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.output; 18 19 import java.io.IOException; 20 import java.io.OutputStream; 21 22 /** 23 * A decorating output stream that counts the number of bytes that have passed 24 * through the stream so far. 25 * <p> 26 * A typical use case would be during debugging, to ensure that data is being 27 * written as expected. 28 * 29 * @version $Id: CountingOutputStream.java 471628 2006-11-06 04:06:45Z bayard $ 30 */ 31 public class CountingOutputStream extends ProxyOutputStream { 32 33 /** The count of bytes that have passed. */ 34 private long count; 35 36 /** 37 * Constructs a new CountingOutputStream. 38 * 39 * @param out the OutputStream to write to 40 */ 41 public CountingOutputStream( OutputStream out ) { 42 super(out); 43 } 44 45 //----------------------------------------------------------------------- 46 /** 47 * Writes the contents of the specified byte array to this output stream 48 * keeping count of the number of bytes written. 49 * 50 * @param b the bytes to write, not null 51 * @throws IOException if an I/O error occurs 52 * @see java.io.OutputStream#write(byte[]) 53 */ 54 public void write(byte[] b) throws IOException { 55 count += b.length; 56 super.write(b); 57 } 58 59 /** 60 * Writes a portion of the specified byte array to this output stream 61 * keeping count of the number of bytes written. 62 * 63 * @param b the bytes to write, not null 64 * @param off the start offset in the buffer 65 * @param len the maximum number of bytes to write 66 * @throws IOException if an I/O error occurs 67 * @see java.io.OutputStream#write(byte[], int, int) 68 */ 69 public void write(byte[] b, int off, int len) throws IOException { 70 count += len; 71 super.write(b, off, len); 72 } 73 74 /** 75 * Writes a single byte to the output stream adding to the count of the 76 * number of bytes written. 77 * 78 * @param b the byte to write 79 * @throws IOException if an I/O error occurs 80 * @see java.io.OutputStream#write(int) 81 */ 82 public void write(int b) throws IOException { 83 count++; 84 super.write(b); 85 } 86 87 //----------------------------------------------------------------------- 88 /** 89 * The number of bytes that have passed through this stream. 90 * <p> 91 * NOTE: From v1.3 this method throws an ArithmeticException if the 92 * count is greater than can be expressed by an <code>int</code>. 93 * See {@link #getByteCount()} for a method using a <code>long</code>. 94 * 95 * @return the number of bytes accumulated 96 * @throws ArithmeticException if the byte count is too large 97 */ 98 public synchronized int getCount() { 99 long result = getByteCount(); 100 if (result > Integer.MAX_VALUE) { 101 throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int"); 102 } 103 return (int) result; 104 } 105 106 /** 107 * Set the byte count back to 0. 108 * <p> 109 * NOTE: From v1.3 this method throws an ArithmeticException if the 110 * count is greater than can be expressed by an <code>int</code>. 111 * See {@link #resetByteCount()} for a method using a <code>long</code>. 112 * 113 * @return the count previous to resetting 114 * @throws ArithmeticException if the byte count is too large 115 */ 116 public synchronized int resetCount() { 117 long result = resetByteCount(); 118 if (result > Integer.MAX_VALUE) { 119 throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int"); 120 } 121 return (int) result; 122 } 123 124 /** 125 * The number of bytes that have passed through this stream. 126 * <p> 127 * NOTE: This method is an alternative for <code>getCount()</code>. 128 * It was added because that method returns an integer which will 129 * result in incorrect count for files over 2GB. 130 * 131 * @return the number of bytes accumulated 132 * @since Commons IO 1.3 133 */ 134 public synchronized long getByteCount() { 135 return this.count; 136 } 137 138 /** 139 * Set the byte count back to 0. 140 * <p> 141 * NOTE: This method is an alternative for <code>resetCount()</code>. 142 * It was added because that method returns an integer which will 143 * result in incorrect count for files over 2GB. 144 * 145 * @return the count previous to resetting 146 * @since Commons IO 1.3 147 */ 148 public synchronized long resetByteCount() { 149 long tmp = this.count; 150 this.count = 0; 151 return tmp; 152 } 153 154 } 155
