Prerequisites

• Ensure the Android SDK is installed and your Android development environment is fully configured.
• Confirm the Android plugin is enabled in IntelliJ IDEA, and connect a physical Android device or launch an emulator to establish a connection.

Debugging Steps

Setting Breakpoints

To set a breakpoint, either right-click the gutter adjacent to the target code line and select "Toggle Breakpoint", or use the Ctrl+F8 keyboard shortcut to quickly toggle breakpoints on the current line.

Launch Debug Mode

Start a debug session by navigating to the "Run" menu and selecting "Debug", or use the Shift+F9 keyboard shortcut to initiate debugging mode.

Debugging the Application

In debug mode, utilize a range of tools to diagnose issues: inspect real-time variable values, execute code line-by-line (step into, over, or out), skip breakpoints, and more to efficiently isolate and resolve bugs.

Troubleshooting Example: Travel App Navigation Issue

Suppose you’re building a travel planning app and encounter an issue: after selecting a destination and tapping the "Confirm" button, the app fails to navigate to the next screen. Debugging points to a potential flaw in the click event handler for the confirmation button.

Here’s a snippet of the relevant code under investigation:

public void onConfirmDestinationClicked(View view) {
    String selectedLocation = destinationInput.getText().toString().trim();
    if (selectedLocation.isEmpty()) {
        Toast.makeText(this, "Please enter or select a valid destination", Toast.LENGTH_SHORT).show();
    } else {
        Intent navigationIntent = new Intent(this, TripDetailsActivity.class);
        navigationIntent.putExtra("selected_destination", selectedLocation);
        startActivity(navigationIntent);
    }
}

Set a breakpoint at the start of the onConfirmDestinationClicked method and launch the debug session. When you tap the "Confirm" button, the debugger will pause at the breakpoint. Use step-through debugging to inspect the selectedLocation value, verify the Intent initialization, and check if the startActivity call executes as expected. This process helps you identify exactly where the navigation flow breaks—for example, if the input has unintended whitespace that bypasses validation, or if the Intent target activity isn’t registered in the manifest.

Travel App Debugging Workflow

journey
    title Travel App Debugging Workflow
    section Set Breakpoints
        Developer configures breakpoints in target code
    section Launch Debug Session
        Developer initiates debug mode in IDE
    section Diagnose and Fix Issue
        Developer uses debug tools to isolate and resolve the bug