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.FilterWriter; 20 import java.io.IOException; 21 import java.io.Writer; 22 23 import org.apache.commons.io.IOUtils; 24 25 /** 26 * Writer which breaks larger output blocks into chunks. 27 * Native code may need to copy the input array; if the write buffer 28 * is very large this can cause OOME. 29 * 30 * @since 2.5 31 */ 32 public class ChunkedWriter extends FilterWriter { 33 34 /** 35 * The default chunk size to use, i.e. {@value} bytes. 36 */ 37 private static final int DEFAULT_CHUNK_SIZE = IOUtils.DEFAULT_BUFFER_SIZE; 38 39 /** 40 * The maximum chunk size to us when writing data arrays 41 */ 42 private final int chunkSize; 43 44 /** 45 * Constructs a new writer that uses a chunk size of {@link #DEFAULT_CHUNK_SIZE} 46 * @param writer the writer to wrap 47 */ 48 public ChunkedWriter(final Writer writer) { 49 this(writer, DEFAULT_CHUNK_SIZE); 50 } 51 52 /** 53 * Constructs a new writer that uses the specified chunk size. 54 * 55 * @param writer the writer to wrap 56 * @param chunkSize the chunk size to use; must be a positive number. 57 * @throws IllegalArgumentException if the chunk size is <= 0 58 */ 59 public ChunkedWriter(final Writer writer, final int chunkSize) { 60 super(writer); 61 if (chunkSize <= 0) { 62 throw new IllegalArgumentException(); 63 } 64 this.chunkSize = chunkSize; 65 } 66 67 /** 68 * Writes the data buffer in chunks to the underlying writer. 69 * 70 * @param data The data 71 * @param srcOffset the offset 72 * @param length the number of bytes to write 73 * 74 * @throws IOException upon error 75 */ 76 @Override 77 public void write(final char[] data, final int srcOffset, final int length) throws IOException { 78 int bytes = length; 79 int dstOffset = srcOffset; 80 while (bytes > 0) { 81 final int chunk = Math.min(bytes, chunkSize); 82 out.write(data, dstOffset, chunk); 83 bytes -= chunk; 84 dstOffset += chunk; 85 } 86 } 87 88 }