1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.io.input; 18 19 import static org.apache.commons.io.IOUtils.EOF; 20 21 import java.io.InputStream; 22 23 import org.apache.commons.io.IOUtils; 24 25 /** 26 * Always returns {@link IOUtils#EOF} to all attempts to read something from the stream. 27 * <p> 28 * Typically uses of this class include testing for corner cases in methods that accept input streams and acting as a 29 * sentinel value instead of a {@code null} input stream. 30 * </p> 31 * 32 * @since 1.4 33 */ 34 public class ClosedInputStream extends InputStream { 35 36 /** 37 * The singleton instance. 38 * 39 * @since 2.12.0 40 */ 41 public static final ClosedInputStream INSTANCE = new ClosedInputStream(); 42 43 /** 44 * The singleton instance. 45 * 46 * @deprecated Use {@link #INSTANCE}. 47 */ 48 @Deprecated 49 public static final ClosedInputStream CLOSED_INPUT_STREAM = INSTANCE; 50 51 /** 52 * Returns -1 to indicate that the stream is closed. 53 * 54 * @return always -1 55 */ 56 @Override read()57 public int read() { 58 return EOF; 59 } 60 61 } 62