Android 如何取消将文件从库上载到服务器
这是将图像从我的图库上载到服务器的代码。此代码正在运行 但在单击“后退”按钮时，它将被加载 现在我问的意思是，当我点击后退按钮时，它应该转到上一页，上传应该停止 我该怎么做 这是我的密码：Android 如何取消将文件从库上载到服务器,android,uploading,Android,Uploading,这是将图像从我的图库上载到服务器的代码。此代码正在运行 但在单击“后退”按钮时，它将被加载 现在我问的意思是，当我点击后退按钮时，它应该转到上一页，上传应该停止 我该怎么做 这是我的密码： package com.politicalmileage.chintamanvanga; import java.io.DataOutputStream; import java.io.File; import java.io.FileInputStream; import java.net.HttpURL
package com.politicalmileage.chintamanvanga;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Set;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
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 ContributeToTheSite extends Activity implements OnClickListener{
private TextView messageText;
private Button uploadButton, btnselectpic;
private ImageView imageview;
private int serverResponseCode = 0;
private ProgressDialog dialog = null;
private String upLoadServerUri = null;
private String imagepath=null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.contributetothesite);
uploadButton = (Button)findViewById(R.id.uploadButton);
messageText = (TextView)findViewById(R.id.messageText);
btnselectpic = (Button)findViewById(R.id.button_selectpic);
imageview = (ImageView)findViewById(R.id.imageView_pic);
btnselectpic.setOnClickListener(this);
uploadButton.setVisibility(View.INVISIBLE);
uploadButton.setOnClickListener(this);
upLoadServerUri = "http://url";
}
@Override
public void onClick(View arg0) {
if(arg0==btnselectpic)
{
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Complete action using"), 1);
}
else if (arg0==uploadButton) {
dialog = ProgressDialog.show(ContributeToTheSite.this, "", "Uploading file...", true);
messageText.setText("uploading started.....");
new Thread(new Runnable() {
public void run() {
uploadFile(imagepath);
}
}).start();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1 && resultCode == RESULT_OK) {
//Bitmap photo = (Bitmap) data.getData().getPath();
Uri selectedImageUri = data.getData();
imagepath = getPath(selectedImageUri);
Bitmap bitmap=BitmapFactory.decodeFile(imagepath);
imageview.setImageBitmap(bitmap);
messageText.setText("Uploading file path:" +imagepath);
uploadButton.setVisibility(View.VISIBLE);
}
}
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);
}
public int uploadFile(String sourceFileUri) {
String fileName = sourceFileUri;
HttpURLConnection conn = null;
DataOutputStream dos = null;
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1 * 1024 * 1024;
File sourceFile = new File(sourceFileUri);
if (!sourceFile.isFile()) {
dialog.dismiss();
Log.e("uploadFile", "Source File not exist :"+imagepath);
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("Source File not exist :"+ imagepath);
}
});
return 0;
}
else
{
try {
// open a URL connection to the Servlet
FileInputStream fileInputStream = new FileInputStream(sourceFile);
URL url = new URL(upLoadServerUri);
// Open a HTTP connection to the URL
conn = (HttpURLConnection) url.openConnection();
conn.setDoInput(true); // Allow Inputs
conn.setDoOutput(true); // Allow Outputs
conn.setUseCaches(false); // Don't use a Cached Copy
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("ENCTYPE", "multipart/form-data");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
conn.setRequestProperty("uploaded_file", fileName);
dos = new DataOutputStream(conn.getOutputStream());
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
+ fileName + "\"" + lineEnd);
dos.writeBytes(lineEnd);
// create a buffer of maximum size
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
// read file and write it into form...
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0) {
dos.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
// send multipart form data necesssary after file data...
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
// Responses from the server (code and message)
serverResponseCode = conn.getResponseCode();
String serverResponseMessage = conn.getResponseMessage();
Log.i("uploadFile", "HTTP Response is : "
+ serverResponseMessage + ": " + serverResponseCode);
if(serverResponseCode == 200){
runOnUiThread(new Runnable() {
public void run() {
String msg = "File Upload Completed.\n\n Thanks for Your Contribution to the Mobile App";
messageText.setText(msg);
Toast.makeText(ContributeToTheSite.this, "Thanks for Your Contribution to the Mobile App.", Toast.LENGTH_SHORT).show();
finish();
}
});
}
//close the streams //
fileInputStream.close();
dos.flush();
dos.close();
} catch (MalformedURLException ex) {
dialog.dismiss();
ex.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("MalformedURLException Exception : check script url.");
Toast.makeText(ContributeToTheSite.this, "MalformedURLException", Toast.LENGTH_SHORT).show();
}
});
Log.e("Upload file to server", "error: " + ex.getMessage(), ex);
} catch (Exception e) {
dialog.dismiss();
e.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("Got Exception : see logcat ");
Toast.makeText(ContributeToTheSite.this, "Got Exception : see logcat ", Toast.LENGTH_SHORT).show();
}
});
Log.e("Upload file to server Exception", "Exception : " + e.getMessage(), e);
}
dialog.dismiss();
return serverResponseCode;
} // End else block
}
}
当按下后退按钮时，您可以覆盖活动的onBackPressed方法以停止上载线程。您可以这样做。 首先，必须重写public void onBackPressed方法
else if (arg0==uploadButton) {
dialog = ProgressDialog.show(ContributeToTheSite.this, "", "Uploading file...", true);
messageText.setText("uploading started.....");
uploadThread = new Thread(new Runnable() {
public void run() {
uploadFile(imagepath);
}
}).start();
}
public void onBackPressed(){
uploadThread.stop();
super.onBackPressed();
}
public class ContributeToTheSite extends Activity implements OnClickListener{
private boolean sendingFile = false;
...
public void onClick(View arg0) {
if(arg0==btnselectpic)
{
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Complete action using"), 1);
}
else if (arg0==uploadButton) {
dialog = ProgressDialog.show(ContributeToTheSite.this, "", "Uploading file...", true);
messageText.setText("uploading started.....");
sendingFile = true;
new Thread(new Runnable() {
public void run() {
uploadFile(imagepath);
}
}).start();
}
}
public void onBackPressed(){
sendingFile = false;
super.onBackPressed();
}
public int uploadFile(String sourceFileUri) {
...
while (bytesRead > 0 && sendingFile ) {
dos.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
if( !sendingFile ){
//to do send message server sending file is canceled.
return -1;
}
sendingFile = false;
...
...
实际上，您可以从下面的问题中定义的以下方法中断当前线程。 我认为不必创建线程，您必须使用asynctask并取消当前的asynctask，这非常容易处理 试试这个
public void onBackPressed() {
// Do Here what ever you want do on back press;
if (conn != null)
{
conn.disconnect();
}
finish();
}
使用一个处理程序，然后你可以随时停止处理程序，但要知道这并不保证它不会被上传。你可以给我举个小例子吗？它不起作用。你能告诉我如何使用这个吗？我是新来的android@user3374790显示我编辑的答案。这种方式是取消发送文件，但您可以在服务器中控制这种情况。