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.IOException; 022import java.io.InputStream; 023 024import org.apache.commons.io.IOUtils; 025 026/** 027 * Always returns {@link IOUtils#EOF} to all attempts to read something from the stream. 028 * <p> 029 * Typically uses of this class include testing for corner cases in methods that accept input streams and acting as a 030 * sentinel value instead of a {@code null} input stream. 031 * </p> 032 * 033 * @since 1.4 034 */ 035public class ClosedInputStream extends InputStream { 036 037 /** 038 * The singleton instance. 039 * 040 * @since 2.12.0 041 */ 042 public static final ClosedInputStream INSTANCE = new ClosedInputStream(); 043 044 /** 045 * The singleton instance. 046 * 047 * @deprecated Use {@link #INSTANCE}. 048 */ 049 @Deprecated 050 public static final ClosedInputStream CLOSED_INPUT_STREAM = INSTANCE; 051 052 /** 053 * Returns -1 to indicate that the stream is closed. 054 * 055 * @return always -1 056 */ 057 @Override 058 public int read() { 059 return EOF; 060 } 061 062 /** 063 * Returns -1 to indicate that the stream is closed. 064 * 065 * @param b ignored. 066 * @param off ignored. 067 * @param len ignored. 068 * @return always -1 069 */ 070 @Override 071 public int read(final byte[] b, final int off, final int len) throws IOException { 072 return EOF; 073 } 074 075}