Develop Reference

Phone not making calls with Intent Android_Call

I'm having some trouble with Intent Action_Call. I put the permission in Manifest, but it doesn't work. I press the button to Call and nothing happens. The app that I'm making is an app that does multiple Intents so the code isn't in MainActivity. I don't know if it helps, but I'm using API 28.
Thanks for reading.
MANIFEST:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.intentsimplicitas">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.CALL_PHONE"/>
<uses-permission android:name="android.permission.READ_SMS" />
<uses-permission android:name="android.permission.WRITE_SMS" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".SmsActivity"></activity>
<activity android:name=".DialActivity" />
<activity android:name=".WaysActivity" />
<activity android:name=".MapActivity" />
<activity android:name=".PageActivity" />
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
JAVA (DialActivity.java)
public class DialActivity extends Activity {
Button btnDial;
EditText edtPhone;
String phone;
Intent it;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dial);
btnDial = (Button)findViewById(R.id.btnDial);
edtPhone = (EditText)findViewById(R.id.edtPhone);
}
public void dialClick (View v) {
phone = edtPhone.getText().toString();
Uri uri = Uri.parse("tel: " + phone);
it = new Intent(Intent.ACTION_CALL);
it.setData(uri);
startActivity(it);
}
}

From https://developer.android.com/training/permissions/requesting:
Requesting permission:
// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(thisActivity,
Manifest.permission.CALL_PHONE)
!= PackageManager.PERMISSION_GRANTED) {
// Permission is not granted
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
Manifest.permission.CALL_PHONE)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
} else {
// No explanation needed; request the permission
ActivityCompat.requestPermissions(thisActivity,
new String[]{Manifest.permission.CALL_PHONE},
MY_PERMISSIONS_REQUEST_CALL_PHONE);
// MY_PERMISSIONS_REQUEST_CALL_PHONE is an
// app-defined int constant. The callback method gets the
// result of the request.
}
} else {
// Permission has already been granted
}
Verifying:
#Override
public void onRequestPermissionsResult(int requestCode,
String[] permissions, int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_CALL_PHONE: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, yay! Do the
// contacts-related task you need to do.
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
}
return;
}
// other 'case' lines to check for other
// permissions this app might request.
}
}

You can do via Intent
public void dialClick (View v) {
phone = edtPhone.getText().toString();
Uri uri = Uri.parse("tel: " + phone);
it = new Intent(Intent.ACTION_DIAL);
it.setData(uri);
startActivity(it);
}

You need to add the permissions at run time to be able to make the call, I recommend the following library, since it is much easier to implement the permissions in time of execution.
https://github.com/Karumi/Dexter

Writing to external storage?

I have written codes from the tutorials of SLIDENERD to save info in different areas as internal cache,External cache,Private information and public information with the following codes.
EditText uname,pwd;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
uname=(EditText)findViewById(R.id.editText);
pwd=(EditText)findViewById(R.id.editText3);
}
public void intCache(View view){
File fileDir=getCacheDir();
File myFile=new File(fileDir,"User_info_intCache.txt");
write(myFile);
}
public void extCache(View view){
File fileDir=getExternalCacheDir();
File myFile=new File(fileDir,"User_info_extCache.txt");
write(myFile);
}
public void pvtDir(View view){
File fileDir=getExternalFilesDir("User_Info");
File myFile=new File(fileDir,"User_info_pvtExt.txt");
write(myFile);
}
public void pubDir(View view){
File fileDir= Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
File myFile=new File(fileDir,"User_info_pubExt.txt");
write(myFile);
}
private void write(File myFile){
String unameS=uname.getText().toString();
String pwdS=pwd.getText().toString();
FileOutputStream fileOutputStream=null;
try {
fileOutputStream=new FileOutputStream(myFile);
try {
fileOutputStream.write(unameS.getBytes());
fileOutputStream.write(pwdS.getBytes());
} catch (IOException e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
finally {
try {
if (fileOutputStream != null) {
fileOutputStream.close();
}
Toast.makeText(this,"data is written to "+myFile.getAbsolutePath(),Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
}
}
}
I can see the files user_info_extCache.txt , User_info_pvtExt.txt. I know that internal cache location ( User_info_intCache.txt ) cant be seen.But i can't find the User_info_pubExt.txt file which must be stored in public directory Downloads.I cant see the file created by following code.
File fileDir= Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
File myFile=new File(fileDir,"User_info_pubExt.txt");
The toast shows that the file is created by above piece of code under /storage/emulated/0/Download/User_info_pubExt.txt .
I find somewhere that if phone is connected to pc,external storage cant be accessed.So i tried both by removing the mobile from pc.The toast says that file is created.But i cant find it under that folder.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.iamka.storage">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".Main2Activity"></activity>
</application>

Your toast claiming that data is written is on the wrong place. As the toast also displays when there is an exception.
Place the toast in the try block instead. Or yet better after the close() but only if you close().
And place other toasts in the catch blocks to inform the user with e.getMessage().
As for the exception: all the paths exept the last one do not need any read/write permission at all. For the latter you need read/write permission.
But requesting them in manifest is not enough for Android 6+ as then you have to add some code to ask the user to confirm the requested permissions.
Google for runtime permissions.

Requesting Runtime Permissions Causes Crash

The main reason I'm posting here is that I'm currently stuck without a computer that can run an emulator, I've been having to send the APK to my phone to test it. Even if my phone's connected to my computer, or I have a third party emulator running, it wont work. Due to this...I have no error logs.
The app is a simple password manager, and all the other functions thus far work. I was trying to add an export function, I can't get either to actually write anything. I've checked other questions and various sources online, but I cannot seem to figure out what could be causing it. When the method is called, it simply doesn't do anything as far as I can tell. I apologize if I'm missing something, or if there was indeed another question with the same issue. I couldn't find anything missing.
Here is the method I'm using;
EDIT: The code has been updated to reflect a better method of requesting runtime permissions, which was suggested here. This ultimately is what fixed the application.
//Method017: Exports the account info to a .txt file.
public void exportData() throws IOException {
//Opens dialog to request permission.
ActivityCompat.requestPermissions(Main.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
}
//Method to handle result of permission request.
#Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case 1: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//Attempt to write a file to the Download folder.
String content = "hello world";
File file;
FileOutputStream outputStream;
try {
file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), "MyCache");
outputStream = new FileOutputStream(file);
outputStream.write(content.getBytes());
outputStream.close();
//According to an online source, this is necessary to make the file viewable on the device.
Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
intent.setData(Uri.fromFile(file));
sendBroadcast(intent);
} catch (IOException e) {
e.printStackTrace();
}
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
Toast.makeText(Main.this, "Permission denied to read your External storage", Toast.LENGTH_SHORT).show();
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
And my manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.brand.psync">
<application
android:allowBackup="true"
android:icon="#drawable/psynclogo"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme"
android:screenOrientation="portrait">
<activity android:name=".Main">
<intent-filter>
<action
android:name="android.intent.action.MAIN"
android:screenOrientation="portrait" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<category
android:name="android.intent.category.LAUNCHER"
android:screenOrientation="portrait" />
</intent-filter>
</activity>
</application>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
</manifest>
Sorry about the lack of error log...but if I had that, I likely wouldn't need to post here.

I have try your code and it working.
public class SaveFileSampleActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TextView lblBackground = new TextView(this);
lblBackground.setBackgroundColor(Color.WHITE);
setContentView(lblBackground);
ActivityCompat.requestPermissions(SaveFileSampleActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
}
#Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode) {
case 1: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//Attempt to write a file to the Download folder.
String content = "hello world";
File file;
FileOutputStream outputStream;
try {
file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), "MyCache");
outputStream = new FileOutputStream(file);
outputStream.write(content.getBytes());
outputStream.close();
//According to an online source, this is necessary to make the file viewable on the device.
Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
intent.setData(Uri.fromFile(file));
sendBroadcast(intent);
} catch (IOException e) {
e.printStackTrace();
}
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
Toast.makeText(SaveFileSampleActivity.this, "Permission denied to read your External storage", Toast.LENGTH_SHORT).show();
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
}
And mainifest
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".SaveFileSampleActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
It's work and result:
You can review your code. I hope it can help you!

Android: How to check if a file exists on my sdcard

I'm trying to check if a file exists on my sdcard with this code but I have some problems. The API version on my Android phone is 19 and the API version of the application is 19 but there are a lot of exceptions from other application which I do not want to work with like zedge for example. Please give me some hints on how to check if that file exists.
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
File extStore = Environment.getExternalStorageDirectory();
File myFile = new File(extStore.getAbsolutePath() + "/test.txt");
if(myFile.exists()){
Log.d("File", "exists");
}
}
public boolean isExternalStorage() {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
return true;
}
return false;
}
}
My Manifest file is like this:
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

your code just checks if file exists at sdcard/fileName.ext :
File extStore = Environment.getExternalStorageDirectory();
File myFile = new File(extStore.getAbsolutePath() + "/test.txt");
if(myFile.exists()){
Log.d("File", "exists");
}
To search entire file system (dir tree), we need a recursive function which enters a directory or compares a file with search file name:
public static boolean searchForFile(File root, File mySearchFile)
{
if(root == null || mySearchFile == null) return; //just for safety
if(root.isDirectory())
{
Boolean flag = false;
for(File file : root.listFiles()){
flag = searchForDatFiles(file, mySearchFile);
if(flag) return true;
}
}
else if(root.isFile() && root.getName().equals(mySearchFile.getName())
{
return true;
}
return false;
}
UPDATE
Just saw that you are looking for the file in root folder only. Check this link for four ways to check if file exists. Also, above code will work for sdcard only too, but not recommended because it will parse any folders it first encounter. Good for whole directory tree search.

How to open a PDF file from in-app browser?

I have a basic File Browser inside my app and I want it to be able to open PDF files, but for some reason, even though I can tap on the PDF files and they open for a second, they go away and my phone gives a Toast message with an error, and this Toast I haven't programmed anywhere in my code. This is weird because the same PDF file opens from my other activities without any issues. (See the OpenPDF() Method which works from my PDFManager class) I researched a lot about how to fix this but couldn't find a clear answer. Thanks for helping!
The toast error: Cannot display PDF (filename.pdf cannot be opened)
OnListItemClick function from AndroidFileBrowser:
#Override
protected void onListItemClick(ListView l, View v, int position, long id) {
String filename = (String) getListAdapter().getItem(position);
if (path.endsWith(File.separator)) {
filename = path + filename;
} else {
filename = path + File.separator + filename;
}
pdf = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getPath() + "/PATH/" + filename);
Uri path = Uri.fromFile(pdf);
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
intent.setDataAndType(path, "application/pdf");
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
try {
startActivity(intent);
} catch (ActivityNotFoundException e) {
e.printStackTrace();
}
}
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.faraz.pdfreader"
xmlns:android="http://schemas.android.com/apk/res/android">
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme"
>
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
<activity
android:name=".SimpleScannerActivity"
android:label="#string/simple_scanner_activity"
android:theme="#style/AppOverlayTheme">
</activity>
<activity android:name=".PDFManager"/>
<activity android:name=".AndroidFileBrowser"/>
<!--android:screenOrientation="portrait"-->
</application>
</manifest>
OpenPDF() method from my PDFManager class
public void openPDF() {
File pdf = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getPath() + "/PATH/" + pdfname + ".pdf");
if (pdf.exists()) {
Uri path = Uri.fromFile(pdf);
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
intent.setDataAndType(path, "application/pdf");
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
try {
startActivity(intent);
} catch (ActivityNotFoundException e) {
Toast.makeText(PDFManager.this,
"No application available to view PDF!",
Toast.LENGTH_SHORT).show();
/* Intent intent = new Intent(Intent.ACTION_VIEW)
.setData(Uri.parse("http://docs.google.com/gview?embedded=true&url=" + url));
startActivity(intent);
}
*/
}
}
}
}

In your OnItemClick():
if (path.endsWith(File.separator))
{
filename = path + filename;
}
else
{
filename = path + File.separator + filename;
}
pdf = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getPath() + "/PATH/" + filename);
Uri path = Uri.fromFile(pdf);
You use "path" before you initialize it, so depending on your intentions either change the name of one or the other, or declare it before your if-statement not after.