001/* 002 * ==================================================================== 003 * Licensed to the Apache Software Foundation (ASF) under one 004 * or more contributor license agreements. See the NOTICE file 005 * distributed with this work for additional information 006 * regarding copyright ownership. The ASF licenses this file 007 * to you under the Apache License, Version 2.0 (the 008 * "License"); you may not use this file except in compliance 009 * with the License. You may obtain a copy of the License at 010 * 011 * http://www.apache.org/licenses/LICENSE-2.0 012 * 013 * Unless required by applicable law or agreed to in writing, 014 * software distributed under the License is distributed on an 015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 016 * KIND, either express or implied. See the License for the 017 * specific language governing permissions and limitations 018 * under the License. 019 * ==================================================================== 020 * 021 * This software consists of voluntary contributions made by many 022 * individuals on behalf of the Apache Software Foundation. For more 023 * information on the Apache Software Foundation, please see 024 * <http://www.apache.org/>. 025 * 026 */ 027package org.apache.http.client.entity; 028 029import java.io.IOException; 030import java.io.InputStream; 031 032/** 033 * Lazy init InputStream wrapper. 034 */ 035class LazyDecompressingInputStream extends InputStream { 036 037 private final InputStream wrappedStream; 038 private final InputStreamFactory inputStreamFactory; 039 040 private InputStream wrapperStream; 041 042 public LazyDecompressingInputStream( 043 final InputStream wrappedStream, 044 final InputStreamFactory inputStreamFactory) { 045 this.wrappedStream = wrappedStream; 046 this.inputStreamFactory = inputStreamFactory; 047 } 048 049 private void initWrapper() throws IOException { 050 if (wrapperStream == null) { 051 wrapperStream = inputStreamFactory.create(wrappedStream); 052 } 053 } 054 055 @Override 056 public int read() throws IOException { 057 initWrapper(); 058 return wrapperStream.read(); 059 } 060 061 @Override 062 public int read(final byte[] b) throws IOException { 063 initWrapper(); 064 return wrapperStream.read(b); 065 } 066 067 @Override 068 public int read(final byte[] b, final int off, final int len) throws IOException { 069 initWrapper(); 070 return wrapperStream.read(b, off, len); 071 } 072 073 @Override 074 public long skip(final long n) throws IOException { 075 initWrapper(); 076 return wrapperStream.skip(n); 077 } 078 079 @Override 080 public boolean markSupported() { 081 return false; 082 } 083 084 @Override 085 public int available() throws IOException { 086 initWrapper(); 087 return wrapperStream.available(); 088 } 089 090 @Override 091 public void close() throws IOException { 092 try { 093 if (wrapperStream != null) { 094 wrapperStream.close(); 095 } 096 } finally { 097 wrappedStream.close(); 098 } 099 } 100 101}