merge GuavaCollectors into Collectors and rename methods

4 files changed, 109 insertions, 169 deletions

diff --git a/sonar-core/src/main/java/org/sonar/core/util/stream/Collectors.java b/sonar-core/src/main/java/org/sonar/core/util/stream/Collectors.java
index bbe096f0ff0..e13d3c14271 100644
--- a/sonar-core/src/main/java/org/sonar/core/util/stream/Collectors.java
+++ b/sonar-core/src/main/java/org/sonar/core/util/stream/Collectors.java
@@ -19,6 +19,8 @@
  */
 package org.sonar.core.util.stream;
 
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
@@ -32,38 +34,96 @@ public final class Collectors {
   }
 
   /**
-   * Delegates to {@link java.util.stream.Collectors#toList()}.
+   * A Collector into an {@link ImmutableList}.
    */
-  public static <T> Collector<T, ?, List<T>> toList() {
-    return java.util.stream.Collectors.toList();
+  public static <T> Collector<T, List<T>, List<T>> toList() {
+    return Collector.of(
+      ArrayList::new,
+      List::add,
+      (left, right) -> {
+        left.addAll(right);
+        return left;
+      },
+      ImmutableList::copyOf);
+  }
+
+  /**
+   * A Collector into an {@link ImmutableList} of the specified expected size.
+   */
+  public static <T> Collector<T, List<T>, List<T>> toList(int expectedSize) {
+    // use ArrayList rather than ImmutableList.Builder because initial capacity of builder can not be specified
+    return Collector.of(
+      () -> new ArrayList<>(expectedSize),
+      List::add,
+      (left, right) -> {
+        left.addAll(right);
+        return left;
+      },
+      ImmutableList::copyOf);
+  }
+
+  /**
+   * A Collector into an {@link ImmutableSet}.
+   */
+  public static <T> Collector<T, Set<T>, Set<T>> toSet() {
+    return Collector.of(
+      HashSet::new,
+      Set::add,
+      (left, right) -> {
+        left.addAll(right);
+        return left;
+      },
+      ImmutableSet::copyOf);
+  }
+
+  /**
+   * A Collector into an {@link ImmutableSet} of the specified expected size.
+   */
+  public static <T> Collector<T, Set<T>, Set<T>> toSet(int expectedSize) {
+    // use HashSet rather than ImmutableSet.Builder because initial capacity of builder can not be specified
+    return Collector.of(
+      () -> new HashSet<>(expectedSize),
+      Set::add,
+      (left, right) -> {
+        left.addAll(right);
+        return left;
+      },
+      ImmutableSet::copyOf);
+  }
+
+  /**
+   * Delegates to {@link java.util.stream.Collectors#toCollection(Supplier)}.
+   */
+  public static <T> Collector<T, ?, ArrayList<T>> toArrayList() {
+    return java.util.stream.Collectors.toCollection(ArrayList::new);
   }
 
   /**
    * Does {@code java.util.stream.Collectors.toCollection(() -> new ArrayList<>(size));} which is equivalent to
-   * {@link #toList()} but avoiding array copies when the size of the resulting set is already known.
+   * {@link #toArrayList()} but avoiding array copies when the size of the resulting list is already known.
    *
    * @see java.util.stream.Collectors#toList()
    * @see java.util.stream.Collectors#toCollection(Supplier)
    */
-  public static <T> Collector<T, ?, List<T>> toList(int size) {
+  public static <T> Collector<T, ?, ArrayList<T>> toArrayList(int size) {
     return java.util.stream.Collectors.toCollection(() -> new ArrayList<>(size));
   }
 
   /**
-   * Delegates to {@link java.util.stream.Collectors#toSet()}.
+   * Delegates to {@link java.util.stream.Collectors#toCollection(Supplier)}.
    */
-  public static <T> Collector<T, ?, Set<T>> toSet() {
-    return java.util.stream.Collectors.toSet();
+  public static <T> Collector<T, ?, HashSet<T>> toHashSet() {
+    return java.util.stream.Collectors.toCollection(HashSet::new);
   }
 
   /**
    * Does {@code java.util.stream.Collectors.toCollection(() -> new HashSet<>(size));} which is equivalent to
-   * {@link #toSet()} but avoiding array copies when the size of the resulting set is already known.
+   * {@link #toHashSet()} but avoiding array copies when the size of the resulting set is already known.
    *
    * @see java.util.stream.Collectors#toSet()
    * @see java.util.stream.Collectors#toCollection(Supplier)
    */
-  public static <T> Collector<T, ?, Set<T>> toSet(int size) {
+  public static <T> Collector<T, ?, HashSet<T>> toHashSet(int size) {
     return java.util.stream.Collectors.toCollection(() -> new HashSet<>(size));
   }
 }
diff --git a/sonar-core/src/main/java/org/sonar/core/util/stream/GuavaCollectors.java b/sonar-core/src/main/java/org/sonar/core/util/stream/GuavaCollectors.java
deleted file mode 100644
index 700c570c542..00000000000
--- a/sonar-core/src/main/java/org/sonar/core/util/stream/GuavaCollectors.java
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- * SonarQube
- * Copyright (C) 2009-2016 SonarSource SA
- * mailto:contact AT sonarsource DOT com
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 3 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
- */
-package org.sonar.core.util.stream;
-
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableSet;
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.stream.Collector;
-
-public final class GuavaCollectors {
-  private GuavaCollectors() {
-    // prevents instantiation
-  }
-
-  /**
-   * A Collector into an {@link ImmutableList}.
-   */
-  public static <T> Collector<T, List<T>, ImmutableList<T>> toList() {
-    return Collector.of(
-      ArrayList::new,
-      List::add,
-      (left, right) -> {
-        left.addAll(right);
-        return left;
-      },
-      ImmutableList::copyOf);
-  }
-
-  /**
-   * A Collector into an {@link ImmutableList} of the specified expected size.
-   */
-  public static <T> Collector<T, List<T>, ImmutableList<T>> toList(int expectedSize) {
-    // use ArrayList rather than ImmutableList.Builder because initial capacity of builder can not be specified
-    return Collector.of(
-      () -> new ArrayList<>(expectedSize),
-      List::add,
-      (left, right) -> {
-        left.addAll(right);
-        return left;
-      },
-      ImmutableList::copyOf);
-  }
-
-  /**
-   * A Collector into an {@link ImmutableSet}.
-   */
-  public static <T> Collector<T, Set<T>, ImmutableSet<T>> toSet() {
-    return Collector.of(
-      HashSet::new,
-      Set::add,
-      (left, right) -> {
-        left.addAll(right);
-        return left;
-      },
-      ImmutableSet::copyOf);
-  }
-
-  /**
-   * A Collector into an {@link ImmutableSet} of the specified expected size.
-   */
-  public static <T> Collector<T, Set<T>, ImmutableSet<T>> toSet(int expectedSize) {
-    // use HashSet rather than ImmutableSet.Builder because initial capacity of builder can not be specified
-    return Collector.of(
-      () -> new HashSet<>(expectedSize),
-      Set::add,
-      (left, right) -> {
-        left.addAll(right);
-        return left;
-      },
-      ImmutableSet::copyOf);
-  }
-
-}
diff --git a/sonar-core/src/test/java/org/sonar/core/util/stream/CollectorsTest.java b/sonar-core/src/test/java/org/sonar/core/util/stream/CollectorsTest.java
index e3bd3c1b101..a8c02735f51 100644
--- a/sonar-core/src/test/java/org/sonar/core/util/stream/CollectorsTest.java
+++ b/sonar-core/src/test/java/org/sonar/core/util/stream/CollectorsTest.java
@@ -19,6 +19,8 @@
  */
 package org.sonar.core.util.stream;
 
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
@@ -30,27 +32,57 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 public class CollectorsTest {
   @Test
-  public void toList_builds_an_ArrayList() {
+  public void toList_builds_an_ImmutableList() {
     List<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(Collectors.toList());
-    assertThat(res).isInstanceOf(ArrayList.class)
+    assertThat(res).isInstanceOf(ImmutableList.class)
       .containsExactly(1, 2, 3, 4, 5);
   }
+
   @Test
-  public void toList_with_size_builds_an_ArrayList() {
+  public void toList_with_size_builds_an_ImmutableList() {
     List<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(Collectors.toList(30));
-    assertThat(res).isInstanceOf(ArrayList.class)
+    assertThat(res).isInstanceOf(ImmutableList.class)
       .containsExactly(1, 2, 3, 4, 5);
   }
 
   @Test
-  public void toSet_builds_an_HashSet() {
+  public void toSet_builds_an_ImmutableSet() {
     Set<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(Collectors.toSet());
-    assertThat(res).isInstanceOf(HashSet.class)
+    assertThat(res).isInstanceOf(ImmutableSet.class)
       .containsExactly(1, 2, 3, 4, 5);
   }
+
   @Test
-  public void toSet_with_size_builds_an_ArrayList() {
+  public void toSet_with_size_builds_an_ImmutableSet() {
     Set<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(Collectors.toSet(30));
+    assertThat(res).isInstanceOf(ImmutableSet.class)
+      .containsExactly(1, 2, 3, 4, 5);
+  }
+
+  @Test
+  public void toArrayList_builds_an_ArrayList() {
+    List<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(Collectors.toArrayList());
+    assertThat(res).isInstanceOf(ArrayList.class)
+      .containsExactly(1, 2, 3, 4, 5);
+  }
+
+  @Test
+  public void toArrayList_with_size_builds_an_ArrayList() {
+    List<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(Collectors.toArrayList(30));
+    assertThat(res).isInstanceOf(ArrayList.class)
+      .containsExactly(1, 2, 3, 4, 5);
+  }
+
+  @Test
+  public void toHashSet_builds_an_HashSet() {
+    Set<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(Collectors.toHashSet());
+    assertThat(res).isInstanceOf(HashSet.class)
+      .containsExactly(1, 2, 3, 4, 5);
+  }
+
+  @Test
+  public void toHashSet_with_size_builds_an_ArrayList() {
+    Set<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(Collectors.toHashSet(30));
     assertThat(res).isInstanceOf(HashSet.class)
       .containsExactly(1, 2, 3, 4, 5);
   }
diff --git a/sonar-core/src/test/java/org/sonar/core/util/stream/GuavaCollectorsTest.java b/sonar-core/src/test/java/org/sonar/core/util/stream/GuavaCollectorsTest.java
deleted file mode 100644
index 2ff0c28fb6a..00000000000
--- a/sonar-core/src/test/java/org/sonar/core/util/stream/GuavaCollectorsTest.java
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * SonarQube
- * Copyright (C) 2009-2016 SonarSource SA
- * mailto:contact AT sonarsource DOT com
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 3 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
- */
-package org.sonar.core.util.stream;
-
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableSet;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Set;
-import org.junit.Test;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-public class GuavaCollectorsTest {
-  @Test
-  public void toList_builds_an_ImmutableList() {
-    List<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(GuavaCollectors.toList());
-    assertThat(res).isInstanceOf(ImmutableList.class)
-        .containsExactly(1, 2, 3, 4, 5);
-  }
-  @Test
-  public void toList_with_size_builds_an_ImmutableList() {
-    List<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(GuavaCollectors.toList(30));
-    assertThat(res).isInstanceOf(ImmutableList.class)
-        .containsExactly(1, 2, 3, 4, 5);
-  }
-
-  @Test
-  public void toSet_builds_an_ImmutableSet() {
-    Set<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(GuavaCollectors.toSet());
-    assertThat(res).isInstanceOf(ImmutableSet.class)
-        .containsExactly(1, 2, 3, 4, 5);
-  }
-  @Test
-  public void toSet_with_size_builds_an_ImmutableSet() {
-    Set<Integer> res = Arrays.asList(1, 2, 3, 4, 5).stream().collect(GuavaCollectors.toSet(30));
-    assertThat(res).isInstanceOf(ImmutableSet.class)
-        .containsExactly(1, 2, 3, 4, 5);
-  }
-
-
-}