Develop Reference

Android ContentResolver.getType is not ready when app starts

I'm getting an issue where ContentResolver.getType is not ready when the app starts.
However, putting a delay of 1s, will make it ready.
Code:
String mimeType = contentResolver.getType(uri); // returns null
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
String mimeType2 = contentResolver.getType(uri); // returns correct mime type
Note this only happens on app startup.
Any help is highly appreciated.
Thanks.

How do I see Android logs that were logged before connecting to Android studio

Is there a way to see Android logs that were logged before connecting to the Android Studio?
I have an app that tracks GPS location. The issue is that it terminates after some time and I get the Android system message that says "Application Terminated"
I want to see what went wrong and where. When I connect Android studio later, it shows logs that happened from time it is connected.
I want the logs from past.

There are couple of things you can try to resolve:
1) I generally write logs when I have such cases to test.
public static void writeToFile(String msg) {
Log.d("MyApp", msg);
try {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
FileOutputStream dio = null;
File file = new File(Environment.getExternalStorageDirectory(), "MyApp_File_Logs.txt");
if (file != null) {
try {
dio = new FileOutputStream(file, true);
dio.write((msg+"\n").getBytes());
dio.close();
dio = null;
} catch (Exception e) {
e.printStackTrace();
}
}
}
} catch (Exception e) {
Log.e("MyApp", "Exception in writeToFile(): " + e.getMessage());
}
}
So instead of Log.d , Use this Utility method. You can add time in the message to be more precise.
Done forget to give write external storage permission to you app
2) Once you see crash , go to command prompt
and use the below commands:
adb shell
logcat -b crash
You might see something in this, if you connect within a minute or so
3) Increase the "Logger Buffer Size " in your developer options , but in this case you will see delay in getting logs when you connect your device to adb and open logcat.

you can add a log module into your app,let log module output your app's log into local file,like logger

Connecting my app to local network using smb protocol

I'm trying to connect my Android application to my company local network (Windows) using smb protocol. The problem is I'm kinda newbie on this matter and something is missing me.
The goal is download the file AREQA.txt from the network to the device. However I don't even can verify if the code can trace the file location because the application crashes when I compile it to the device (it loads fine but crashes when I call the DownLoadF001 procedure). Here's the code:
public void DownLoadF001(View v) {
jcifs.Config.registerSmbURLHandler();
String user;
String password;
String filename;
File localFile;
SmbFile path = null;
try {
NtlmPasswordAuthentication auth = new NtlmPasswordAuthentication(null,"######", "********");
path = new SmbFile("smb:\\192.168.1.11/.../AREQA.txt", auth);
try {
if(path.exists()){
Toast.makeText(getApplicationContext(), "Sucesso!", Toast.LENGTH_LONG).show();
}
} catch (Exception e1) {
Toast.makeText(getApplicationContext(), e1.toString(), Toast.LENGTH_LONG).show();
}
} catch (MalformedURLException e2) {
Toast.makeText(getApplicationContext(), e2.toString(), Toast.LENGTH_LONG).show();
}
}
I already tried to remove the inside try from the main one (with all its associated code), and the application stops crashing. However, without it, I can't see if the connection is working.
EDIT: I managed to catch the error (Exception e1):
java.lang.NullPointerException: Attempt to invoke virtual method int java.lang.String.length()' on a null object reference. Any ideas to solve it?
Also, as pointed by #greenapps, I'm calling this procedure from a .xml button by onClick method.

how to send report to Acralyzer manual

I am using Acralyzer for reporting of errors (Crash reports)
Now I want to manually send a Custom report to Acra.
But do not know , how to do ?

Try this:
try
{
// some code
}
catch (Exception e) {
ErrorReporter.getInstance().handleException(e);
}

Need some explaining

So this is the weirdest thing ever to happen to me during programing. Yes I'm no pro at programing, but I'm learning as I go. I've got an app talking to a server, a socket in the main thread, reading is done in a separate class and thread and writing in a separate class with asynctask.
The problem is LocationManager. I could talk to server and write/read commands just fine, I implemented the LocationManager and its listener.
I then proceeded to implement a method to update my textview with the new coordinates on locatinChanged. So far so good. Thing is when I use the Emulator control in eclipse and send coordinates the app crashed with a stringOutOfBoundsException (I've programed for 3 years now never seen this). I looked at the code stepped through it and so on. Read the stacktrace, logcat, console and everywhere I could think of but it got me nowhere. Until I finally went to the readerthread which looks like this:
public class ReaderThread extends Thread {
public void run() {
new Thread(new Runnable(){
public void run(){
try {
//Establish a bufferedreader to read from the socket/server.
in = new BufferedReader(new InputStreamReader(socket.getInputStream()), 8 * 1024);
}
catch(Exception e) { e.printStackTrace(); }
//As long as connect is true.
while (connected) {
String line;
try {
//Try to read a line from the reader.
line = in.readLine();
System.out.println(in.readLine());
if (in == null) {
//No one has sent a message yet.
System.out.println("No data recieved");
}
else {
int i = 0;
//As long as someone is sending messages.
while((line = in.readLine()) != null ){
//Make a new Message.
Message msg;
msg = new Message();
//Set the object to the input line.
msg.obj = line;
//Set an id so it can be identified in the main class and used in a switch.
msg.what = i;
System.out.println("i is: "+i);
//Send the message to the handler.
Main.this.h.sendMessage(msg);
}
}
}
catch (Exception e) {
System.out.println(e.getMessage());
}
}
}
}).start();
}
The variable i is in an if statement depending on what the server sent but I cut that out as it has nothing to do with this problem.
The problem is the freaking catch. When the catch is IOException, the app crashes. Out of dumb luck I changed this to Exception and printed e.message to catch the error and see what caused it. Thing is this change fixed it. How can switching IOException to just plain Exception fix a problem like this?
Its like with IOException the program says: "hey your not gonna catch the error but there is no error" but with Exception it says "Well now you could catch it so I'll proceed".
My app is working but I just can't grasp this, why and how does this happen?

You're essentially telling the application to catch the base Exception class. This means that any type of error will be caught, since all exception classes descend from that base type. Since StringOutOfBoundsException does not descend from IOException it was not being caught before and the error was not being caught. Instead of catching all exceptions, you might try the following:
try {
// Your code here...
} catch (IOException e) {
Log.e(TAG, "Caught an IOException!", e);
} catch (StringOutOfBoundsException e) {
Log.e(TAG, "Caught a string out of bounds Exception!", e);
}
I'm unable to determine what is actually throwing the StringOutOfBoundsException to begin with. It may be in the if statement that you cut out of your example.

while (connected) {
String line;
try {
//Try to read a line from the reader.
line = in.readLine();
System.out.println(in.readLine());
if (in == null) {
//No one has sent a message yet.
System.out.println("No data recieved");
}
The test for in == null is in a funny location. You should receive a NullPointerException if that test were to ever return true by nature of calling methods on it a few lines earlier. Obviously something is a little funny with this code.
You fail to save the return value from in.readLine() the second time you call it. I hope it did not contain anything useful. (Though, since you print the line, you obviously wanted to know what data it contained.)
Whatever that line was (from the first call to in.readLine()), it gets thrown away; there's nothing else in the loop that uses it before it is over-written on this line:
while((line = in.readLine()) != null ){
At this point, the two lines that you read are gone forever.
I'm not entirely sure what should be done to fix this; if it were me, I'd be sorely tempted to start over with a sheet of paper and sketch out what the method should be doing without looking at the existing code, then compare the sketch against the code to see which cases each one has overlooked.