Update code and docs for minimum Android API level 24

README.md

@@ -69,6 +69,7 @@ see [`GsonBuilder.disableJdkUnsafe()`](https://javadoc.io/doc/com.google.code.gs
 
 #### Minimum Android API level
 
+- Gson 2.15.0 and newer: API level 24
 - Gson 2.11.0 and newer: API level 21
 - Gson 2.10.1 and older: API level 19
 

gson/src/main/java/com/google/gson/internal/NonNullElementWrapperList.java

@@ -19,9 +19,11 @@
 import java.util.AbstractList;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Objects;
 import java.util.RandomAccess;
+import java.util.Spliterator;
 
 /**
  * {@link List} which wraps another {@code List} but prevents insertion of {@code null} elements.
@@ -117,6 +119,16 @@ public <T> T[] toArray(T[] a) {
     return delegate.toArray(a);
   }
 
+  @Override
+  public void sort(Comparator<? super E> c) {
+    delegate.sort(c);
+  }
+
+  @Override
+  public Spliterator<E> spliterator() {
+    return delegate.spliterator();
+  }
+
   @Override
   public boolean equals(Object o) {
     return delegate.equals(o);
@@ -126,7 +138,4 @@ public boolean equals(Object o) {
   public int hashCode() {
     return delegate.hashCode();
   }
-
-  // Maybe also delegate List#sort and List#spliterator in the future, but that
-  // requires Android API level 24
 }

gson/src/main/java/com/google/gson/internal/bind/TypeAdapters.java

@@ -16,6 +16,8 @@
 
 package com.google.gson.internal.bind;
 
+import static java.lang.Math.toIntExact;
+
 import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonIOException;
@@ -903,15 +905,6 @@ long[] integerValues(Calendar calendar) {
         }
       };
 
-  // TODO: update this when we are on at least Android API Level 24.
-  private static int toIntExact(long x) {
-    int i = (int) x;
-    if (i != x) {
-      throw new IllegalArgumentException("Too big for an int: " + x);
-    }
-    return i;
-  }
-
   public static final TypeAdapterFactory CALENDAR_FACTORY =
       newFactoryForMultipleTypes(Calendar.class, GregorianCalendar.class, CALENDAR);
 

pom.xml

@@ -523,7 +523,7 @@
               <configuration>
                 <skip>${gson.isTestModule}</skip>
                 <signature>
-                  <!-- Google's internal use currently requires API Level 23 without desugaring. -->
+                  <!-- Don't use https://github.com/open-toast/gummy-bears; Google's internal use currently does not support desugaring. -->
                   <groupId>net.sf.androidscents.signature</groupId>
                   <artifactId>android-api-level-24</artifactId>
                   <version>7.0_r2</version>