Method Chaining

1. We have two versions of a method that checks conditions on a deeply nested object structure.

Version 1: Repeated method chains

private boolean isRequestNotValidated(PaymentValidationRequest paymentValidationRequest) {
    return paymentValidationRequest.getPayment().getPaymentType().equals(TRANSFER)
        &&
        paymentValidationRequest.getPayment().getTransferTransactionInformation().getAdditions()
            .get(SESSION_ID)
            == null
        && !hashGenerator.generateValidationHash(requestDataUtils.getShortCIF()).equals(
        paymentValidationRequest.getPayment().getTransferTransactionInformation().getAdditions()
            .get(VALIDATION_HASH));
}

Version 2: Intermediate variable for reuse

private boolean isRequestNotValidated(PaymentValidationRequest paymentValidationRequest) {
    var additions = paymentValidationRequest.getPayment().getTransferTransactionInformation().getAdditions();

    return paymentValidationRequest.getPayment().getPaymentType().equals(TRANSFER)
        &&
        additions.get(SESSION_ID) == null
        && !hashGenerator.generateValidationHash(requestDataUtils.getShortCIF()).equals(
        additions.get(VALIDATION_HASH));
}

Version 2 is better for the following reasons:

1. Readability

• Extracting intermediate results (additions) improves readability and reduces mental load.

• Readers only need to understand the logic of the condition, not how it’s fetched every time.

2. Maintainability

• If the method chain changes, we only have to update it in one place.

• Prevents errors from inconsistent calls.

3. Performance

• No noticeable performance difference in most cases.

• JVM performs common subexpression elimination and method inlining during Just-In-Time (JIT) compilation.

• Repeated chains may result in slightly more bytecode but won’t affect runtime efficiency significantly — if the getter methods are cheap (simple field accesses).

But if:

• The getters are doing more than returning a value (e.g., performing logic or expensive computation),

• Or they involve reflection, network calls, or dynamic proxies (common in some frameworks),

Then repeated calls could degrade performance.

So while JVM might optimize it, don't depend on it for correctness or speed — extracting to a variable is the cleaner and safer approach.

Null Safety

With repeated method calls, it’s easy to accidentally get a NullPointerException if any level in the chain is null.

Extracting intermediate variables allows:

• Easier null-checks

• Optional usage

• Better error messages and logging