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 java.io.InputStream; 20 21 /** 22 * Closed input stream. This stream returns -1 to all attempts to read 23 * something from the stream. 24 * <p> 25 * Typically uses of this class include testing for corner cases in methods 26 * that accept input streams and acting as a sentinel value instead of a 27 * <code>null</code> input stream. 28 * 29 * @version $Id: ClosedInputStream.java 601751 2007-12-06 14:55:45Z niallp $ 30 * @since Commons IO 1.4 31 */ 32 public class ClosedInputStream extends InputStream { 33 34 /** 35 * A singleton. 36 */ 37 public static final ClosedInputStream CLOSED_INPUT_STREAM = new ClosedInputStream(); 38 39 /** 40 * Returns -1 to indicate that the stream is closed. 41 * 42 * @return always -1 43 */ 44 public int read() { 45 return -1; 46 } 47 48 } 49
