我通过json在php文件中获取图片编码数据。我的要求是将服务器中的图像存储在一个文件夹中，前提是每个图像都应分配一个唯一的名称。我对如何将图像存储在具有唯一名称的文件夹中产生了很多疑问，然后再次将图像的路径存储在数据库中。我已经看到了几个StackOverflow问题和在线资源，但无法清楚地了解它们。这个问题对于那些从事PHP工作的人来说似乎很简单。但作为PHP的新手和Android开发人员，我无法理解那些不太详细的答案。所以，如果有人可以帮我处理代码片段和解释，我真的很感激。我试着尽可能清楚地对问题和代码进行解释。如果有任何错误，请放轻松。以下是我尝试过的代码，并在某些方面陷入困境。提前谢谢..
<?php
$response = array();
// check for required fields
if (isset($_POST['mailid']) && isset($_POST['category']) && isset($_POST['description']) && isset($_POST['contactNum']) && isset($_POST['lookingto']) && isset($_POST['image'])) {
$usermail = $_POST['mailid'];
$category = $_POST['category'];
$description = $_POST['description'];
$contactNum = $_POST['contactNum'];
$lookingto = $_POST['lookingto'];
$base=$_POST['image'];
$binary=base64_decode($base);
$folder = "images/"; // This is my folder "images" in which pics have to be stored.
$file = fopen('storepic.jpg', 'wb'); // Here I have to give name dynamically to each pic provided that should be unique. Here I mentioned pic name as storepic.jpg, a static name.
fwrite($file, $binary);
fclose($file);
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
// mysql inserting a new row
$result = mysql_query("INSERT INTO details(usermail, category, description, contactnumber,posting_for) VALUES('$usermail', '$category', '$description','$contactNum','$lookingto')");
//// Even after giving dynamic name how can we store the path of the dynamic named image into database in the above query. For that what should be done here..
// check if row inserted or not
if ($result) {
// successfully inserted into database
$response["success"] = 1;
// echoing JSON response
echo json_encode($response);
} else {
// failed to insert row
$response["success"] = 0;
// echoing JSON response
echo json_encode($response);
}
} else {
$response["success"] = 0;
// echoing JSON response
echo json_encode($response);
}
?>
即使在其他php文件中，我也是通过select查询检索数据。我能够获得我插入的正常数据可以在Android客户端应用程序上获取它。但是又如何从路径获取图像以便以后转换为base64编码数据然后作为json响应回显..
注意： - 我的用户界面不是表单。这是一个Android UI ..
答案 0 :(得分：2)
// A very basic field validation. You should really use mysqli* or PDO*.
$fields = array(
'usermail' => 'mailid',
'category' => 'category',
'description' => 'description',
'contactNum' => 'contactNum',
'lookingto' => 'lookingto',
'binary' => 'base',
);
$okay = true;
foreach($fields as $var => $field)
{
if (!isset($_POST[$field]))
$okay = false;
if ('binary' == $var)
${$var} = base64_decode($_POST[$field]);
else
${$var} = mysql_real_escape_string($_POST[$field]);
}
if (!$okay)
{
$response["success"] = 0;
Header("Content-Type: application/json;charset=UTF-8");
die(json_encode($response));
}
$folder = "images/"; // This is my folder "images" in which pics have to be stored.
$file = tempnam($folder, 'image');
$fp = fopen($file, 'w');
fwrite($file, $binary);
fclose($file);
/* BUT WHAT IF THE FILE IS NOT JPEG?
Then you use GD library and do:
$gd = ImageCreateFromString($binary);
if (!$gd)
{
// Abort. Image was invalid.
}
// Here you can even resize it.
ImageJPEG($gd, $file, 75); // Quality 75%; useable values from 40 to 100
ImageDestroy($gd);
*/
...
$result = mysql_query("INSERT INTO details(usermail, category, description, contactnumber,posting_for) VALUES('$usermail', '$category', '$description','$contactNum','$lookingto')");
// I assume that the above table has an unique ID. So we retrieve it
$lastid = mysql_insert_id();
rename($file, $newfile = sprintf("%s/img%08d.jpg", $folder, $lastid));
上面，不需要文件名的列名，因为名称与行ID相同：如果ID为1234，则图像为images/img00001234.jpg。
否则你必须发出另一个查询：
UPDATE details SET filename='$newfile' WHERE id = $lastid;
在所有情况下，您都会收到有关要检索的行的一些信息;至少它的ID，或者你可以插入WHERE的某些条件。例如，如果您收到用户电子邮件（并且它是唯一键），则您将使用WHERE email='...'。
因此，您可以发出SELECT * FROM details WHERE...，在这些详细信息中，您会找到ID或filename字段。
在第一种情况下，您已经足够构建文件名，甚至不需要数据库查询，但请记住，任何知道该ID的人现在都可以访问该图像，这可能是无害的甚至是期望的（例如用户公共头像图像），但有时可能不是。
$lastid = (int)$_REQUEST['id'];
$newfile = sprintf("%s/img%08d.jpg", $folder, $lastid);
请注意，语法与上述相同; (int)演员要记住，这是用户提供的信息，可能包含各种恶意软件。
在第二种情况下，您将发出WHERE并从检索到的元组中获取ID或直接获取文件名字段。
拥有图像路径，您可以将其发送给用户...如果图像在那里。只是检查。
if (!is_readable($newfile))
{
Header('HTTP/1.0 404 Not Found')
readfile('/path/to/beautiful/error-page.html');
die();
}
// if you are really paranoid, or want to support different quality images,
// you can $gd = imageCreateFromJPEG($newfile); here, check it succeeded or
// send 404 / 500 error if it failed, manipulate $gd and send it along with
// ImageJPEG($gd, '', $quality); instead of the readfile() down there. With
// this approach, you'll better not send Content-Length, though. This makes
// image DOWNLOADS more awkward (you don't see "104K of 1.3M downloaded").
Header('Content-Type: image/jpeg');
Header('Content-Length: ' . filesize($newfile));
readfile($newfile);
die();
......就是这样。在调用上述内容的HTML源代码中，您可能有：
<img class="avatar" src="images.php?id=<?php echo $details['id']; ?>" />
（PHP生成HTML 需要来访问数据库并获取$details，当然）。
还有其他设置允许“调用”PHP以受保护的方式将数据库元组信息保存在_GET参数中，这样即使用户看到图像是使用
检索的image.php?id=1234
并且知道Bob有ID 7654，但仍然无法通过将1234更改为7654来检索图像，但我不知道这是否对某人感兴趣。
使用Web浏览器，设置内容就足够了。使用Internet Explorer，您可能需要以.jpg结束文件，而这可能需要使用URL重写方案。
答案 1 :(得分：0)
package com.example.test_image_save;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener {
protected static TextView textView;
protected static ImageView image1, image2;
protected Button get_image, save_image, read_image;
private String selectedImagePath;
private static final int SELECT_PICTURE = 1;
String DB_NAME = Environment.getExternalStorageDirectory() + "/test.db";
String TABLE_NAME = "mytable";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
image1 = (ImageView) findViewById(R.id.imageView1);
image2 = (ImageView) findViewById(R.id.imageView2);
textView = (TextView) findViewById(R.id.textView1);
get_image = (Button) findViewById(R.id.get_image);
get_image.setOnClickListener(this);
save_image = (Button) findViewById(R.id.save_image);
save_image.setOnClickListener(this);
read_image = (Button) findViewById(R.id.read_image);
read_image.setOnClickListener(this);
}
public void onClick(View v) {
int id = v.getId();
switch (id) {
case R.id.get_image:
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(
Intent.createChooser(intent, "Select Picture"),
SELECT_PICTURE);
break;
case R.id.save_image:
createTable();
saveInDB();
break;
case R.id.read_image:
readFromDB();
break;
default:
break;
}
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
if (requestCode == SELECT_PICTURE) {
Uri selectedImageUri = data.getData();
selectedImagePath = getPath(selectedImageUri);
System.out.println("Image Path : " + selectedImagePath);
image1.setVisibility(View.VISIBLE);
image1.setImageURI(selectedImageUri);
}
}
}
@SuppressWarnings("deprecation")
public String getPath(Uri uri) {
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(uri, projection, null, null, null);
int column_index = cursor
.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
void createTable() {
SQLiteDatabase myDb = openOrCreateDatabase(DB_NAME,
Context.MODE_PRIVATE, null);
String MySQL = "create table if not exists "
+ TABLE_NAME
+ " (_id INTEGER primary key autoincrement, name TEXT not null, image BLOB);";
myDb.execSQL(MySQL);
myDb.close();
}
void saveInDB() {
SQLiteDatabase myDb = openOrCreateDatabase(DB_NAME,
Context.MODE_PRIVATE, null);
byte[] byteImage1 = null;
String s = myDb.getPath();
myDb.execSQL("delete from " + TABLE_NAME); // clearing the table
ContentValues newValues = new ContentValues();
String name = "SachinImages";
newValues.put("name", name);
try {
FileInputStream instream = new FileInputStream(selectedImagePath);
BufferedInputStream bif = new BufferedInputStream(instream);
byteImage1 = new byte[bif.available()];
bif.read(byteImage1);
newValues.put("image", byteImage1);
long ret = myDb.insert(TABLE_NAME, null, newValues);
if (ret < 0)
textView.append("Error");
} catch (IOException e) {
textView.append("Error Exception : " + e.getMessage());
}
myDb.close();
textView.append("\n Saving Details \n Name : " + name);
textView.append("\n Image Size : " + byteImage1.length + " KB");
textView.append("\n Saved in DB : " + s + "\n");
Toast.makeText(this.getBaseContext(),
"Image Saved in DB successfully.", Toast.LENGTH_SHORT).show();
}
void readFromDB() {
byte[] byteImage2 = null;
SQLiteDatabase myDb;
myDb = openOrCreateDatabase(DB_NAME, Context.MODE_PRIVATE, null);
Cursor cur = myDb.query(TABLE_NAME, null, null, null, null, null, null);
cur.moveToFirst();
while (cur.isAfterLast() == false) {
textView.append("\n Reading Details \n Name : " + cur.getString(1));
cur.moveToNext();
}
// /////Read data from blob field////////////////////
cur.moveToFirst();
byteImage2 = cur.getBlob(cur.getColumnIndex("image"));
setImage(byteImage2);
cur.close();
myDb.close();
Toast.makeText(this.getBaseContext(),
"Image read from DB successfully.", Toast.LENGTH_SHORT).show();
Toast.makeText(this.getBaseContext(),
"If your image is big, please scrolldown to see the result.",
Toast.LENGTH_SHORT).show();
}
void setImage(byte[] byteImage2) {
image2.setImageBitmap(BitmapFactory.decodeByteArray(byteImage2, 0,
byteImage2.length));
textView.append("\n Image Size : " + byteImage2.length + " KB");
}
}