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 */ 017package org.apache.commons.fileupload.util; 018 019import java.io.ByteArrayOutputStream; 020import java.io.IOException; 021import java.io.InputStream; 022import java.io.OutputStream; 023 024import org.apache.commons.fileupload.InvalidFileNameException; 025import org.apache.commons.io.IOUtils; 026import org.apache.commons.io.output.NullOutputStream; 027 028/** 029 * Utility class for working with streams. 030 */ 031public final class Streams { 032 033 /** 034 * Default buffer size for use in 035 * {@link #copy(InputStream, OutputStream, boolean)}. 036 */ 037 public static final int DEFAULT_BUFFER_SIZE = 8192; 038 039 /** 040 * This convenience method allows to read a 041 * {@link org.apache.commons.fileupload.FileItemStream}'s 042 * content into a string. The platform's default character encoding 043 * is used for converting bytes into characters. 044 * 045 * @param inputStream The input stream to read. 046 * @see #asString(InputStream, String) 047 * @return The streams contents, as a string. 048 * @throws IOException An I/O error occurred. 049 */ 050 public static String asString(final InputStream inputStream) throws IOException { 051 final ByteArrayOutputStream baos = new ByteArrayOutputStream(); 052 copy(inputStream, baos, true); 053 return baos.toString(); 054 } 055 056 /** 057 * This convenience method allows to read a 058 * {@link org.apache.commons.fileupload.FileItemStream}'s 059 * content into a string, using the given character encoding. 060 * 061 * @param inputStream The input stream to read. 062 * @param encoding The character encoding, typically "UTF-8". 063 * @see #asString(InputStream) 064 * @return The streams contents, as a string. 065 * @throws IOException An I/O error occurred. 066 */ 067 public static String asString(final InputStream inputStream, final String encoding) throws IOException { 068 final ByteArrayOutputStream baos = new ByteArrayOutputStream(); 069 copy(inputStream, baos, true); 070 return baos.toString(encoding); 071 } 072 073 /** 074 * Checks, whether the given file name is valid in the sense, 075 * that it doesn't contain any NUL characters. If the file name 076 * is valid, it will be returned without any modifications. Otherwise, 077 * an {@link InvalidFileNameException} is raised. 078 * 079 * @param fileName The file name to check 080 * @return Unmodified file name, if valid. 081 * @throws InvalidFileNameException The file name was found to be invalid. 082 */ 083 public static String checkFileName(final String fileName) { 084 if (fileName != null && fileName.indexOf('\u0000') != -1) { 085 // fileName.replace("\u0000", "\\0") 086 final StringBuilder sb = new StringBuilder(); 087 for (int i = 0; i < fileName.length(); i++) { 088 final char c = fileName.charAt(i); 089 switch (c) { 090 case 0: 091 sb.append("\\0"); 092 break; 093 default: 094 sb.append(c); 095 break; 096 } 097 } 098 throw new InvalidFileNameException(fileName, 099 "Invalid file name: " + sb); 100 } 101 return fileName; 102 } 103 104 /** 105 * Copies the contents of the given {@link InputStream} 106 * to the given {@link OutputStream}. Shortcut for 107 * <pre> 108 * copy(pInputStream, outputStream, new byte[8192]); 109 * </pre> 110 * 111 * @param inputStream The input stream, which is being read. 112 * It is guaranteed, that {@link InputStream#close()} is called 113 * on the stream. 114 * @param outputStream The output stream, to which data should 115 * be written. May be null, in which case the input streams 116 * contents are simply discarded. 117 * @param closeOutputStream True guarantees, that {@link OutputStream#close()} 118 * is called on the stream. False indicates, that only 119 * {@link OutputStream#flush()} should be called finally. 120 * 121 * @return Number of bytes, which have been copied. 122 * @throws IOException An I/O error occurred. 123 */ 124 public static long copy(final InputStream inputStream, final OutputStream outputStream, 125 final boolean closeOutputStream) 126 throws IOException { 127 return copy(inputStream, outputStream, closeOutputStream, new byte[DEFAULT_BUFFER_SIZE]); 128 } 129 130 /** 131 * Copies the contents of the given {@link InputStream} 132 * to the given {@link OutputStream}. 133 * 134 * @param inputStream The input stream, which is being read. 135 * It is guaranteed, that {@link InputStream#close()} is called 136 * on the stream. 137 * @param outputStream The output stream, to which data should 138 * be written. May be null, in which case the input streams 139 * contents are simply discarded. 140 * @param closeOutputStream True guarantees, that {@link OutputStream#close()} 141 * is called on the stream. False indicates, that only 142 * {@link OutputStream#flush()} should be called finally. 143 * @param buffer Temporary buffer, which is to be used for 144 * copying data. 145 * @return Number of bytes, which have been copied. 146 * @throws IOException An I/O error occurred. 147 */ 148 public static long copy(final InputStream inputStream, final OutputStream outputStream, final boolean closeOutputStream, final byte[] buffer) 149 throws IOException { 150 try { 151 return IOUtils.copyLarge(inputStream, outputStream != null ? outputStream : NullOutputStream.INSTANCE, buffer); 152 } finally { 153 IOUtils.closeQuietly(inputStream); 154 if (closeOutputStream) { 155 IOUtils.closeQuietly(outputStream); 156 } 157 } 158 } 159 160 /** 161 * Private constructor, to prevent instantiation. 162 * This class has only static methods. 163 */ 164 private Streams() { 165 // Does nothing 166 } 167 168}