我在尝试将摄像头拍摄的图像保存到手机的存储空间时遇到问题，但是我一直收到一个错误，我之前没有看到过会说File.createNewFile（）会被忽略。有人如何纠正这一点，以便保存照片？或者是否有另一种可能更好的方法，我可以保存相机捕获的图像并将其显示在ImageView中？问题区域可以在PICK_IMAGE_CAMERA else if else下的onActivityResult（）中找到。
主要活动
package com.example.stins.orbotcamera;
import android.Manifest;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Environment;
import android.provider.MediaStore;
import android.provider.Settings;
import android.provider.SyncStateContract;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.content.FileProvider;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.util.Base64;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import net.gotev.uploadservice.MultipartUploadRequest;
import net.gotev.uploadservice.UploadNotificationConfig;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
import java.util.UUID;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private FloatingActionButton fab;
private ImageView imageView;
private Uri file;
private GPSTracker gps;
private EditText imageComment;
private CoordinatorLayout coordinatorLayout;
private TextView imageLat, imageLong;
private String mLat, mLong;
private File destination = null;
private String imgPath = null;
String mCurrentPhotoPath;
public static final String UPLOAD_URL = "http://192.168.1.77/UploadExamples/upload.php";
private Bitmap bitmap;
private final int PICK_IMAGE_CAMERA = 1, PICK_IMAGE_GALLERY = 2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fab = (FloatingActionButton) findViewById(R.id.fab);
imageView = (ImageView) findViewById(R.id.imageView);
imageComment = (EditText) findViewById(R.id.imageComment);
imageLat = (TextView) findViewById(R.id.imageLat);
imageLong = (TextView) findViewById(R.id.imageLong);
//fab.setOnClickListener(this);
if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
fab.setEnabled(false);
imageComment.setEnabled(false);
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, 0);
}
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
selectImage();
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (requestCode == 0) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED
&& grantResults[1] == PackageManager.PERMISSION_GRANTED) {
fab.setEnabled(true);
imageComment.setEnabled(true);
}
else{
coordinatorLayout = (CoordinatorLayout) findViewById(R.id.coordinatorLayout);
final Snackbar snackbar = Snackbar
.make(coordinatorLayout, "Accept all permissions to use app", Snackbar.LENGTH_INDEFINITE);
snackbar.setAction("OK", new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent i = getBaseContext().getPackageManager()
.getLaunchIntentForPackage( getBaseContext().getPackageName() );
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
});
snackbar.setActionTextColor(Color.WHITE);
View sbView = snackbar.getView();
TextView textView = (TextView) sbView.findViewById(android.support.design.R.id.snackbar_text);
textView.setTextColor(Color.GRAY);
snackbar.show();
}
}
}
public void selectImage(){
try {
PackageManager pm = getPackageManager();
int hasPerm = pm.checkPermission(Manifest.permission.CAMERA, getPackageName());
if (hasPerm == PackageManager.PERMISSION_GRANTED) {
final CharSequence[] options = {"Take Photo", "Choose From Gallery","Cancel"};
android.support.v7.app.AlertDialog.Builder builder = new android.support.v7.app.AlertDialog.Builder(MainActivity.this);
builder.setTitle("Select Option");
builder.setItems(options, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int item) {
if (options[item].equals("Take Photo")) {
dialog.dismiss();
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, PICK_IMAGE_CAMERA);
} else if (options[item].equals("Choose From Gallery")) {
dialog.dismiss();
Intent pickPhoto = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(pickPhoto, PICK_IMAGE_GALLERY);
} else if (options[item].equals("Cancel")) {
dialog.dismiss();
}
}
});
builder.show();
} else
Toast.makeText(this, "Camera Permission error", Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(this, "Camera Permission error", Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
public void uploadImage() {
//getting name for the image
String name = imageComment.getText().toString().trim();
//getting the actual path of the image
String path = getPath(file);
//Uploading code
try {
String uploadId = UUID.randomUUID().toString();
//Creating a multi part request
new MultipartUploadRequest(this, uploadId, UPLOAD_URL)
.addFileToUpload(path, "image") //Adding file
.addParameter("name", name) //Adding text parameter to the request
.addParameter("latitude", mLat)
.addParameter("longitude", mLong)
.setNotificationConfig(new UploadNotificationConfig())
.setMaxRetries(2)
.startUpload(); //Starting the upload
Log.d("Upload", "uploadImage: " + path);
} catch (Exception exc) {
Toast.makeText(this, exc.getMessage(), Toast.LENGTH_SHORT).show();
}
}
public String getPath(Uri uri) {
Cursor cursor = getContentResolver().query(uri, null, null, null, null);
if (cursor != null) {
cursor.moveToFirst();
}
String document_id = null;
if (cursor != null) {
document_id = cursor.getString(0);
}
if (document_id != null) {
document_id = document_id.substring(document_id.lastIndexOf(":") + 1);
}
if (cursor != null) {
cursor.close();
}
cursor = getContentResolver().query(
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
null, MediaStore.Images.Media._ID + " = ? ", new String[]{document_id}, null);
if (cursor != null) {
cursor.moveToFirst();
}
String path = null;
if (cursor != null) {
path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
}
if (cursor != null) {
cursor.close();
}
return path;
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 0 && resultCode == RESULT_OK && data != null && data.getData() != null) {
file = data.getData();
try {
bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), file);
imageView.setImageBitmap(bitmap);
imageComment.setVisibility(View.VISIBLE);
} catch (IOException e) {
e.printStackTrace();
}
}
if (requestCode == 0) {
gps = new GPSTracker(MainActivity.this);
if (resultCode == RESULT_OK) {
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
mLat = Double.toString(latitude);
mLong = Double.toString(longitude);
imageLat.setText(mLat);
imageLong.setText(mLong);
// \n is for new line
//Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
coordinatorLayout = (CoordinatorLayout) findViewById(R.id.coordinatorLayout);
final Snackbar snackbar = Snackbar
.make(coordinatorLayout, "Current location recorded", Snackbar.LENGTH_LONG);
snackbar.setActionTextColor(Color.WHITE);
View sbView = snackbar.getView();
TextView textView = (TextView) sbView.findViewById(android.support.design.R.id.snackbar_text);
textView.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_location_on_white_24dp,0,0,0);
textView.setTextColor(Color.WHITE);
snackbar.show();
} else {
// Can't get location.
// GPS or network is not enabled.
// Ask user to enable GPS/network in settings.
}
} else if (resultCode == RESULT_CANCELED) {
// user cancelled Image capture
coordinatorLayout = (CoordinatorLayout) findViewById(R.id.coordinatorLayout);
final Snackbar snackbar = Snackbar
.make(coordinatorLayout,"Picture Cancelled", Snackbar.LENGTH_SHORT);
View sbView = snackbar.getView();
TextView textView = (TextView) sbView.findViewById(android.support.design.R.id.snackbar_text);
textView.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_cancel_white_24dp,0,0,0);
textView.setTextColor(Color.WHITE);
snackbar.show();
} else {
// failed to capture image
coordinatorLayout = (CoordinatorLayout) findViewById(R.id.coordinatorLayout);
final Snackbar snackbar = Snackbar
.make(coordinatorLayout,"Error Taking Picture", Snackbar.LENGTH_SHORT);
View sbView = snackbar.getView();
TextView textView = (TextView) sbView.findViewById(android.support.design.R.id.snackbar_text);
textView.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_error_outline_white_24dp,0,0,0);
textView.setTextColor(Color.WHITE);
snackbar.show();
}
}
if (requestCode == PICK_IMAGE_CAMERA && (data!=null)) {
try {
file = data.getData();
bitmap = (Bitmap) data.getExtras().get("data");
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
//bitmap.compress(Bitmap.CompressFormat.JPEG, 50, bytes);
Log.e("Activity", "Pick from Camera::>>> ");
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(new Date());
destination = new File(Environment.getExternalStorageDirectory() + "/" +
getString(R.string.app_name), "IMG_" + timeStamp + ".jpg");
FileOutputStream fo;
try {
destination.createNewFile();
fo = new FileOutputStream(destination);
fo.write(bytes.toByteArray());
fo.close();
} catch (IOException e) {
e.printStackTrace();
}
imgPath = destination.getAbsolutePath();
imageView.setImageBitmap(bitmap);
imageComment.setVisibility(View.VISIBLE);
} catch (Exception e) {
e.printStackTrace();
}
} else if (requestCode == PICK_IMAGE_GALLERY && (data!=null)) {
file = data.getData();
try {
bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), file);
Log.e("Activity", "Pick from Gallery::>>> ");
imgPath = getPath(file);
destination = new File(imgPath);
imageView.setImageBitmap(bitmap);
imageComment.setVisibility(View.VISIBLE);
} catch (Exception e) {
e.printStackTrace();
}
}
}
private static File getOutputMediaFile() {
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "OrbotCamera");
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("OrbotCamera", "failed to create directory");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
return new File(mediaStorageDir.getPath() + File.separator +
"IMG_" + timeStamp + ".jpg");
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
switch (item.getItemId()) {
case R.id.action_send:
if(imageView.getDrawable()==null){
coordinatorLayout = (CoordinatorLayout) findViewById(R.id.coordinatorLayout);
final Snackbar snackbar = Snackbar
.make(coordinatorLayout,"Sorry, you'll need an image for that!", Snackbar.LENGTH_SHORT);
View sbView = snackbar.getView();
TextView textView = (TextView) sbView.findViewById(android.support.design.R.id.snackbar_text);
textView.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_error_outline_white_24dp,0,0,0);
textView.setTextColor(Color.WHITE);
snackbar.show();
}
else {
uploadImage();
}
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onBackPressed() {
new AlertDialog.Builder(this, R.style.Theme_AppCompat_Dialog_Alert)
.setTitle("Exit")
.setMessage("Are you sure you want to close Orbot Camera?")
.setPositiveButton("Yes", new DialogInterface.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int which) {
finish();
}
})
.setNegativeButton("No", null)
.show();
}
@Override
public void onClick(View v) {
Intent i;
if(v.getId()==R.id.fab)
{
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), 0);
}
}
}
logcat的
07-26 10:56:30.757 23865-23865/com.example.stins.orbotcamera E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.stins.orbotcamera, PID: 23865
java.lang.NullPointerException: uri
at com.android.internal.util.Preconditions.checkNotNull(Preconditions.java:111)
at android.content.ContentResolver.query(ContentResolver.java:519)
at android.content.ContentResolver.query(ContentResolver.java:478)
at com.example.stins.orbotcamera.MainActivity.getPath(MainActivity.java:215)
at com.example.stins.orbotcamera.MainActivity.uploadImage(MainActivity.java:188)
at com.example.stins.orbotcamera.MainActivity.onOptionsItemSelected(MainActivity.java:427)
at android.app.Activity.onMenuItemSelected(Activity.java:3383)
at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:408)
at android.support.v7.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:195)
at android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:113)
at android.support.v7.app.AppCompatDelegateImplV9.onMenuItemSelected(AppCompatDelegateImplV9.java:679)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:959)
at android.support.v7.widget.ActionMenuView.invokeItem(ActionMenuView.java:623)
at android.support.v7.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:154)
at android.view.View.performClick(View.java:6261)
at android.widget.TextView.performClick(TextView.java:11157)
at android.view.View$PerformClick.run(View.java:23748)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
答案 0 :(得分：0)
尝试使用此方法
String file_path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)+"";
File dir = new File(file_path);
if(!dir.exists()){
dir.mkdirs();
}
File cacheDir = getCacheDir();
File file1 = new File(cacheDir, dir.toString());
file1.delete();
file = new File(dir, "temp.jpeg");
FileOutputStream fo;
try
{
fo = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fo);
fo.flush();
fo.close();
}
catch (IOException e)
{
e.printStackTrace();
}