API Level 24+ Methods Used with minSdkVersion 21

Severity: HIGH — D93795294 fixed build failure; related SEV S311353 was production crash

What to Look For

• Java 8 Stream APIs: .stream(), .parallelStream(), .collect()
• Map methods: computeIfAbsent(), putIfAbsent(), getOrDefault(), forEach()
• Comparator methods: Comparator.naturalOrder(), Comparator.reverseOrder()
• Stream.of(), Collectors.toList()

When to Flag

• Any of the above APIs used in code with minSdkVersion < 24
• Missing @RequiresApi or @TargetApi annotation with version guard
• No fallback implementation for API 21-23 devices

Do NOT Flag

• Code inside if (Build.VERSION.SDK_INT >= 24) blocks
• Code with @RequiresApi(24) annotation AND version guard
• Kotlin stdlib equivalents (.map {}, .filter {})
• Test code that only runs on API 24+ devices

Examples

// BAD — parallelStream requires API 24+
items.parallelStream()
    .map { transform(it) }
    .collect(Collectors.toList())  // ❌ Crashes on API 21-23

// GOOD — Kotlin stdlib works on all API levels
items.map { transform(it) }  // ✅ Safe

// BAD — naturalOrder requires API 24+
Queue<Long> heap = new PriorityQueue<>(Comparator.naturalOrder());  // ❌

// GOOD — Custom comparator works on all APIs
Queue<Long> heap = new PriorityQueue<>(capacity,
    (t1, t2) -> Long.compare(t1, t2));  // ✅ Safe

Recommendation

For Fresco (minSdk 21):

1. Never use .stream() or .parallelStream()
2. Never use Comparator.naturalOrder() or reverseOrder()
3. Always use Kotlin stdlib (map, filter) or manual loops

Evidence

• D93795294: parallelStream() in iterativeBlurBoxFilter.kt broke gradle build
• SEV S311353: Production crash from Comparator.naturalOrder() (API 24+)