Create an "internals" package for classes that we do not want to share, but is needed across multiple pacakges.

As well, move non-Gson specific classes, such as Preconditions, to this new "internals" package.

gson/src/main/java/com/google/gson/CamelCaseSeparatorNamingPolicy.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Type;
 import java.util.Collection;

gson/src/main/java/com/google/gson/DefaultTypeAdapters.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Types;
+
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.math.BigDecimal;

gson/src/main/java/com/google/gson/DelegatingJsonElementVisitor.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 import java.io.IOException;
 
 /**

gson/src/main/java/com/google/gson/DisjunctionExclusionStrategy.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 import java.util.Collection;
 
 /**

gson/src/main/java/com/google/gson/FieldAttributes.java

@@ -16,6 +16,11 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Cache;
+import com.google.gson.internal.LruCache;
+import com.google.gson.internal.Pair;
+import com.google.gson.internal.Preconditions;
+
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
 import java.lang.reflect.Type;

gson/src/main/java/com/google/gson/FieldNamingStrategy2Adapter.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 /**
  * Adapts the old "deprecated" FieldNamingStrategy to the new {@link FieldNamingStrategy2}
  * type. 

gson/src/main/java/com/google/gson/Gson.java

@@ -16,6 +16,7 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Primitives;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonToken;
 import com.google.gson.stream.JsonWriter;

gson/src/main/java/com/google/gson/GsonBuilder.java

@@ -27,6 +27,7 @@ import java.util.Map;
 import java.util.Set;
 
 import com.google.gson.DefaultTypeAdapters.DefaultDateTypeAdapter;
+import com.google.gson.internal.Preconditions;
 
 /**
  * <p>Use this builder to construct a {@link Gson} instance when you need to set configuration

gson/src/main/java/com/google/gson/JsonArrayDeserializationVisitor.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Types;
+
 import java.lang.reflect.Array;
 import java.lang.reflect.Type;
 

gson/src/main/java/com/google/gson/JsonDeserializationVisitor.java

@@ -16,6 +16,9 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Pair;
+import com.google.gson.internal.Preconditions;
+
 import java.lang.reflect.Type;
 
 /**

gson/src/main/java/com/google/gson/JsonDeserializerExceptionWrapper.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 import java.lang.reflect.Type;
 
 /**

gson/src/main/java/com/google/gson/JsonFieldNameValidator.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 

gson/src/main/java/com/google/gson/JsonObject.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 import java.io.IOException;
 import java.util.LinkedHashMap;
 import java.util.Map;

gson/src/main/java/com/google/gson/JsonObjectDeserializationVisitor.java

@@ -16,6 +16,9 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Pair;
+import com.google.gson.internal.Primitives;
+
 import java.lang.reflect.Type;
 
 /**

gson/src/main/java/com/google/gson/JsonPrimitive.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 import java.io.IOException;
 import java.math.BigDecimal;
 import java.math.BigInteger;

gson/src/main/java/com/google/gson/JsonSerializationContextDefault.java

@@ -16,6 +16,7 @@
 
 package com.google.gson;
 
+
 import java.lang.reflect.Type;
 
 /**

gson/src/main/java/com/google/gson/JsonSerializationVisitor.java

@@ -16,6 +16,10 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Pair;
+import com.google.gson.internal.Preconditions;
+import com.google.gson.internal.Types;
+
 import java.lang.reflect.Array;
 import java.lang.reflect.Type;
 
@@ -168,7 +172,7 @@ final class JsonSerializationVisitor implements ObjectNavigator.Visitor {
   /**
    * objTypePair.getObject() must not be null
    */
-  @SuppressWarnings({"unchecked", "rawtypes"})
+  @SuppressWarnings("unchecked")
   private JsonElement findAndInvokeCustomSerializer(ObjectTypePair objTypePair) {
     Pair<JsonSerializer<?>,ObjectTypePair> pair = objTypePair.getMatchingHandler(serializers);
     if (pair == null) {

gson/src/main/java/com/google/gson/MapTypeAdapter.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Types;
+
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.util.LinkedHashMap;

gson/src/main/java/com/google/gson/MappedObjectConstructor.java

@@ -16,6 +16,9 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Types;
+import com.google.gson.internal.UnsafeAllocator;
+
 import java.lang.reflect.Array;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Type;

gson/src/main/java/com/google/gson/MemoryRefStack.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 import java.util.Stack;
 
 /**

gson/src/main/java/com/google/gson/ModifyFirstLetterNamingPolicy.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Type;
 import java.util.Collection;

gson/src/main/java/com/google/gson/ObjectNavigator.java

@@ -16,6 +16,10 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+import com.google.gson.internal.Primitives;
+import com.google.gson.internal.Types;
+
 import java.lang.reflect.AccessibleObject;
 import java.lang.reflect.Field;
 import java.lang.reflect.Type;

gson/src/main/java/com/google/gson/ObjectNavigatorFactory.java

@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Preconditions;
+
 /**
  * A factory class used to simplify {@link ObjectNavigator} creation.
  * This object holds on to a reference of the {@link ExclusionStrategy}

gson/src/main/java/com/google/gson/ObjectTypePair.java

@@ -15,6 +15,8 @@
  */
 package com.google.gson;
 
+import com.google.gson.internal.Pair;
+
 import java.lang.reflect.Type;
 
 /**

gson/src/main/java/com/google/gson/ParameterizedTypeHandlerMap.java

@@ -16,6 +16,9 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Pair;
+import com.google.gson.internal.Types;
+
 import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.HashMap;

gson/src/main/java/com/google/gson/VersionExclusionStrategy.java

@@ -18,6 +18,7 @@ package com.google.gson;
 
 import com.google.gson.annotations.Since;
 import com.google.gson.annotations.Until;
+import com.google.gson.internal.Preconditions;
 
 /**
  * This strategy will exclude any files and/or class that are passed the

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.google.gson;
+package com.google.gson.internal;
 
 /**
  * Defines generic cache interface.
@@ -22,7 +22,7 @@ package com.google.gson;
  * @author Inderjeet Singh
  * @author Joel Leitch
  */
-interface Cache<K, V> {
+public interface Cache<K, V> {
 
   /**
    * Adds the new value object into the cache for the given key.  If the key already

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

@@ -14,7 +14,8 @@
  * limitations under the License.
  */
 
-package com.google.gson;
+package com.google.gson.internal;
+
 
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -27,12 +28,12 @@ import java.util.Map;
  * @author Inderjeet Singh
  * @author Joel Leitch
  */
-final class LruCache<K, V> extends LinkedHashMap<K, V> implements Cache<K, V> {
+public final class LruCache<K, V> extends LinkedHashMap<K, V> implements Cache<K, V> {
   private static final long serialVersionUID = 1L;
 
   private final int maxCapacity;
 
-  LruCache(int maxCapacity) {
+  public LruCache(int maxCapacity) {
     super(maxCapacity, 0.7F, true);
     this.maxCapacity = maxCapacity;
   }

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.google.gson;
+package com.google.gson.internal;
 
 /**
  * A simple object that holds onto a pair of object references, first and second.
@@ -25,12 +25,11 @@ package com.google.gson;
  * @param <FIRST>
  * @param <SECOND>
  */
-final class Pair<FIRST, SECOND> {
+public final class Pair<FIRST, SECOND> {
+  public final FIRST first;
+  public final SECOND second;
 
-  final FIRST first;
-  final SECOND second;
-
-  Pair(FIRST first, SECOND second) {
+  public Pair(FIRST first, SECOND second) {
     this.first = first;
     this.second = second;
   }

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.google.gson;
+package com.google.gson.internal;
 
 /**
  * A simple utility class used to check method Preconditions.
@@ -29,7 +29,7 @@ package com.google.gson;
  * @author Inderjeet Singh
  * @author Joel Leitch
  */
-final class Preconditions {
+public final class Preconditions {
   public static <T> T checkNotNull(T obj) {
     if (obj == null) {
       throw new NullPointerException();

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

@@ -14,7 +14,8 @@
  * limitations under the License.
  */
 
-package com.google.gson;
+package com.google.gson.internal;
+
 
 import java.lang.reflect.Type;
 import java.util.Collections;
@@ -27,14 +28,14 @@ import java.util.Map;
  *
  * @author Kevin Bourrillion
  */
-final class Primitives {
+public final class Primitives {
   private Primitives() {}
 
   /** A map from primitive types to their corresponding wrapper types. */
-  public static final Map<Class<?>, Class<?>> PRIMITIVE_TO_WRAPPER_TYPE;
+  private static final Map<Class<?>, Class<?>> PRIMITIVE_TO_WRAPPER_TYPE;
 
   /** A map from wrapper types to their corresponding primitive types. */
-  public static final Map<Class<?>, Class<?>> WRAPPER_TO_PRIMITIVE_TYPE;
+  private static final Map<Class<?>, Class<?>> WRAPPER_TO_PRIMITIVE_TYPE;
 
   // Sad that we can't use a BiMap. :(
   

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.google.gson;
+package com.google.gson.internal;
 
 import java.io.Serializable;
 import java.lang.reflect.Array;
@@ -274,7 +274,7 @@ public final class Types {
    * Returns true if this type is an array.
    */
   @SuppressWarnings("unchecked")
-  static boolean isArray(Type type) {
+  public static boolean isArray(Type type) {
     return type instanceof GenericArrayType
         || (type instanceof Class && ((Class<?>) type).isArray());
   }
@@ -283,7 +283,7 @@ public final class Types {
    * Returns the component type of this array type.
    * @throws ClassCastException if this type is not an array.
    */
-  static Type getArrayComponentType(Type array) {
+  public static Type getArrayComponentType(Type array) {
     return array instanceof GenericArrayType
         ? ((GenericArrayType) array).getGenericComponentType()
         : ((Class<?>) array).getComponentType();
@@ -293,7 +293,7 @@ public final class Types {
    * Returns the element type of this collection type.
    * @throws IllegalArgumentException if this type is not a collection.
    */
-  static Type getCollectionElementType(Type context, Class<?> contextRawType) {
+  public static Type getCollectionElementType(Type context, Class<?> contextRawType) {
     Type collectionType = getSupertype(context, contextRawType, Collection.class);
     return ((ParameterizedType) collectionType).getActualTypeArguments()[0];
   }
@@ -302,7 +302,7 @@ public final class Types {
    * Returns a two element array containing this map's key and value types in
    * positions 0 and 1 respectively.
    */
-  static Type[] getMapKeyAndValueTypes(Type context, Class<?> contextRawType) {
+  public static Type[] getMapKeyAndValueTypes(Type context, Class<?> contextRawType) {
     /*
      * Work around a problem with the declaration of java.util.Properties. That
      * class should extend Hashtable<String, String>, but it's declared to
@@ -318,7 +318,7 @@ public final class Types {
   }
 
   @SuppressWarnings("unchecked")
-  static Type resolve(Type context, Class<?> contextRawType, Type toResolve) {
+  public static Type resolve(Type context, Class<?> contextRawType, Type toResolve) {
     // this implementation is made a little more complicated in an attempt to avoid object-creation
     while (true) {
       if (toResolve instanceof TypeVariable) {
@@ -390,7 +390,7 @@ public final class Types {
     }
   }
 
-  @SuppressWarnings({ "rawtypes", "unchecked" })
+  @SuppressWarnings("unchecked")
   static Type resolveTypeVariable(Type context, Class<?> contextRawType, TypeVariable unknown) {
     Class<?> declaredByRaw = declaringClassOf(unknown);
 

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.google.gson;
+package com.google.gson.internal;
 
 import java.io.ObjectInputStream;
 import java.io.ObjectStreamClass;
@@ -27,7 +27,7 @@ import java.lang.reflect.Method;
  * @author Joel Leitch
  * @author Jesse Wilson
  */
-abstract class UnsafeAllocator {
+public abstract class UnsafeAllocator {
   public abstract <T> T newInstance(Class<T> c) throws Exception;
 
   public static UnsafeAllocator create() {

gson/src/main/java/com/google/gson/reflect/TypeToken.java

@@ -16,7 +16,8 @@
 
 package com.google.gson.reflect;
 
-import com.google.gson.Types;
+import com.google.gson.internal.Types;
+
 import java.lang.reflect.GenericArrayType;
 import java.lang.reflect.Method;
 import java.lang.reflect.ParameterizedType;
@@ -35,11 +36,11 @@ import java.util.Map;
  * create an empty anonymous inner class:
  *
  * <p>
- * {@code TypeLiteral<List<String>> list = new TypeToken<List<String>>() {};}
+ * {@code TypeToken<List<String>> list = new TypeToken<List<String>>() {};}
  *
  * <p>This syntax cannot be used to create type literals that have wildcard
  * parameters, such as {@code Class<?>} or {@code List<? extends CharSequence>}.
- * Such type literals must be constructed programatically, either by {@link
+ * Such type tokens must be constructed programatically, either by {@link
  * Method#getGenericReturnType extracting types from members} or by using the
  * {@link Types} factory class.
  *

gson/src/test/java/com/google/gson/GenericArrayTypeTest.java

@@ -16,6 +16,7 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Types;
 import com.google.gson.reflect.TypeToken;
 
 import junit.framework.TestCase;

gson/src/test/java/com/google/gson/LruCacheTest.java

@@ -16,6 +16,9 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Cache;
+import com.google.gson.internal.LruCache;
+
 import junit.framework.TestCase;
 
 /**

gson/src/test/java/com/google/gson/MemoryRefStackTest.java

@@ -16,7 +16,6 @@
 
 package com.google.gson;
 
-import com.google.gson.MemoryRefStack;
 
 import junit.framework.TestCase;
 

gson/src/test/java/com/google/gson/ParameterizedTypeTest.java

@@ -16,6 +16,7 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Types;
 import com.google.gson.reflect.TypeToken;
 
 import junit.framework.TestCase;

gson/src/test/java/com/google/gson/ParamterizedTypeFixtures.java

@@ -16,6 +16,9 @@
 
 package com.google.gson;
 
+import com.google.gson.internal.Primitives;
+import com.google.gson.internal.Types;
+
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.ParameterizedType;

gson/src/test/java/com/google/gson/PrimitiveTypeAdapter.java

@@ -21,7 +21,7 @@ import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 
 import com.google.gson.JsonParseException;
-import com.google.gson.Primitives;
+import com.google.gson.internal.Primitives;
 
 /**
  * Handles type conversion from some object to some primitive (or primitive

gson/src/test/java/com/google/gson/functional/MapTest.java

@@ -19,8 +19,6 @@ package com.google.gson.functional;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.InstanceCreator;
-import com.google.gson.JsonElement;
-import com.google.gson.common.TestTypes.BagOfPrimitives;
 import com.google.gson.reflect.TypeToken;
 
 import junit.framework.TestCase;

gson/src/test/java/com/google/gson/functional/TypeHierarchyAdapterTest.java

@@ -133,10 +133,10 @@ public final class TypeHierarchyAdapterTest extends TestCase {
 
   public void testRegisterSubTypeFirstNotAllowed() {
     try {
-      Gson gson = new GsonBuilder()
-        .registerTypeHierarchyAdapter(Manager.class, new ManagerAdapter())
-        .registerTypeHierarchyAdapter(Employee.class, new EmployeeAdapter())
-        .create();
+      new GsonBuilder()
+          .registerTypeHierarchyAdapter(Manager.class, new ManagerAdapter())
+          .registerTypeHierarchyAdapter(Employee.class, new EmployeeAdapter())
+          .create();
       fail();
     } catch (IllegalArgumentException expected) {
     }