Fix lint/pmd/findbugs errors.

library/src/main/java/com/bumptech/glide/load/DecodeFormat.java

@@ -27,7 +27,7 @@ public enum DecodeFormat {
 
   /**
    * Identical to {@link #PREFER_ARGB_8888} but prevents Glide from using {@link
-   * android.graphics.Bitmap.Config#HARDWARE} on Android O+
+   * android.graphics.Bitmap.Config#HARDWARE} on Android O+.
    *
    * @deprecated If you must disable hardware bitmaps, set
    * {@link com.bumptech.glide.load.resource.bitmap.Downsampler#ALLOW_HARDWARE_CONFIG} to false

library/src/main/java/com/bumptech/glide/load/engine/DecodeJob.java

@@ -478,7 +478,9 @@ class DecodeJob<R> implements DataFetcherGenerator.FetcherReadyCallback,
     Options options = getOptionsWithHardwareConfig(dataSource);
     DataRewinder<Data> rewinder = glideContext.getRegistry().getRewinder(data);
     try {
-      return path.load(rewinder, options, width, height, new DecodeCallback<>(dataSource));
+      // ResourceType in DecodeCallback below is required for compilation to work with gradle.
+      return path.load(
+          rewinder, options, width, height, new DecodeCallback<ResourceType>(dataSource));
     } finally {
       rewinder.cleanup();
     }

library/src/main/java/com/bumptech/glide/load/engine/bitmap_recycle/LruBitmapPool.java

@@ -142,16 +142,23 @@ public class LruBitmapPool implements BitmapPool {
     return result;
   }
 
-  @Nullable
-  private synchronized Bitmap getDirtyOrNull(int width, int height, Bitmap.Config config) {
+  @TargetApi(Build.VERSION_CODES.O)
+  private static void assertNotHardwareConfig(Bitmap.Config config) {
     // Avoid short circuiting on sdk int since it breaks on some versions of Android.
-    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-      if (config == Bitmap.Config.HARDWARE) {
-        throw new IllegalArgumentException("Cannot create a mutable Bitmap with config: " + config
-            + ". Consider setting Downsampler#ALLOW_HARDWARE_CONFIG to false in your RequestOptions"
-            + " and/or in GlideBuilder.setDefaultRequestOptions");
-      }
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
+      return;
     }
+
+    if (config == Bitmap.Config.HARDWARE) {
+      throw new IllegalArgumentException("Cannot create a mutable Bitmap with config: " + config
+          + ". Consider setting Downsampler#ALLOW_HARDWARE_CONFIG to false in your RequestOptions"
+          + " and/or in GlideBuilder.setDefaultRequestOptions");
+    }
+  }
+
+  @Nullable
+  private synchronized Bitmap getDirtyOrNull(int width, int height, Bitmap.Config config) {
+    assertNotHardwareConfig(config);
     // Config will be null for non public config types, which can lead to transformations naively
     // passing in null as the requested config here. See issue #194.
     final Bitmap result = strategy.get(width, height, config != null ? config : DEFAULT_CONFIG);

library/src/main/java/com/bumptech/glide/load/resource/bitmap/Downsampler.java

@@ -194,8 +194,8 @@ public final class Downsampler {
     DecodeFormat decodeFormat = options.get(DECODE_FORMAT);
     DownsampleStrategy downsampleStrategy = options.get(DOWNSAMPLE_STRATEGY);
     boolean fixBitmapToRequestedDimensions = options.get(FIX_BITMAP_SIZE_TO_REQUESTED_DIMENSIONS);
-    boolean isHardwareConfigAllowed = options.get(ALLOW_HARDWARE_CONFIG) != null
-        ? options.get(ALLOW_HARDWARE_CONFIG) : false;
+    boolean isHardwareConfigAllowed =
+      options.get(ALLOW_HARDWARE_CONFIG) != null && options.get(ALLOW_HARDWARE_CONFIG);
     if (decodeFormat == DecodeFormat.PREFER_ARGB_8888_DISALLOW_HARDWARE) {
       isHardwareConfigAllowed = false;
     }

library/src/main/java/com/bumptech/glide/load/resource/bitmap/HardwareConfigState.java

 package com.bumptech.glide.load.resource.bitmap;
 
+import android.annotation.TargetApi;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.os.Build;
@@ -70,6 +71,7 @@ final class HardwareConfigState {
     // Singleton constructor.
   }
 
+  @TargetApi(Build.VERSION_CODES.O)
   boolean setHardwareConfigIfAllowed(
       int targetWidth,
       int targetHeight,