我想知道在不失去图像质量的情况下将图像上传到服务器的最佳方法。
我在谷歌上搜索了许多发布数据的方法，但我不确定哪种方法最适合上传。
我找到了以下几种方式：
- 多部分图像上传。
- 使用字节数组上传图像
- 使用Base64编码的字符串上传图像。
我尝试过 Base64 编码，但如果图像分辨率太高，会导致内存溢出（OOM）。
上传图片至服务器 Android
101
- Manoj
1
8多部分图像加载很好用，如果需要的话可以尝试一下，我会提供代码。 - Nitin Misra
5个回答
93
Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, 1);
以上代码用于从图库中选择图片
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 1)
if (resultCode == Activity.RESULT_OK) {
Uri selectedImage = data.getData();
String filePath = getPath(selectedImage);
String file_extn = filePath.substring(filePath.lastIndexOf(".") + 1);
image_name_tv.setText(filePath);
try {
if (file_extn.equals("img") || file_extn.equals("jpg") || file_extn.equals("jpeg") || file_extn.equals("gif") || file_extn.equals("png")) {
//FINE
} else {
//NOT IN REQUIRED FORMAT
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public String getPath(Uri uri) {
String[] projection = {MediaColumns.DATA};
Cursor cursor = managedQuery(uri, projection, null, null, null);
column_index = cursor
.getColumnIndexOrThrow(MediaColumns.DATA);
cursor.moveToFirst();
imagePath = cursor.getString(column_index);
return cursor.getString(column_index);
}
现在使用多部分表单数据发布数据
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("LINK TO SERVER");
多部分表单数据
MultipartEntity mpEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);
if (filePath != null) {
File file = new File(filePath);
Log.d("EDIT USER PROFILE", "UPLOAD: file length = " + file.length());
Log.d("EDIT USER PROFILE", "UPLOAD: file exist = " + file.exists());
mpEntity.addPart("avatar", new FileBody(file, "application/octet"));
}
最终将数据发送到服务器
httppost.setEntity(mpEntity);
HttpResponse response = httpclient.execute(httppost);
- Nitin Misra
5
3如果Nitin的解决方案对你有帮助，请@Manoj将该答案标记为正确。 - Sanand Sule
12@DwivediJi，您也可以发布您的答案，这样人们就可以从中受益，没有冒犯之意。 - Nitin Misra
3根据我的理解，您正在运行安卓6.0或更高版本，因此需要遵守新的安卓权限模型并请求用户允许访问读写外部存储。请参考以下链接了解更多信息：http://developer.android.com/training/permissions/index.html - Nitin Misra
3HTTPPOST 的 gradle 是什么？ - Mikheil Zhghenti
1这需要更多的背景信息。例如，Gradle命令是什么，为了使其编译，需要哪些导入？ - SMBiggs
19
主活动类以拍照并上传文件
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.MediaStore;
//import android.util.Base64;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
public class MainActivity extends Activity {
Button btpic, btnup;
private Uri fileUri;
String picturePath;
Uri selectedImage;
Bitmap photo;
String ba1;
public static String URL = "Paste your URL here";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btpic = (Button) findViewById(R.id.cpic);
btpic.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
clickpic();
}
});
btnup = (Button) findViewById(R.id.up);
btnup.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
upload();
}
});
}
private void upload() {
// Image location URL
Log.e("path", "----------------" + picturePath);
// Image
Bitmap bm = BitmapFactory.decodeFile(picturePath);
ByteArrayOutputStream bao = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG, 90, bao);
byte[] ba = bao.toByteArray();
//ba1 = Base64.encodeBytes(ba);
Log.e("base64", "-----" + ba1);
// Upload image to server
new uploadToServer().execute();
}
private void clickpic() {
// Check Camera
if (getApplicationContext().getPackageManager().hasSystemFeature(
PackageManager.FEATURE_CAMERA)) {
// Open default camera
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
// start the image capture Intent
startActivityForResult(intent, 100);
} else {
Toast.makeText(getApplication(), "Camera not supported", Toast.LENGTH_LONG).show();
}
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 100 && resultCode == RESULT_OK) {
selectedImage = data.getData();
photo = (Bitmap) data.getExtras().get("data");
// Cursor to get image uri to display
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
picturePath = cursor.getString(columnIndex);
cursor.close();
Bitmap photo = (Bitmap) data.getExtras().get("data");
ImageView imageView = (ImageView) findViewById(R.id.Imageprev);
imageView.setImageBitmap(photo);
}
}
public class uploadToServer extends AsyncTask<Void, Void, String> {
private ProgressDialog pd = new ProgressDialog(MainActivity.this);
protected void onPreExecute() {
super.onPreExecute();
pd.setMessage("Wait image uploading!");
pd.show();
}
@Override
protected String doInBackground(Void... params) {
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("base64", ba1));
nameValuePairs.add(new BasicNameValuePair("ImageName", System.currentTimeMillis() + ".jpg"));
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(URL);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
String st = EntityUtils.toString(response.getEntity());
Log.v("log_tag", "In the try Loop" + st);
} catch (Exception e) {
Log.v("log_tag", "Error in http connection " + e.toString());
}
return "Success";
}
protected void onPostExecute(String result) {
super.onPostExecute(result);
pd.hide();
pd.dismiss();
}
}
}
处理上传图像并从base64编码数据创建图像的PHP代码
<?php
error_reporting(E_ALL);
if(isset($_POST['ImageName'])){
$imgname = $_POST['ImageName'];
$imsrc = base64_decode($_POST['base64']);
$fp = fopen($imgname, 'w');
fwrite($fp, $imsrc);
if(fclose($fp)){
echo "Image uploaded";
}else{
echo "Error uploading image";
}
}
?>
- Manoj DB
1
2由于大部分代码已经过时，我一直在尝试更新代码...这非常令人沮丧。 :) 我已经成功将“NameValuePair”替换为“Pair”，并且正在使用HttpUrlConnection而不是apache的东西。但是我在“post”部分迷失了方向。 - mystic cola
9
使用以下代码可以帮助你......
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 4;
options.inPurgeable = true;
Bitmap bm = BitmapFactory.decodeFile("your path of image",options);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG,40,baos);
// bitmap object
byteImage_photo = baos.toByteArray();
//generate base64 string of image
String encodedImage =Base64.encodeToString(byteImage_photo,Base64.DEFAULT);
//send this encoded string to server
- kaveri Patel
6
尝试使用这种方法来从相机上传图像文件。
package com.example.imageupload;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.message.BasicHeader;
public class MultipartEntity implements HttpEntity {
private String boundary = null;
ByteArrayOutputStream out = new ByteArrayOutputStream();
boolean isSetLast = false;
boolean isSetFirst = false;
public MultipartEntity() {
this.boundary = System.currentTimeMillis() + "";
}
public void writeFirstBoundaryIfNeeds() {
if (!isSetFirst) {
try {
out.write(("--" + boundary + "\r\n").getBytes());
} catch (final IOException e) {
}
}
isSetFirst = true;
}
public void writeLastBoundaryIfNeeds() {
if (isSetLast) {
return;
}
try {
out.write(("\r\n--" + boundary + "--\r\n").getBytes());
} catch (final IOException e) {
}
isSetLast = true;
}
public void addPart(final String key, final String value) {
writeFirstBoundaryIfNeeds();
try {
out.write(("Content-Disposition: form-data; name=\"" + key + "\"\r\n")
.getBytes());
out.write("Content-Type: text/plain; charset=UTF-8\r\n".getBytes());
out.write("Content-Transfer-Encoding: 8bit\r\n\r\n".getBytes());
out.write(value.getBytes());
out.write(("\r\n--" + boundary + "\r\n").getBytes());
} catch (final IOException e) {
}
}
public void addPart(final String key, final String fileName,
final InputStream fin) {
addPart(key, fileName, fin, "application/octet-stream");
}
public void addPart(final String key, final String fileName,
final InputStream fin, String type) {
writeFirstBoundaryIfNeeds();
try {
type = "Content-Type: " + type + "\r\n";
out.write(("Content-Disposition: form-data; name=\"" + key
+ "\"; filename=\"" + fileName + "\"\r\n").getBytes());
out.write(type.getBytes());
out.write("Content-Transfer-Encoding: binary\r\n\r\n".getBytes());
final byte[] tmp = new byte[4096];
int l = 0;
while ((l = fin.read(tmp)) != -1) {
out.write(tmp, 0, l);
}
out.flush();
} catch (final IOException e) {
} finally {
try {
fin.close();
} catch (final IOException e) {
}
}
}
public void addPart(final String key, final File value) {
try {
addPart(key, value.getName(), new FileInputStream(value));
} catch (final FileNotFoundException e) {
}
}
public long getContentLength() {
writeLastBoundaryIfNeeds();
return out.toByteArray().length;
}
public Header getContentType() {
return new BasicHeader("Content-Type", "multipart/form-data; boundary="
+ boundary);
}
public boolean isChunked() {
return false;
}
public boolean isRepeatable() {
return false;
}
public boolean isStreaming() {
return false;
}
public void writeTo(final OutputStream outstream) throws IOException {
outstream.write(out.toByteArray());
}
public Header getContentEncoding() {
return null;
}
public void consumeContent() throws IOException,
UnsupportedOperationException {
if (isStreaming()) {
throw new UnsupportedOperationException(
"Streaming entity does not implement #consumeContent()");
}
}
public InputStream getContent() throws IOException,
UnsupportedOperationException {
return new ByteArrayInputStream(out.toByteArray());
}
}
使用类上传文件
private void doFileUpload(File file_path) {
Log.d("Uri", "Do file path" + file_path);
try {
HttpClient client = new DefaultHttpClient();
//use your server path of php file
HttpPost post = new HttpPost(ServerUploadPath);
Log.d("ServerPath", "Path" + ServerUploadPath);
FileBody bin1 = new FileBody(file_path);
Log.d("Enter", "Filebody complete " + bin1);
MultipartEntity reqEntity = new MultipartEntity();
reqEntity.addPart("uploaded_file", bin1);
reqEntity.addPart("email", new StringBody(useremail));
post.setEntity(reqEntity);
Log.d("Enter", "Image send complete");
HttpResponse response = client.execute(post);
resEntity = response.getEntity();
Log.d("Enter", "Get Response");
try {
final String response_str = EntityUtils.toString(resEntity);
if (resEntity != null) {
Log.i("RESPONSE", response_str);
JSONObject jobj = new JSONObject(response_str);
result = jobj.getString("ResponseCode");
Log.e("Result", "...." + result);
}
} catch (Exception ex) {
Log.e("Debug", "error: " + ex.getMessage(), ex);
}
} catch (Exception e) {
Log.e("Upload Exception", "");
e.printStackTrace();
}
}
上传服务
<?php
$image_name = $_FILES["uploaded_file"]["name"];
$tmp_arr = explode(".",$image_name);
$img_extn = end($tmp_arr);
$new_image_name = 'image_'. uniqid() .'.'.$img_extn;
$flag=0;
if (file_exists("Images/".$new_image_name))
{
$msg=$new_image_name . " already exists."
header('Content-type: application/json');
echo json_encode(array("ResponseCode"=>"2","ResponseMsg"=>$msg));
}else{
move_uploaded_file($_FILES["uploaded_file"]["tmp_name"],"Images/". $new_image_name);
$flag = 1;
}
if($flag == 1){
require 'db.php';
$static_url =$new_image_name;
$conn=mysql_connect($db_host,$db_username,$db_password) or die("unable to connect localhost".mysql_error());
$db=mysql_select_db($db_database,$conn) or die("unable to select message_app");
$email = "";
if((isset($_REQUEST['email'])))
{
$email = $_REQUEST['email'];
}
$sql ="insert into alert(images) values('$static_url')";
$result=mysql_query($sql);
if($result){
echo json_encode(array("ResponseCode"=>"1","ResponseMsg"=> "Insert data successfully.","Result"=>"True","ImageName"=>$static_url,"email"=>$email));
} else
{
echo json_encode(array("ResponseCode"=>"2","ResponseMsg"=> "Could not insert data.","Result"=>"False","email"=>$email));
}
}
else{
echo json_encode(array("ResponseCode"=>"2","ResponseMsg"=> "Erroe While Inserting Image.","Result"=>"False"));
}
?>
- Kaushik Kyada
5
3org.apache.http在API 23中已被弃用。请将这个示例更新为使用HttpURLConnection。 - MustModify
@MustModify 谷歌使用库 'org.apache.http.legacy' - Lakshmi Narayanan
4为什么要使用标记为“legacy”的库？难道没有替代品吗？ - MustModify
何时使用遗留版本？当您在旧的Celeron上安装了32位Ubuntu的Gradle，并且只能使用旧版本的构建工具时。并且它可以100％正常工作。那就是何时 :) - Gavin Simpson
代码的剩余部分在哪里？这里引用了各种没有定义的变量。它们是用来做什么的？我可以弄清一些，但是我不够理解这个程序，无法确定哪些是必要的哪些是多余的（如果我能，就不会在这里了！）。 - SMBiggs
1
//Kotlin Version
private fun setImageForUploading (imagePath:String):String{
val options = BitmapFactory.Options();
options.inSampleSize = 2
//options.inPurgeable = true //deprecated
val bitmap = BitmapFactory.decodeFile(imagePath,options)
val byteArrayOutPutStream = ByteArrayOutputStream()
bitmap.compress(Bitmap.CompressFormat.PNG,90,byteArrayOutPutStream)
// bitmap object
val byteImagePhoto = byteArrayOutPutStream.toByteArray()
//generate base64 string of image
val encodedImage = Base64.encodeToString(byteImagePhoto,Base64.DEFAULT)
return encodedImage
}
- Mohamed Dahab
1
这是……我们该怎么说呢……不完整的？是的，非常不完整。代码的剩余部分在哪里？ - SMBiggs
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