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 "License"); 7 * you may not use this file except in compliance with the License. 8 * 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, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 /* 19 * $Id: StringBufferPool.java 468655 2006-10-28 07:12:06Z minchau $ 20 */ 21 package org.apache.xml.utils; 22 23 /** 24 * This class pools string buffers, since they are reused so often. 25 * String buffers are good candidates for pooling, because of 26 * their supporting character arrays. 27 * @xsl.usage internal 28 */ 29 public class StringBufferPool 30 { 31 32 /** The global pool of string buffers. */ 33 private static ObjectPool m_stringBufPool = 34 new ObjectPool(org.apache.xml.utils.FastStringBuffer.class); 35 36 /** 37 * Get the first free instance of a string buffer, or create one 38 * if there are no free instances. 39 * 40 * @return A string buffer ready for use. 41 */ get()42 public synchronized static FastStringBuffer get() 43 { 44 return (FastStringBuffer) m_stringBufPool.getInstance(); 45 } 46 47 /** 48 * Return a string buffer back to the pool. 49 * 50 * @param sb Must be a non-null reference to a string buffer. 51 */ free(FastStringBuffer sb)52 public synchronized static void free(FastStringBuffer sb) 53 { 54 // Since this isn't synchronized, setLength must be 55 // done before the instance is freed. 56 // Fix attributed to Peter Speck <speck@ruc.dk>. 57 sb.setLength(0); 58 m_stringBufPool.freeInstance(sb); 59 } 60 } 61