我想知道在不降低质量的情况下将图像上传到服务器的最佳方式是什么。 我在谷歌上搜索发现了各种发布数据的方法。但我不确定哪一个最好上传。 我遇到了
我已经尝试过 Base64 编码，如果图像分辨率太高，它会导致我出现 OOM（内存不足）。 任何解决此问题的教程将不胜感激。 提前致谢。
【问题讨论】：
标签： android http-post image-uploading
Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, 1);
从图库中选择图像的代码
@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"));
}
最终将数据发布到服务器
httppost.setEntity(mpEntity);
HttpResponse response = httpclient.execute(httppost);
【讨论】：
要挑选和上传的主要活动类
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();
}
}
}
用于处理上传图片并从 base64 编码数据创建图片的 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";
}
}
?>
【讨论】：
使用下面的代码对你有帮助....
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
【讨论】：
试试这个方法从相机上传图片文件
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());
}
}
使用类进行上传
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"));
}
?>
【讨论】：
//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
}
【讨论】：