Application
Programming
Hend Alkittawi

Debugging
How To Debug Java Code and Android
Applications

DEBUGGING ANDROID APPLICATIONS
-

Some of the problems you may
encounter while building android
applications. The application may
crash at runtime or not function as
expected!

-

As an IDE, Android Studio has some
tools to help developers debug their
code. These tools are:
-

The Logcat

-

Android Lint

-

The Debugger

THE LOGCAT
-

When an application is running, the Logcat tool window
provides access to diagnostic messages.

-

The log output displays messages which are created using the
Log class
-

The syntax to create a log diagnostic message is
Log.[logLevelInitial]("TAG", "Message")

-

Some of the available log levels:
-

Information, Verbose, Debug, Error

-

the log level and the tag helps with filtering messages

-

Example: Log.d("PeekActivity", "Button Clicked!")

THE LOGCAT

ANDROID LINT
-

Android Lint is a static analyzer for Android code
-

a program that examines your code to find defects without
running it

-

Android Lint is aware of the Android framework components and
and can find problems that the compiler cannot find.

-

For example, it is good for finding issues in XML files.

-

To run Android Lint: Code > Inspect Code the click Analyze

ANDROID LINT

THE DEBUGGER
-

The debugger is a tool mainly used to run the application under
controlled conditions that permit the developer to track its
execution and monitor changes in computer resources that may
indicate malfunctioning code.

-

To control the application execution, add breakpoints to your
code lines.

-

A breakpoint next to a line of code pauses the execution before
the line executes and allows you to examine what happens next.

-

To run the application in debug-mode, add breakpoint(s) then
Run > Debug

THE DEBUGGER
-

When using the debugger, the developer can control the app execution:
-

Step Into
-

A method is about to be invoked, and you want to debug into the code of that
method, so the next step is to go into that method and continue debugging
step-by-step.

-

Step Over
-

A method is about to be invoked, but you're not interested in debugging this
particular invocation, so you want the debugger to execute that method completely
as one entire step.

-

Step Return
-

You're done debugging this method step-by-step, and you just want the debugger to
run the entire method until it returns as one entire step.

-

Resume
-

You want the debugger to resume "normal" execution instead of step-by-step

p

THE DEBUGGER

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3. Control execution

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DEBUGGING ANDROID APPLICATIONS
-

When errors persist, some things you can try
-

Recheck the xml in resource files

-

Clean the project build

-

-

Build > Clean Project

-

Android studio will rebuild the project from scratch

Clean the project
-

File > Invalidate Caches/Restart

-

Android Studio will perform some maintenance on the project
and restart itself

-

Check online :)

CODE DEMO
-

Show the different
tools in Android
Studio.

DO YOU HAVE ANY
QUESTIONS?

THANK
YOU!

@

hend.alkittawi@utsa.edu
By Appointment
Online