1/*
2 * Copyright (C) 2012 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.reflect;
18
19import static com.google.common.base.Preconditions.checkArgument;
20
21import java.lang.reflect.ParameterizedType;
22import java.lang.reflect.Type;
23
24/**
25 * Captures the actual type of {@code T}.
26 *
27 * @author Ben Yu
28 */
29abstract class TypeCapture<T> {
30
31  /** Returns the captured type. */
32  final Type capture() {
33    Type superclass = getClass().getGenericSuperclass();
34    checkArgument(superclass instanceof ParameterizedType,
35        "%s isn't parameterized", superclass);
36    return ((ParameterizedType) superclass).getActualTypeArguments()[0];
37  }
38}
39