001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.io.input; 018 019import static org.apache.commons.io.IOUtils.EOF; 020 021import java.io.InputStream; 022 023import org.apache.commons.io.IOUtils; 024 025/** 026 * Always returns {@link IOUtils#EOF} to all attempts to read something from the stream. 027 * <p> 028 * Typically uses of this class include testing for corner cases in methods that accept input streams and acting as a 029 * sentinel value instead of a {@code null} input stream. 030 * </p> 031 * 032 * @since 1.4 033 */ 034public class ClosedInputStream extends InputStream { 035 036 /** 037 * The singleton instance. 038 * 039 * @since 2.12.0 040 */ 041 public static final ClosedInputStream INSTANCE = new ClosedInputStream(); 042 043 /** 044 * The singleton instance. 045 * 046 * @deprecated Use {@link #INSTANCE}. 047 */ 048 @Deprecated 049 public static final ClosedInputStream CLOSED_INPUT_STREAM = INSTANCE; 050 051 /** 052 * Returns -1 to indicate that the stream is closed. 053 * 054 * @return always -1 055 */ 056 @Override 057 public int read() { 058 return EOF; 059 } 060 061}