使用Android和PHP将照片存储为Blob

我目前正在使用一个Android应用程序来处理图片,并将其上传到数据库。 该应用程序首先使用设备的摄像头,然后将生成的位图发送到AsyncTask,该任务将调用PHP API以将图像作为mediumBLOB和附加数据(int和String)更新数据库。

AsyncTask将位图编码为字符串,并将所有需要的数据作为POST请求发送到PHP页面。

然后PHP页面收集数据,将字符串转换为BLOB图像,并在mysqli请求中使用它们在数据库表中插入新行。

更新时间: 感谢您的反馈。我更改了PHP代码,以使用绑定变量。 尽管如此,当我将图像设置为参数时,请求会生成一个带有空BLOB的新表行。 我知道通常的方法是将图像存储在其他地方,并在数据库中使用它们的名称/url;但在我的例子中,使用blob是一项要求。

以下是AsyncTask的Android代码:

public class DBTaskImageSending extends AsyncTask<String, Void, Void>
{
    static final String TAG = "asyncSend";

    private final String PARAMETER_PLACE = "location";
    private final String PARAMETER_IMAGE = "image";
    private final String PARAMETER_COMMENT = "comment";
    private final String PARAMETER_OWNER = "owner";

    Context mCContext;
    UploadActivity mUAMain;

    //The PHP page address :
    String mURLAdress;

    //Data to send to the PHP page :
    String mComment;
    int mID_Photographer;
    int mID_Event;
    String mImage; //The image in its final conversion before sending it.

    public DBTaskImageSending(String url, UploadActivity ua, Context c, Bitmap img, String comment, int place, int owner)
    {
        this.mURLAdress = url;
        this.mCContext = c;
        this.mUAMain = ua;

        this.mComment = comment;
        this.mID_Event = place;
        this.mID_Photographer = owner;
        this.mImage = conv_Image_String(img);
    }

    @Override
    protected void onPreExecute()
    {
        super.onPreExecute();
        Log.i(TAG, "Request sent to "+mURLAdress);
    }

    @Override
    protected void onPostExecute(Void result)
    {
        Log.i(TAG,"__________________________________________________");
        super.onPostExecute(result);
    }

    @Override
    protected Void doInBackground(String... strings)
    {
        try
        {
            sendImage(mURLAdress);
            Log.i(TAG, "Object sent !");
        }
        catch (IOException ioe)
        {
            Log.i(TAG, "Sending failed.");
        }
        return null;
    }

    public void sendImage(String url) throws IOException
    {
        //Loading the POST data :
        String mSCryptedData = URLEncoder.encode(PARAMETER_PLACE, "UTF-8")
                + "=" + URLEncoder.encode(Integer.toString(mID_Event), "UTF-8");
        //----- owner ID :
        mSCryptedData += "&" + URLEncoder.encode(PARAMETER_OWNER, "UTF-8")
                + "=" + URLEncoder.encode(Integer.toString(mID_Photographer), "UTF-8");
        //----- Image comments :
        mSCryptedData += "&" + URLEncoder.encode(PARAMETER_COMMENT, "UTF-8")
                + "=" + URLEncoder.encode(mComment, "UTF-8");
        //----- the image itself :
        mSCryptedData += "&" + URLEncoder.encode(PARAMETER_IMAGE, "UTF-8")
                + "=" + URLEncoder.encode(mImage,"UTF-8");//*/

        ContentValues mCV = new ContentValues();
        mCV.put(PARAMETER_PLACE,mID_Event);
        mCV.put(PARAMETER_OWNER,mID_Photographer);
        mCV.put(PARAMETER_COMMENT,mComment);
        mCV.put(PARAMETER_IMAGE,mImage);

        try {
            //Eestablishing connection :
            final HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setReadTimeout(5000); // milliseconds
            conn.setConnectTimeout(5000); // milliseconds

            //Setting up and sending the data :
            conn.setDoOutput(true);
            OutputStreamWriter mOSW = new OutputStreamWriter(conn.getOutputStream());
            mOSW.write(mSDataCryptee);
            mOSW.flush();

            //Gathering the server's response:
            readResponse(conn.getInputStream());
        }
        catch (Exception e)
        {
            Log.i(TAG,e.getCause().toString());
        }
    }

    private void readResponse(InputStream pISBuilder) throws IOException
    {
        Log.i(TAG,"readR : Entering...");
        BufferedReader mBR = new BufferedReader(new InputStreamReader(pISBuilder));
        String ligne;

        Log.i(TAG,"readR : Starting to read");
        //Gathering the PHP response :
        while ((ligne = mBR.readLine()) != null)
        {
            Log.i(TAG,ligne);
        }
    }

    //* Function to convert the Bitmap to String :
    private String conv_Image_String(Bitmap imgOrigin)
    {
        if (imgOrigin != null)
        {
            //The image is first converted to byte[] (or Blob), before being encoded to String.
            ByteArrayOutputStream mBOS = new ByteArrayOutputStream();
            imgOrigin.compress(Bitmap.CompressFormat.PNG,10, mBOS);
            byte[] mBytImg = mBOS.toByteArray();

            String mStrImg = Base64.encodeToString(mBytImg, Base64.DEFAULT);
            return mStrImg;
        }
        else
        {
            return null;
        }
    }//*/

}

我重新编写了PHP代码,下面是新版本:

<?php
if ((isset($_POST['location']) AND isset($_POST['owner'])) AND (isset($_POST['comment']) AND isset($_POST['image']))) {
    $location = $_POST['location'];
    $comment = $_POST['comment'];
    $owner = $_POST['owner'];
    $image = base64_decode($_POST['image']);

    $image_b = imagecreatefromstring($image);

    //*
    if ($image_b == false) {
        echo "error_image";
    }
    else {

        $image_temp = imagegd($image_b, 'tmp');
        $image_f = fopen('tmp',"r");
        $image_blob = fread($image_f,filesize('tmp'));

        sendData ($location,$comment,$owner,$image_blob);
    }
}
else {
    echo "error_parameters";
}

function sendData($p_location,$p_comment,$p_owner,$p_image){
    $conn = mysqli_connect("localhost", "****", "****", "**DBName**", "3306");
    if (!$conn) {
        die('Could not connect to MySQL: ' . mysqli_connect_error());
    }
    else {
        mysqli_query($conn, 'SET NAMES \'utf8\'');
        $sqli = "INSERT INTO bar_a_image_test.Photo(
            ID_Localisation_Photo,
            ID_Photographe,
            Date_Photo,
            Ecartee,
            Commentaire_Photo,
            Image_Photo)
        VALUES
            ( ? , ? , NULL, 0, ?, ? )";

        if ($stmt = $conn->prepare($sqli));
        {
            $stmt->bind_param("iisb",$p_location, $p_owner, $p_comment, $p_image);
            $stmt->execute();
        }
        $conn->close();
    }
}
?>

现在的新问题是,查询加载数据库中的所有数据,除了图像。它只在新行中记录一个空BLOB。 我正在寻找一种有效地将图像(编码为字符串)转换为BLOB的方法。 正如我之前提到的,我必须使用blob,尽管外部存储更加频繁。