Moved some methods from Either to TypeUtils

Author: spoenemann

org.eclipse.lsp4j.jsonrpc/src/main/java/org/eclipse/lsp4j/jsonrpc/json/adapters/EitherTypeAdapterFactory.java

@@ -9,8 +9,8 @@
 
 import java.io.IOException;
 import java.lang.reflect.Type;
-import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashSet;
 
 import org.eclipse.lsp4j.jsonrpc.messages.Either;
 import org.eclipse.lsp4j.jsonrpc.messages.Either3;
@@ -31,7 +31,7 @@ public class EitherTypeAdapterFactory implements TypeAdapterFactory {
 	@SuppressWarnings({ "rawtypes", "unchecked" })
 	@Override
 	public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
-		if (!Either.isEither(typeToken.getType())) {
+		if (!TypeUtils.isEither(typeToken.getType())) {
 			return null;
 		}
 		return new Adapter(gson, typeToken);
@@ -102,9 +102,9 @@ protected static class EitherTypeArgument<T> {
 		public EitherTypeArgument(Gson gson, Type type) {
 			this.token = (TypeToken<T>) TypeToken.get(type);
 			this.adapter = gson.getAdapter(this.token);
-			this.expectedTokens = new ArrayList<>();
-			for (Type disjoinType : Either.getAllDisjoinTypes(type)) {
-				Class<?> rawType = TypeToken.get(disjoinType).getRawType();
+			this.expectedTokens = new HashSet<>();
+			for (Type expectedType : TypeUtils.getExpectedTypes(type)) {
+				Class<?> rawType = TypeToken.get(expectedType).getRawType();
 				JsonToken expectedToken = getExpectedToken(rawType);
 				expectedTokens.add(expectedToken);
 			}

org.eclipse.lsp4j.jsonrpc/src/main/java/org/eclipse/lsp4j/jsonrpc/json/adapters/TypeUtils.java

@@ -11,18 +11,21 @@
 import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
 import java.lang.reflect.WildcardType;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
+import org.eclipse.lsp4j.jsonrpc.messages.Either;
+
 import com.google.gson.reflect.TypeToken;
 
 /**
  * Utilities for handling types in the JSON parser / serializer.
  */
-public class TypeUtils {
+public final class TypeUtils {
 
 	private TypeUtils() {}
 
@@ -175,5 +178,47 @@ private String toString(Type type) {
 		}
 
 	}
+	
+	/**
+	 * Return all possible types that can be expected when an element of the given type is parsed.
+	 * If the type satisfies {@link #isEither(Type)}, a list of the corresponding type arguments is returned,
+	 * otherwise a list containg the type itself is returned. Type parameters are <em>not</em> resolved
+	 * by this method (use {@link #getElementTypes(TypeToken, Class)} to get resolved parameters).
+	 */
+	public static Collection<Type> getExpectedTypes(Type type) {
+		Collection<Type> result = new ArrayList<>();
+		collectExpectedTypes(type, result);
+		return result;
+	}
+
+	private static void collectExpectedTypes(Type type, Collection<Type> types) {
+		if (isEither(type)) {
+			if (type instanceof ParameterizedType) {
+				for (Type typeArgument : ((ParameterizedType) type).getActualTypeArguments()) {
+					collectExpectedTypes(typeArgument, types);
+				}
+			}
+			if (type instanceof Class) {
+				for (Type typeParameter : ((Class<?>) type).getTypeParameters()) {
+					collectExpectedTypes(typeParameter, types);
+				}
+			}
+		} else {
+			types.add(type);
+		}
+	}
+
+	/**
+	 * Test whether the given type is Either.
+	 */
+	public static boolean isEither(Type type) {
+		if (type instanceof ParameterizedType) {
+			return isEither(((ParameterizedType) type).getRawType());
+		}
+		if (type instanceof Class) {
+			return Either.class.isAssignableFrom((Class<?>) type);
+		}
+		return false;
+	}
 
 }

org.eclipse.lsp4j.jsonrpc/src/main/java/org/eclipse/lsp4j/jsonrpc/messages/Either.java

@@ -120,11 +120,15 @@ public static Type getRightDisjointType(Type type) {
 
 	/**
 	 * Return all disjoint types.
+	 * 
+	 * @deprecated Use {@link org.eclipse.lsp4j.jsonrpc.json.adapters.TypeUtils#getExpectedTypes(Type)} instead
 	 */
+	@Deprecated
 	public static Collection<Type> getAllDisjoinTypes(Type type) {
 		return collectDisjoinTypes(type, new ArrayList<>());
 	}
 
+	@Deprecated
 	protected static Collection<Type> collectDisjoinTypes(Type type, Collection<Type> types) {
 		if (isEither(type)) {
 			if (type instanceof ParameterizedType) {
@@ -138,13 +142,15 @@ protected static Collection<Type> collectDisjoinTypes(Type type, Collection<Type
 		return types;
 	}
 
+	@Deprecated
 	protected static Collection<Type> collectDisjoinTypes(ParameterizedType type, Collection<Type> types) {
 		for (Type typeArgument : type.getActualTypeArguments()) {
 			collectDisjoinTypes(typeArgument, types);
 		}
 		return types;
 	}
 
+	@Deprecated
 	protected static Collection<Type> collectDisjoinTypes(Class<?> type, Collection<Type> types) {
 		for (Type typeParameter : type.getTypeParameters()) {
 			collectDisjoinTypes(typeParameter, types);
@@ -154,7 +160,10 @@ protected static Collection<Type> collectDisjoinTypes(Class<?> type, Collection<
 
 	/**
 	 * Test whether the given type is Either.
+	 * 
+	 * @deprecated Use {@link org.eclipse.lsp4j.jsonrpc.json.adapters.TypeUtils#isEither(Type)} instead
 	 */
+	@Deprecated
 	public static boolean isEither(Type type) {
 		if (type instanceof ParameterizedType) {
 			return isEither((ParameterizedType) type);
@@ -167,14 +176,20 @@ public static boolean isEither(Type type) {
 
 	/**
 	 * Test whether the given type is Either.
+	 * 
+	 * @deprecated Use {@link org.eclipse.lsp4j.jsonrpc.json.adapters.TypeUtils#isEither(Type)} instead
 	 */
+	@Deprecated
 	public static boolean isEither(ParameterizedType type) {
 		return isEither(type.getRawType());
 	}
 
 	/**
 	 * Test whether the given class is Either.
+	 * 
+	 * @deprecated Use {@link org.eclipse.lsp4j.jsonrpc.json.adapters.TypeUtils#isEither(Type)} instead
 	 */
+	@Deprecated
 	public static boolean isEither(Class<?> cls) {
 		return Either.class.isAssignableFrom(cls);
 	}