Develop Reference

Retrofit not returning any response

I am trying to use RetroFit Synchronus call to connect and fetch data to one of my APIs.
try{
RestAdapter restAdapter = new RestAdapter.Builder().setEndpoint(finalUri.toString()).build();
IGooglePlacesApi iGPlaceApi = restAdapter.create(IGooglePlacesApi.class);
mGooglePlacesApiResponse googlePlacesObj = iGPlaceApi.getStreams();
RetrofitError retrofitError;
} catch (IOException e) {
serverResponse = e.getMessage();
} catch (IllegalArgumentException e) {
serverResponse = e.getMessage();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
Log.d("serverResponse:", serverResponse);
}
Which is declared here as:
public interface IGooglePlacesApi {
#GET("/stream/list.json")
mGooglePlacesApiResponse getStreams();
}
Issue is when i call iGPlaceApi.getStreams(); i dont get a result neither any error. But my code just directly goes to the finally block?
Why this is happening, no result, no catch. How can i correct this?

Retrofit wraps all internal exceptions into a RetrofitError exception and throws that. In your case you're not catching that exception therefore only the finally block is executed.
Try modifying your code this way,
try {
RestAdapter restAdapter = new RestAdapter.Builder().setEndpoint(finalUri.toString()).build();
IGooglePlacesApi iGPlaceApi = restAdapter.create(IGooglePlacesApi.class);
mGooglePlacesApiResponse googlePlacesObj = iGPlaceApi.getStreams();
} catch (RetrofitError e) {
serverResponse = e.getMessage();
} finally {
Log.d("serverResponse:", serverResponse);
}
The RetrofitError thrown depending on the failure will contain the exception cause or the status reported by the server. You can then apply the necessary logic from there.
For more general purposes error handling you can set an ErrorHandler when creating your RestAdapter. This ErrorHandler will be executed before you catch the RetrofitError in your try/catch.

Android Reflection - Android Jars

Case 1: Look at the code below. I am able to get Class and Method objects and it works well. Method I am trying to access is android.view.View::dispatchPointerEvent.
Case 2: When I replace class/Method with com.android.server.pm.PackageManagerService::grantPermissionsLPw, I get NoMethodFoundException. Class was accessible though.
Case 3: When I replace class/Method with android.hardware.input.InputManager::injectInputEvent, I get NoMethodFoundException. Class was accessible though.
Question is: Why some of the android class/methods are accessible via reflection and some other not?
Class _class = null;
try {
_class = Class.forName("android.view.View");
Log.i("Test", "Class found");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
Method method = null;
try {
Log.i("Test", "Pre-Method found");
method = _class.getDeclaredMethod("dispatchPointerEvent",
MotionEvent.class);
Log.i("Test", "Method found");
} catch (Exception e) {
Log.i("Test","I failed."+e.getMessage()+e.toString());
//e.printStackTrace();
}

Try this
Class _class = null;
try {
_class = Class.forName("com.android.server.pm.PackageManagerService");
Log.i("Test", "Class found");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
Method method = null;
try {
Log.i("Test", "Pre-Method found");
Class _class2 = Class.forName("android.content.pm.PackageParser$Package");
method = _class.getDeclaredMethod("grantPermissionsLPw",
_class2, boolean.class);
Log.i("Test", "Method found");
} catch (Exception e) {
Log.i("Test","I failed."+e.getMessage()+e.toString());
e.printStackTrace();
}

(Sorry but I cannot post comments, so have to post response)
Did you put the right method parameters? Where you have MotionEvent.class.

android.hardware.input.InputManager::injectInputEvent requires the android.permission.INJECT_EVENTS permission which is a system permission not available to apps. If you need to do this you'll have to root the device and sign your app as a system app.

Android Internal Object Storage

I am trying to save ArrayLists(ArrayOne, ArrayTwo, and ArrayThree) of EditText's to the internal storage. As commented, it clearly shows that it attempts the save, but I never get another TOAST after that. Any help as of why it doesn't show "Save completed" or any error is appreciated.
public void save(Context c)
{
String fileName;
Toast.makeText(this, "Attempting Save", Toast.LENGTH_SHORT).show();//THIS SHOWS
if(semester.getText().toString().length() == 0)
{
Toast.makeText(c, "Please enter a filename", Toast.LENGTH_SHORT).show();
}
else
{
fileName = "test.dat";
FileOutputStream fos = null;
ObjectOutputStream oos = null;
try
{
fos = this.openFileOutput(fileName, Context.MODE_PRIVATE);
oos = new ObjectOutputStream(fos);
oos.writeObject(ArrayOne);
oos.writeObject(ArrayTwo);
oos.writeObject(ArrayThree);
Toast.makeText(c, "Save Completed", Toast.LENGTH_SHORT).show(); //THIS NEVER SHOWS
}
catch (FileNotFoundException e)
{
Toast.makeText(c, "Could not find " + fileName + " to save.", Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
finally
{
try
{
if (oos != null)
oos.close();
if (fos != null)
fos.close();
}
catch (Exception e)
{ /* do nothing */ }
}
}
}

The problem is that the EditText class is not serializable
If you debug and put a break point at on the printStackTrace and examine the IOException it will tell you that
catch (IOException e
{
e.printStackTrace();
}
Classes have to use "implements Serializable" in order for them to be written out as objects, which EditText does not have.
You can not extend the class and add the serializable tag either because the underlying class will still throw the exception.
I suggest you either serialize the data via your own class or save whatever you are trying to do with some other method.

I think the error is beings swallowed in your first Try block because you're only catching FileNotFound and IOException - just for debugging purposes you could catch the generic Exception and printout the stacktrace.
If it also helps this is what I do:
java.io.File file = new java.io.File("/sdcard/mystorage/ArrayOne.bin");
ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream(file)));
out.writeObject(obj);
out.close();
Best
-serkan

If nothing shows after the "Attempting save" you´re getting some exception in this block
catch (IOException e)
{
e.printStackTrace();
}
And you´re not viewing it in any Toast. Also you can be here in this way doing nothing with your exception:
catch (Exception e)
{ /* do nothing */ }
Instead of toasting your messages.. try to use LogCat for debbugging, is easy to use and also you don't need to put toast code in your code. Tell me how is going.

Android: Any shortcut to Serializable from Parcelable without using marshall()?

I'm aware of the performance differences between Parcelable (fast) and Serializable (slow). However, I need to store certain application information persistently, not just within one lifecycle, thus onSaveInstanceState and associated methods utilising Parcelable objects aren't appropriate.
So I turned my attention to Serializable. Primarily I have AbstractList types to store - which is fine, since they implement Serializable. However, many of the types I store inside these are Parcelable but not Serializable, e.g. RectF.
I thought "no problem", since I can easily generate a Parcel via Parcelable.writeToParcel(parcel, flags) then call marshall() on it to create a byte[] which I can serialize and deserialize. I figured I'd use generics; create a SerializableParcelable<Parcelable> implements Serializable class, allowing a one-fit solution for all Parcelable types I wish to serialize. Then I would e.g. store each RectF inside this wrapper within ArrayList, and lo-and-behold the list and its Parcelable contents are serializable.
However, the API docs state that marshall() mustn't be used for persistent storage:
public final byte[] marshall ()
Returns the raw bytes of the parcel.
The data you retrieve here must not be placed in any kind of persistent storage (on local disk, across a network, etc). For that, you should use standard serialization or another kind of general serialization mechanism. The Parcel marshalled representation is highly optimized for local IPC, and as such does not attempt to maintain compatibility with data created in different versions of the platform.
So now I'm stuck. I can either ignore this warning and follow the route I've outlined above, or else circumvent the issue by extending each individual Parcelable I want to serialize and creating bespoke serialization methods, which seems extremely wasteful of time and effort.
Does anyone know of a 'correct' shortcut to serialize a Parcelable object without using marshall()? Or should I plough on without heeding the warning specified? Perhaps an SQLite database is the way to go, but I'm unsure and would like your advice.
Many thanks.

For any object you need to serialize you can use objectOutPutStream .By using this you can write objects into the file system of the device.So this can used to save Parcelable objects also.
Below is the code to save object to File System.
public static void witeObjectToFile(Context context, Object object, String filename) {
ObjectOutputStream objectOut = null;
FileOutputStream fileOut = null;
try {
File file = new File(filename);
if(!file.exists()){
file.createNewFile();
}
fileOut = new FileOutputStream(file,false);
objectOut = new ObjectOutputStream(fileOut);
objectOut.writeObject(object);
fileOut.getFD().sync();
} catch (IOException e) {
e.printStackTrace();
} catch (NullPointerException e) {
e.printStackTrace();
}finally {
if (objectOut != null) {
try {
objectOut.close();
} catch (IOException e) {
// do nowt
}
}
if (fileOut != null) {
try {
fileOut.close();
} catch (IOException e) {
// do nowt
}
}
}
}`
Inorder to read the Object use ObjectInputStream . Find the below code.
public static Object readObjectFromFile(Context context, String filename) {
ObjectInputStream objectIn = null;
Object object = null;
FileInputStream fileIn = null;
try {
File file = new File(filename);
fileIn = new FileInputStream(file);//context.getApplicationContext().openFileInput(filename);
objectIn = new ObjectInputStream(fileIn);
object = objectIn.readObject();
} catch (FileNotFoundException e) {
// Do nothing
}catch (NullPointerException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}finally {
if (objectIn != null) {
try {
objectIn.close();
} catch (IOException e) {
// do nowt
}
}
if(fileIn != null){
try {
fileIn.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return object;
}`
Regards,
Sha

Android - print full exception backtrace to log

I have a try/catch block that throws an exception and I would like to see information about the exception in the Android device log.
I read the log of the mobile device with this command from my development computer:
/home/dan/android-sdk-linux_x86/tools/adb shell logcat
I tried this first:
try {
// code buggy code
} catch (Exception e)
{
e.printStackTrace();
}
but that doesn't print anything to the log. That's a pity because it would have helped a lot.
The best I have achieved is:
try {
// code buggy code
} catch (Exception e)
{
Log.e("MYAPP", "exception: " + e.getMessage());
Log.e("MYAPP", "exception: " + e.toString());
}
Better than nothing but not very satisfying.
Do you know how to print the full backtrace to the log?
Thanks.

try {
// code that might throw an exception
} catch (Exception e) {
Log.e("MYAPP", "exception", e);
}
More Explicitly with Further Info
(Since this is the oldest question about this.)
The three-argument Android log methods will print the stack trace for an Exception that is provided as the third parameter. For example
Log.d(String tag, String msg, Throwable tr)
where tr is the Exception.
According to this comment those Log methods "use the getStackTraceString() method ... behind the scenes" to do that.

This helper function also works nice since Exception is also a Throwable.
try{
//bugtastic code here
}
catch (Exception e)
{
Log.e(TAG, "Exception: "+Log.getStackTraceString(e));
}

catch (Exception e) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PrintStream stream = new PrintStream( baos );
e.printStackTrace(stream);
stream.flush();
Log.e("MYAPP", new String( baos.toByteArray() );
}
Or... ya know... what EboMike said.

public String getStackTrace(Exception e){
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
e.printStackTrace(pw);
return sw.toString();
}

e.printStackTrace() prints it to me. I don't think you're running the logcat correctly. Don't run it in a shell, just run
/home/dan/android-sdk-linux_x86/tools/adb logcat

The standard output and error output are directed to /dev/null by default so it is all lost. If you want to log this output then you need to follow the instructions "Viewing stdout and stderr" shown here

try{
...
} catch (Exception e) {
Log.e(e.getClass().getName(), e.getMessage(), e.getCause());
}

if you want to print out stack trace without exception, you can create it by following command
(new Throwable()).printStackTrace();

In the context of Android, I had to cast the Exception to a String:
try {
url = new URL(REGISTRATION_PATH);
urlConnection = (HttpURLConnection) url.openConnection();
} catch(MalformedURLException e) {
Log.i("MALFORMED URL", String.valueOf(e));
} catch(IOException e) {
Log.i("IOException", String.valueOf(e));
}

KOTLIN SOLUTION:
You can make use of the helper function getStackTraceString() belonging to the android.util.Log class to print the entire error message on console.
Example:
try {
// your code here
} catch (e: Exception) {
Log.e("TAG", "Exception occurred, stack trace: " + e.getStackTraceString());
}

Kotlin extension. Returns the detailed description of this throwable with its stack trace.
e.stackTraceToString()