How to perform performance optimization in Android and what are the common tools

Performance optimization is a core skill in Android development, involving multiple dimensions including memory, UI, network, and battery.

1. Memory Optimization

Memory Leak Detection

• LeakCanary: Automatic memory leak detection
• Android Profiler: Real-time memory allocation monitoring
• MAT: Analyze hprof files, find dominator tree

Memory Optimization Strategies

kotlin
// 1. Use SparseArray instead of HashMap<Integer, Object>
val sparseArray = SparseArray<String>()

// 2. Image memory optimization
val options = BitmapFactory.Options().apply {
    inSampleSize = 2  // Scale sampling
    inBitmap = reusableBitmap  // Bitmap reuse
}

// 3. Use LRU cache
val cache = LruCache<String, Bitmap>(maxMemory / 8)

Large Image Optimization

• Use inSampleSize compression
• Use WebP format
• Use image loading libraries (Glide, Picasso, Coil)

2. UI Rendering Optimization

Layout Optimization

xml
<!-- 1. Reduce layout hierarchy -->
<merge>  <!-- Reduce one ViewGroup layer -->
<include>  <!-- Reuse layout -->
<ViewStub>  <!-- Lazy loading -->

Avoid Overdraw

kotlin
// 1. Remove unnecessary backgrounds
window.setBackgroundDrawable(null)

// 2. Use clipRect to reduce drawing area
canvas.clipRect(left, top, right, bottom)

List Optimization

kotlin
// RecyclerView optimization
recyclerView.setHasFixedSize(true)
recyclerView.setItemViewCacheSize(20)
recyclerView.setRecycledViewPool(pool)

3. Network Optimization

Request Optimization

kotlin
// 1. Use connection pool
okHttpClient.connectionPool(ConnectionPool(5, 5, TimeUnit.MINUTES))

// 2. Enable Gzip compression
okHttpClient.addInterceptor(GzipInterceptor())

// 3. Set reasonable timeouts
okHttpClient.connectTimeout(10, TimeUnit.SECONDS)

Data Caching

kotlin
// 1. Use Cache-Control
@Headers("Cache-Control: max-age=3600")

// 2. Local cache strategy
val cache = Cache(cacheDir, 10 * 1024 * 1024)  // 10MB

4. Battery Optimization

Doze Mode and App Standby

• Understand system power saving mechanisms
• Use high-priority FCM messages
• Batch background tasks

Background Task Optimization

kotlin
// Use WorkManager instead of background Service
val constraints = Constraints.Builder()
    .setRequiredNetworkType(NetworkType.CONNECTED)
    .setRequiresBatteryNotLow(true)
    .build()

val workRequest = PeriodicWorkRequestBuilder<SyncWorker>(1, TimeUnit.HOURS)
    .setConstraints(constraints)
    .build()

Location Optimization

kotlin
// Use balanced accuracy mode
locationRequest.priority = LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY

// Remove location updates promptly
fusedLocationClient.removeLocationUpdates(callback)

5. Package Size Optimization

Resource Optimization

groovy
android {
    // 1. Remove unused resources
    lintOptions {
        checkReleaseBuilds false
    }
    
    // 2. Resource compression
    shrinkResources true
    minifyEnabled true
    
    // 3. Keep only specific languages
    resConfigs "zh", "en"
}

Code Optimization

groovy
// 1. Use ProGuard/R8 obfuscation
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt')

// 2. Dynamic feature modules
android {
    dynamicFeatures = [':feature1', ':feature2']
}

6. Startup Optimization

• Async initialization
• Lazy loading non-essential components
• Use SplashScreen API

7. Common Performance Analysis Tools

Tool	Purpose	Usage Scenario
Android Profiler	CPU/Memory/Network monitoring	Real-time app performance monitoring
Systrace	System-level performance analysis	Analyze frame rate, startup time
Layout Inspector	Layout hierarchy analysis	Optimize layout nesting
GPU Overdraw	Overdraw detection	Optimize drawing performance
LeakCanary	Memory leak detection	Detect leaks during development
StrictMode	Violation detection	Detect main thread IO, etc.
Battery Historian	Battery analysis	Analyze power consumption

8. Systrace Usage Example

bash
# Capture trace
python systrace.py -a com.example -o trace.html sched gfx view

# Analysis focus
# 1. Check frame rate (Frame) for dropped frames
# 2. Check if UI thread is blocked
# 3. Check GC frequency

9. Performance Optimization Checklist

• Test performance in Release mode
• Verify on low-end devices
• Monitor online performance data
• Regular performance regression testing
• Establish performance baseline metrics

Key Points

• Master common memory optimization methods
• Understand UI rendering principles and optimization methods
• Familiar with usage of various performance analysis tools
• Understand best practices for battery optimization
• Master APK slimming technical solutions