Replace server Guava API usage with Android compatible alternatives.

The issue occurs when the Android flavor of Guava somehow finds its way onto the processor class path and gets classloaded instead of the server Guava. The ideal solution would be to just keep the Android flavor of Guava off of the processor class path. However, it's been something that we've allowed for a while now, e.g. in Dagger, and would be difficult to start enforcing.

This CL adds a new API for auto-common. A follow-up CL will update auto-value and auto-service to depend on the new auto-common APIs once auto-common has a release with those changes.

RELNOTES=Added new public APIs for guava collector usage (toImmutable*) that are Android-compatible.
PiperOrigin-RevId: 376892205

3 files changed, 77 insertions, 2 deletions

diff --git a/common/src/main/java/com/google/auto/common/AnnotationValues.java b/common/src/main/java/com/google/auto/common/AnnotationValues.java
index a5db2cca..296bacd1 100644
--- a/common/src/main/java/com/google/auto/common/AnnotationValues.java
+++ b/common/src/main/java/com/google/auto/common/AnnotationValues.java
@@ -15,8 +15,8 @@
  */
 package com.google.auto.common;
 
+import static com.google.auto.common.MoreStreams.toImmutableList;
 import static com.google.common.base.Preconditions.checkNotNull;
-import static com.google.common.collect.ImmutableList.toImmutableList;
 
 import com.google.common.base.Equivalence;
 import com.google.common.collect.ImmutableList;
diff --git a/common/src/main/java/com/google/auto/common/MoreStreams.java b/common/src/main/java/com/google/auto/common/MoreStreams.java
new file mode 100644
index 00000000..934514ab
--- /dev/null
+++ b/common/src/main/java/com/google/auto/common/MoreStreams.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.auto.common;
+
+import static java.util.stream.Collectors.collectingAndThen;
+import static java.util.stream.Collectors.toList;
+
+import com.google.common.collect.ImmutableBiMap;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Maps;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collector;
+import java.util.stream.Collectors;
+
+/**
+ * A utility class that provides Android compatible alternatives to Guava's streaming APIs.
+ *
+ * <p>This is useful when the Android flavor of Guava somehow finds its way onto the processor
+ * classpath.
+ */
+public final class MoreStreams {
+
+  /** Returns a collector for an {@link ImmutableList}. */
+  public static <T> Collector<T, ?, ImmutableList<T>> toImmutableList() {
+    return collectingAndThen(toList(), ImmutableList::copyOf);
+  }
+
+  /** Returns a collector for an {@link ImmutableSet}. */
+  public static <T> Collector<T, ?, ImmutableSet<T>> toImmutableSet() {
+    return collectingAndThen(toList(), ImmutableSet::copyOf);
+  }
+
+  /** Returns a collector for an {@link ImmutableMap}. */
+  public static <T, K, V> Collector<T, ?, ImmutableMap<K, V>> toImmutableMap(
+      Function<? super T, K> keyMapper, Function<? super T, V> valueMapper) {
+    return Collectors.mapping(
+        value -> Maps.immutableEntry(keyMapper.apply(value), valueMapper.apply(value)),
+        Collector.of(
+            ImmutableMap::builder,
+            (ImmutableMap.Builder<K, V> builder, Map.Entry<K, V> entry) -> builder.put(entry),
+            (left, right) -> left.putAll(right.build()),
+            ImmutableMap.Builder::build));
+  }
+
+  /** Returns a collector for an {@link ImmutableBiMap}. */
+  public static <T, K, V> Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(
+      Function<? super T, K> keyMapper, Function<? super T, V> valueMapper) {
+    return Collectors.mapping(
+        value -> Maps.immutableEntry(keyMapper.apply(value), valueMapper.apply(value)),
+        Collector.of(
+            ImmutableBiMap::builder,
+            (ImmutableBiMap.Builder<K, V> builder, Map.Entry<K, V> entry) -> builder.put(entry),
+            (left, right) -> left.putAll(right.build()),
+            ImmutableBiMap.Builder::build));
+  }
+
+  private MoreStreams() {}
+}
diff --git a/common/src/main/java/com/google/auto/common/SimpleAnnotationMirror.java b/common/src/main/java/com/google/auto/common/SimpleAnnotationMirror.java
index 7d508e32..bbaf8fc9 100644
--- a/common/src/main/java/com/google/auto/common/SimpleAnnotationMirror.java
+++ b/common/src/main/java/com/google/auto/common/SimpleAnnotationMirror.java
@@ -16,8 +16,8 @@
 
 package com.google.auto.common;
 
+import static com.google.auto.common.MoreStreams.toImmutableMap;
 import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.collect.ImmutableMap.toImmutableMap;
 import static javax.lang.model.util.ElementFilter.methodsIn;
 
 import com.google.common.base.Joiner;