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.IOException; 22 import java.io.InputStream; 23 24 import org.apache.commons.io.IOUtils; 25 26 /** 27 * Always returns {@link IOUtils#EOF} to all attempts to read something from the stream. 28 * <p> 29 * Typically uses of this class include testing for corner cases in methods that accept input streams and acting as a 30 * sentinel value instead of a {@code null} input stream. 31 * </p> 32 * 33 * @since 1.4 34 */ 35 public class ClosedInputStream extends InputStream { 36 37 /** 38 * The singleton instance. 39 * 40 * @since 2.12.0 41 */ 42 public static final ClosedInputStream INSTANCE = new ClosedInputStream(); 43 44 /** 45 * The singleton instance. 46 * 47 * @deprecated Use {@link #INSTANCE}. 48 */ 49 @Deprecated 50 public static final ClosedInputStream CLOSED_INPUT_STREAM = INSTANCE; 51 52 /** 53 * Returns -1 to indicate that the stream is closed. 54 * 55 * @return always -1 56 */ 57 @Override 58 public int read() { 59 return EOF; 60 } 61 62 /** 63 * Returns -1 to indicate that the stream is closed. 64 * 65 * @param b ignored. 66 * @param off ignored. 67 * @param len ignored. 68 * @return always -1 69 */ 70 @Override 71 public int read(final byte[] b, final int off, final int len) throws IOException { 72 return EOF; 73 } 74 75 }