001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.fileupload.util; 018 019 import java.io.ByteArrayOutputStream; 020 import java.io.IOException; 021 import java.io.InputStream; 022 import java.io.OutputStream; 023 024 025 /** Utility class for working with streams. 026 */ 027 public final class Streams { 028 /** 029 * Private constructor, to prevent instantiation. 030 * This class has only static methods. 031 */ 032 private Streams() { 033 // Does nothing 034 } 035 036 /** 037 * Default buffer size for use in 038 * {@link #copy(InputStream, OutputStream, boolean)}. 039 */ 040 private static final int DEFAULT_BUFFER_SIZE = 8192; 041 042 /** 043 * Copies the contents of the given {@link InputStream} 044 * to the given {@link OutputStream}. Shortcut for 045 * <pre> 046 * copy(pInputStream, pOutputStream, new byte[8192]); 047 * </pre> 048 * @param pInputStream The input stream, which is being read. 049 * It is guaranteed, that {@link InputStream#close()} is called 050 * on the stream. 051 * @param pOutputStream The output stream, to which data should 052 * be written. May be null, in which case the input streams 053 * contents are simply discarded. 054 * @param pClose True guarantees, that {@link OutputStream#close()} 055 * is called on the stream. False indicates, that only 056 * {@link OutputStream#flush()} should be called finally. 057 * 058 * @return Number of bytes, which have been copied. 059 * @throws IOException An I/O error occurred. 060 */ 061 public static long copy(InputStream pInputStream, 062 OutputStream pOutputStream, boolean pClose) 063 throws IOException { 064 return copy(pInputStream, pOutputStream, pClose, 065 new byte[DEFAULT_BUFFER_SIZE]); 066 } 067 068 /** 069 * Copies the contents of the given {@link InputStream} 070 * to the given {@link OutputStream}. 071 * @param pIn The input stream, which is being read. 072 * It is guaranteed, that {@link InputStream#close()} is called 073 * on the stream. 074 * @param pOut The output stream, to which data should 075 * be written. May be null, in which case the input streams 076 * contents are simply discarded. 077 * @param pClose True guarantees, that {@link OutputStream#close()} 078 * is called on the stream. False indicates, that only 079 * {@link OutputStream#flush()} should be called finally. 080 * @param pBuffer Temporary buffer, which is to be used for 081 * copying data. 082 * @return Number of bytes, which have been copied. 083 * @throws IOException An I/O error occurred. 084 */ 085 public static long copy(InputStream pIn, 086 OutputStream pOut, boolean pClose, 087 byte[] pBuffer) 088 throws IOException { 089 OutputStream out = pOut; 090 InputStream in = pIn; 091 try { 092 long total = 0; 093 for (;;) { 094 int res = in.read(pBuffer); 095 if (res == -1) { 096 break; 097 } 098 if (res > 0) { 099 total += res; 100 if (out != null) { 101 out.write(pBuffer, 0, res); 102 } 103 } 104 } 105 if (out != null) { 106 if (pClose) { 107 out.close(); 108 } else { 109 out.flush(); 110 } 111 out = null; 112 } 113 in.close(); 114 in = null; 115 return total; 116 } finally { 117 if (in != null) { 118 try { 119 in.close(); 120 } catch (Throwable t) { 121 /* Ignore me */ 122 } 123 } 124 if (pClose && out != null) { 125 try { 126 out.close(); 127 } catch (Throwable t) { 128 /* Ignore me */ 129 } 130 } 131 } 132 } 133 134 /** 135 * This convenience method allows to read a 136 * {@link org.apache.commons.fileupload.FileItemStream}'s 137 * content into a string. The platform's default character encoding 138 * is used for converting bytes into characters. 139 * @param pStream The input stream to read. 140 * @see #asString(InputStream, String) 141 * @return The streams contents, as a string. 142 * @throws IOException An I/O error occurred. 143 */ 144 public static String asString(InputStream pStream) throws IOException { 145 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 146 copy(pStream, baos, true); 147 return baos.toString(); 148 } 149 150 /** 151 * This convenience method allows to read a 152 * {@link org.apache.commons.fileupload.FileItemStream}'s 153 * content into a string, using the given character encoding. 154 * @param pStream The input stream to read. 155 * @param pEncoding The character encoding, typically "UTF-8". 156 * @see #asString(InputStream) 157 * @return The streams contents, as a string. 158 * @throws IOException An I/O error occurred. 159 */ 160 public static String asString(InputStream pStream, String pEncoding) 161 throws IOException { 162 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 163 copy(pStream, baos, true); 164 return baos.toString(pEncoding); 165 } 166 }