我想知道哪种是将图像上传到服务器而不会失去其质量的最佳方式。 我在谷歌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
我尝试过Base64编码，如果图像分辨率太高，它会导致OOM（内存不足）。 任何解决这个问题的教程都将受到赞赏。 提前致谢。
答案 0 :(得分：62)
Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, 1);
以上代码从画廊中选择图片
@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);
}
现在使用多页表单数据发布数据
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("LINK TO SERVER");
Multipart FORM DATA
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);
答案 1 :(得分：16)
采摘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();
}
}
}
php代码，用于处理上传图像，还可以从base64编码数据创建图像
<?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";
}
}
?>
答案 2 :(得分：6)
使用下面的代码可以帮助你......
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
答案 3 :(得分：3)
尝试使用此方法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());
}
}
使用课程上传
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"));
}
?>
答案 4 :(得分：0)
//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
}