我试图将图像上传到服务器，但不知何故，代码停在FileInputStream行。不知道为什么，我不知道如何调试或检查它。这里是我的源代码：
public class CreateSetcardStep1Activity extends AppCompatActivity {
@Override
protected void onCreate(final Bundle savedInstanceState) {
String filename = appHelper.dateToString(new Date(), "yyyyMMdd-hhmmss");
destination = new File(Environment.getExternalStorageDirectory(), filename + ".jpg");
buttonTakePhoto.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(destination));
startActivityForResult(intent, REQUEST_IMAGE);
}
});
buttonSubmitPhoto.setVisibility(View.GONE);
buttonSubmitPhoto.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
dialog = ProgressDialog.show(CreateSetcardStep1Activity.this, "", "Uploading file...", true);
new Thread(new Runnable() {
public void run() {
uploadFile(imagePath);
}
}).start();
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_IMAGE && resultCode == Activity.RESULT_OK) {
try {
buttonSubmitPhoto.setVisibility(View.VISIBLE);
Log.e(LOG, "breakpoint 1");
setcardPic.setVisibility(View.VISIBLE); Log.e(LOG, "breakpoint 2 destination: "+destination);
FileInputStream in = new FileInputStream(destination); Log.e(LOG, "breakpoint 3");
BitmapFactory.Options options = new BitmapFactory.Options(); Log.e(LOG, "breakpoint 4");
options.inSampleSize = 10; Log.e(LOG, "breakpoint 5");
imagePath = destination.getAbsolutePath(); Log.e(LOG, "breakpoint 6 imagePath: "+imagePath);
Log.e(LOG, "PATH === " + imagePath);
//tvPath.setText(imagePath);
Bitmap bmp = BitmapFactory.decodeStream(in, null, options);
setcardPic.setImageBitmap(bmp);
showUploadButton = true;
} catch (FileNotFoundException e) {
e.printStackTrace();
}
} else {
showUploadButton = false;
Toast.makeText(getApplicationContext(),
R.string.request_cancelled,
Toast.LENGTH_LONG).show();
}
}
public int uploadFile(String sourceFileUri) {
String fileName = sourceFileUri;
showUploadButton = false; //revert upload button to hidden
HttpURLConnection conn = null;
DataOutputStream dos = null;
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1024 * 1024;
File sourceFile = new File(sourceFileUri);
if (!sourceFile.isFile()) {
dialog.dismiss();
Log.e(LOG, "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("Filedata", 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(LOG, "HTTP Response is : "+ serverResponseMessage + ": " + serverResponseCode);
if(serverResponseCode == 200){
runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(CreateSetcardStep1Activity.this, "File Upload Complete.",
Toast.LENGTH_SHORT).show();
}
});
}
//close the streams //
fileInputStream.close();
dos.flush();
dos.close();
} catch (MalformedURLException ex) {
dialog.dismiss();
ex.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(CreateSetcardStep1Activity.this, "MalformedURLException",
Toast.LENGTH_SHORT).show();
}
});
Log.e(LOG, "error: " + ex.getMessage(), ex);
} catch (Exception e) {
dialog.dismiss();
e.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(CreateSetcardStep1Activity.this, "Got Exception : see logcat ",
Toast.LENGTH_SHORT).show();
}
});
Log.e(LOG, "Exception : "
+ e.getMessage(), e);
}
dialog.dismiss();
return serverResponseCode;
}
}
}
有没有办法检查问题所在？ logcat在断点2停止：断点2目的地：/storage/emulated/0/20171215-051851.jpg 如果我检查资源管理器
，那么文件就在那里答案 0 :(得分：1)
这是因为您没有请求EXTERNAL_STORAGE权限。
从android API级别23（marshmallow）开始，android权限框架（我不知道这是否是正确的术语），已经改变。
在marshmallow之前，您只需要在清单文件中声明权限。但是在棉花糖之上，Android权限已被分类为Normal permissions和Dangerous permissions。如果您使用的是普通权限，则所有Android版本的内容都是相同的。但如果您使用危险权限，则必须请求用户在运行时授予该权限。
在您的情况下，您正在上传图像，该图像需要READ_EXTERNAL_STORAGE和WRITE_EXTERNAL_STORAGE权限。这些被归类为危险权限。因此，在执行任何需要这些权限的操作之前，您必须先请求这些权限。
但您不必单独请求这两个权限，因为这些权限属于permission group之一。
来自官方文档，
如果某个应用请求其清单中列出的危险权限，并且该应用已在同一权限组中拥有其他危险权限，则系统会立即授予该权限，而不会与该用户进行任何互动..
即，如果您声明了一个权限组上的一些权限，则必须仅请求其中一个权限。如果用户授予该权限组的权限，则系统将授予您声明的所有权限，这些权限位于同一权限组中。
以下是请求存储权限的代码
private static final int STORAGE_REQ_ID=3465;
if (ContextCompat.checkSelfPermission(CreateSetcardStep1Activity.this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)
{
if (ActivityCompat.shouldShowRequestPermissionRationale(CreateSetcardStep1Activity.this,
Manifest.permission.READ_EXTERNAL_STORAGE)) {
//THIS CONDITION WORKS WHEN WE ARE REQUSETING PERMISSION AGAIN SINCE USER DENIED PERMISSION ON PREVIOUS REQUEST(S)
ActivityCompat.requestPermissions(CreateSetcardStep1Activity.this,
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
STORAGE_REQ_ID);
} else {
//REQUESTING PERMISSION FOR FIRST TIME, EXPLAIN WHY THE APPLICATION NEED PERMISSION
AlertDialog.Builder builder = new AlertDialog.Builder(CreateSetcardStep1Activity.this);
builder.setTitle("Permission Request");
builder.setMessage("To upload image, Application need External storage permission");
builder.setPositiveButton("Grant", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
ActivityCompat.requestPermissions(CreateSetcardStep1Activity.this,
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
STORAGE_REQ_ID);
}
});
builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
}
});
AlertDialog dialog = builder.create();
dialog.show();
ActivityCompat.requestPermissions(CreateSetcardStep1Activity.this,
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
STORAGE_REQ_ID);
}
}
else startImageCapture();
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
//HERE YOU HANDLE PERMISSION REQUEST RESULTS
switch (requestCode) {
case STORAGE_REQ_ID: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//PERMISSION GRANTED!!
startImageCapture();
} else {
//USER DENIED PERMISSION, NOTIFY THE USER THAT PERMISSION IS DENIED, MAY BE A TOAST?
}
return;
}
}
}
private void startImageCapture(){
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(destination));
startActivityForResult(intent, REQUEST_IMAGE);
}
其他一切都差不多。 （抱歉我的英语不好）
有关权限请求的更多信息here
答案 1 :(得分：0)
嗨，首先请检查（如果使用外部，写入外部和相机，如果使用的话）权限到Manifest文件中，然后为大型Marshmallow设备添加运行时权限代码。并使用文件提供程序从SD卡获取Image Uri。
将下面的代码放入onActivityResult（）。
if (mPhotouri != null) {
try {
mBitmap = MediaStore.Images.Media.getBitmap(
getContentResolver(), mPhotouri);
Uri tempUri = getImageUri(this, mBitmap);
finalFile = new File(getRealPathFromURI(tempUri, this));
mSelectedImagePath = finalFile.getAbsolutePath();
if (mSelectedImagePath != null)
mFileSelectedImage = new File(mSelectedImagePath);
} catch (Exception e) {
e.printStackTrace();
}
}
public static Uri getImageUri(Activity inContext, Bitmap inImage) {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
inImage.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
String path = MediaStore.Images.Media.insertImage(inContext.getContentResolver(), inImage, "Title", null);
return Uri.parse(path);
}
public static String getRealPathFromURI(Uri uri, Activity signupActivity) {
Cursor cursor = signupActivity.getContentResolver().query(uri, null, null, null, null);
cursor.moveToFirst();
int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
return cursor.getString(idx);
}
答案 2 :(得分：0)
将此添加到AndroidManifest.xml：
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
对于api 23+，请阅读本教程：