不支持 Try_catch 块 android 工作室语言级别 8？

Question

I am making an app in Android Studio:

public class MainActivity extends AppCompatActivity {

    SharedPreferences sharedPreferences;
    EditText noteTitleField, noteContentField;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        sharedPreferences = getSharedPreferences("NoteAppPrefs", Context.MODE_PRIVATE);
        String setValueInPrefs = sharedPreferences.getString("alreadyLaunched", null);
        try (setValueInPrefs.equals("0")) {
            Log.d("debugging", "App running for first time... launching setup");
            setupForFirstTime();
        } catch (NullPointerException e) {
            noteContentField = findViewById(R.id.noteContentTextBox);
            noteTitleField = findViewById(R.id.noteTitleTextBox);
            Toast.makeText(MainActivity.this, R.string.welcomeMessage, Toast.LENGTH_LONG);
        }
    }
}

However, I am getting "Resource References are not supported at language level 8".

I checked some threads like this one intellij feature (...) not supported at this language level. I can't compile to figure out where the error could be coming from but I checked both Project JDK versions and Android Studio JRE and they match on "java version 1.8"

Thank you for helping

Answer 1

The line

try (setValueInPrefs.equals("0")) {

is not valid. In Java 8 code code in the parentheses must be an assignment statement ( VariableDeclaratorId = Expression ) and

The type of a variable declared in a resource specification must be a subtype of AutoCloseable, or a compile-time error occurs.

Java 9 relaxed the part with the assignment statement (now it can also be a variable or a field), but still

The type of a variable declared or referred to as a resource in a resource specification must be a subtype of AutoCloseable, or a compile-time error occurs.

You are using setValueInPrefs.equals("0") as expression, which results in a boolean value and boolean is not a subtype of AutoCloseable.

To fix it you should replace the try block with

    if (setValueInPrefs != null) {
        if (setValueInPrefs.equals("0")) {
            Log.d("debugging", "App running for first time... launching setup");
            setupForFirstTime();
        }
    } else {
        noteContentField = findViewById(R.id.noteContentTextBox);
        noteTitleField = findViewById(R.id.noteTitleTextBox);
        Toast.makeText(MainActivity.this, R.string.welcomeMessage, Toast.LENGTH_LONG);
    }