1 /**************************************************************** 2 * Licensed to the Apache Software Foundation (ASF) under one * 3 * or more contributor license agreements. See the NOTICE file * 4 * distributed with this work for additional information * 5 * regarding copyright ownership. The ASF licenses this file * 6 * to you under the Apache License, Version 2.0 (the * 7 * "License"); you may not use this file except in compliance * 8 * with the License. You may obtain a copy of the License at * 9 * * 10 * http://www.apache.org/licenses/LICENSE-2.0 * 11 * * 12 * Unless required by applicable law or agreed to in writing, * 13 * software distributed under the License is distributed on an * 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * 15 * KIND, either express or implied. See the License for the * 16 * specific language governing permissions and limitations * 17 * under the License. * 18 ****************************************************************/ 19 20 package org.apache.james.jdkim.canon; 21 22 import java.io.FilterOutputStream; 23 import java.io.IOException; 24 import java.io.OutputStream; 25 26 /** 27 * Pass data to the underlying system until a given amount of bytes is reached. 28 */ 29 public class LimitedOutputStream extends FilterOutputStream { 30 31 private int limit; 32 private int computedBytes; 33 34 /** 35 * @param out 36 * an output stream that will receive the "trucated" stream. 37 * @param limit 38 * a positive integer of the number of bytes to be passed to 39 * the underlying stream 40 */ 41 public LimitedOutputStream(OutputStream out, int limit) { 42 super(out); 43 this.limit = limit; 44 this.computedBytes = 0; 45 } 46 47 public void write(byte[] b, int off, int len) throws IOException { 48 if (len > limit - computedBytes) { 49 len = limit - computedBytes; 50 } 51 if (len > 0) { 52 out.write(b, off, len); 53 computedBytes += len; 54 } 55 } 56 57 public void write(int b) throws IOException { 58 if (computedBytes < limit) { 59 out.write(b); 60 computedBytes++; 61 } 62 } 63 64 /** 65 * @return the number of bytes passed to the underlying stream 66 */ 67 public int getComputedBytes() { 68 return computedBytes; 69 } 70 71 /** 72 * @return true if the limit has been reached and no data is being passed to 73 * the underlying stream. 74 */ 75 public boolean isLimited() { 76 return computedBytes >= limit; 77 } 78 }