link->close();
?>

有很多注释的代码，这是我尝试过的所有内容，还有一些其他代码，但无济于事.我还尝试将所有连接和其余连接放到一个方法中，并在AsyncTask类中调用该方法，但同样失败.由于我不了解PHP，因此不确定问题是否出在我的Android代码或PHP文件中.

There is a lot of commented code, that's all I have tried, and some other code as well, but nothing works. I also tried putting all the connection and rest into one method and calling that method inside AsyncTask class, that failed aswell. Since I don't know PHP, I'm not sure if the problem is in my Android code or PHP file.

非常感谢.

推荐答案

我在10分钟前就知道了.我现在正在发布新代码，它可以正常工作.

I figured it out 10minutes ago. I'm posting new code now, and it works.

package com.example.korisnik.test;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class DbManager extends Activity {

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

public void register(View v) {
    EditText uname = (EditText) findViewById(R.id.username);
    EditText pw = (EditText) findViewById(R.id.password);

    String username = uname.getText().toString();
    String password = pw.getText().toString();
    System.out.println("Username is: " + username + " ,and password is: " + password);

    Uploader task = new Uploader();
    task.execute(new String[] { "http://10.0.2.2/user_db/senddata.php", username, password });
}

public class Uploader extends AsyncTask<String, Void, String> {

    @Override
    protected String doInBackground(String... params) {

        String response = null;
        try {
            response += postHttpContent(params[0],params[1],params[2]);
        } catch (IOException e) {
            System.out.println("IO Error");
            Log.e("error", e.toString());
        } catch (JSONException e) {
            System.out.println("JSON Error");
            e.printStackTrace();
        }
        return response;
    }

    @Override
    protected void onPostExecute(String result) {
        System.out.println(result);
        Toast.makeText(getApplicationContext(), result, Toast.LENGTH_LONG).show();
    }

    public String postHttpContent(String urlStr, String user, String pass) throws IOException, JSONException {
        String response = "";
        URL url = new URL(urlStr);
        HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
        httpConn.setDoOutput(true);
        httpConn.setDoInput(true);
        httpConn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
        httpConn.setRequestMethod("POST");

        JSONObject userdata = new JSONObject();
        userdata.put("username",user);
        userdata.put("password", pass);

        JSONArray data = new JSONArray();
        data.put(userdata);
        System.out.println("Array is: " + data);

        try {
            DataOutputStream localDataOutputStream = new DataOutputStream(httpConn.getOutputStream());
            localDataOutputStream.writeBytes(data.toString());
            localDataOutputStream.flush();
            localDataOutputStream.close();
            System.out.println("Data writting: " + data);
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("Data Output error");
        }

        int responseCode = httpConn.getResponseCode();
        if (responseCode == HttpURLConnection.HTTP_OK) {
            String line;
            BufferedReader br = new BufferedReader(new InputStreamReader(httpConn.getInputStream()));
            do {
                line = br.readLine();
                response += line;
            } while ((line = br.readLine()) != null);
        } else {
            response = "Error ";
            throw new IOException();
        }
        return response + " * Uploaded!";
    }
}
}

我使用JSONObject并将用户名和密码的键/值对放入其中.比我把那个JSONObject放在JSONArray中(我知道它只是一个JSONObject，我不必将它放入JSONArray中，但是由于我的PHP代码是为JSONArray设计的，并且我对PHP不太满意，所以我认为将JSONObject放入JSONArray比更改我不太了解的PHP代码要容易得多.

I used JSONObject and put key/value pairs of username and password in it. Than I put that JSONObject in JSONArray (I know it's just one JSONObject, and I didn't have to put it into JSONArray, but since my PHP code is "designed" for JSONArray, and I'm not good with PHP, I figured it's easier to put JSONObject into JSONArray, than to change PHP code which I don't understand very well.

第二个更改是使用"DataOutputStream"而不是"OutputStreamWriter".

Second change is using "DataOutputStream" instead of "OutputStreamWriter".

这篇关于安卓&PHP:使用PHP将数据从Android发布到mysql数据库的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！