【设计模式】建造者模式——Glide源码中的建造者模式

建造者模式在Glide源码中的应用是比较广泛的

GlideBuilder

Glide源码中最典型的建造者模式就是GlideBuilder类：

/** A builder class for setting default structural classes for Glide to use. */
@SuppressWarnings("PMD.ImmutableField")
public final class GlideBuilder {
  // ……代码省略……

  @NonNull
  public GlideBuilder setBitmapPool(@Nullable BitmapPool bitmapPool) {
    this.bitmapPool = bitmapPool;
    return this;
  }

  @NonNull
  public GlideBuilder setArrayPool(@Nullable ArrayPool arrayPool) {
    this.arrayPool = arrayPool;
    return this;
  }

  @SuppressWarnings("WeakerAccess")
  @NonNull
  public GlideBuilder setMemoryCache(@Nullable MemoryCache memoryCache) {
    this.memoryCache = memoryCache;
    return this;
  }

  @SuppressWarnings("WeakerAccess")
  @NonNull
  public GlideBuilder setDiskCache(@Nullable DiskCache.Factory diskCacheFactory) {
    this.diskCacheFactory = diskCacheFactory;
    return this;
  }

  @SuppressWarnings("WeakerAccess")
  @NonNull
  public GlideBuilder setSourceExecutor(@Nullable GlideExecutor service) {
    this.sourceExecutor = service;
    return this;
  }

  @SuppressWarnings("WeakerAccess")
  @NonNull
  public GlideBuilder setDiskCacheExecutor(@Nullable GlideExecutor service) {
    this.diskCacheExecutor = service;
    return this;
  }
  
  @SuppressWarnings("unused")
  @NonNull
  public GlideBuilder setLogLevel(int logLevel) {
    if (logLevel < Log.VERBOSE || logLevel > Log.ERROR) {
      throw new IllegalArgumentException(
          "Log level must be one of Log.VERBOSE, Log.DEBUG," + " Log.INFO, Log.WARN, or Log.ERROR");
    }
    this.logLevel = logLevel;
    return this;
  }
  
  // ……代码省略……

  @NonNull
  Glide build(
      @NonNull Context context,
      List<GlideModule> manifestModules,
      AppGlideModule annotationGeneratedGlideModule) {
    
    // ……代码省略……

    return new Glide(
        context,
        engine,
        memoryCache,
        bitmapPool,
        arrayPool,
        requestManagerRetriever,
        connectivityMonitorFactory,
        logLevel,
        defaultRequestOptionsFactory,
        defaultTransitionOptions,
        defaultRequestListeners,
        manifestModules,
        annotationGeneratedGlideModule,
        experiments);
  }

  // ……代码省略……
}