GeezerVison is showing javaevolved.dev — Multi-catch exception handling | java.evolved

Home / Errors / Multi-catch exception handling

Errors Beginner

Multi-catch exception handling

Catch multiple exception types in a single catch block.

Code Comparison

✕ Pre-Java 7

try {
    process();
} catch (IOException e) {
    log(e);
} catch (SQLException e) {
    log(e);
} catch (ParseException e) {
    log(e);
}

✓ Java 7+

try {
    process();
} catch (IOException
    | SQLException
    | ParseException e) {
    log(e);
}

Share 𝕏

See a problem with this code? Let us know.

Why the modern way wins

📏

DRY

Same handling logic written once instead of three times.

🔄

Rethrowable

The caught exception can be rethrown with its precise type.

📖

Scannable

All handled types are visible in one place.

Old Approach

Separate Catch Blocks

Modern Approach

Multi-catch

Since JDK

Difficulty

Beginner

JDK Support

Multi-catch exception handling

Available

Widely available since JDK 7 (July 2011)

How it works

Multi-catch handles multiple exception types with the same code. The exception variable is effectively final, so you can rethrow it without wrapping.

Null case in switch

Java 8

// Must check before switch
if (status == null) {
    return "unknown";
}
return switch (status) {
    case ACTIVE  -> "active";
    case PAUSED  -> "paused";
    default      -> "other";
};

Java 21+

return switch (status) {
    case null    -> "unknown";
    case ACTIVE  -> "active";
    case PAUSED  -> "paused";
    default      -> "other";
};

Hover to see modern ➜

JDK 21+ →

Errors Beginner

Helpful NullPointerExceptions

Java 8

// Old NPE message:
// "NullPointerException"
// at MyApp.main(MyApp.java:42)
// Which variable was null?!

Java 14+

// Modern NPE message:
// Cannot invoke "String.length()"
// because "user.address().city()"
// is null
// Exact variable identified!

Hover to see modern ➜

JDK 14+ →

Errors Beginner

Objects.requireNonNullElse()

Java 8

String name = input != null
    ? input
    : "default";
// easy to get the order wrong

Java 9+

String name = Objects
    .requireNonNullElse(
        input, "default"
    );

Hover to see modern ➜

JDK 9+ →