| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package flex.messaging.util; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * |
| */ |
| public class FileUtils |
| { |
| public static final String UTF_8 = "UTF-8"; |
| public static final String UTF_16 = "UTF-16"; |
| |
| /** |
| * Sets a mark in the InputStream for 3 bytes to check for a BOM. If the BOM |
| * stands for UTF-8 encoded content then the stream will not be reset, otherwise |
| * for UTF-16 with a BOM or any other encoding situation the stream is reset to the |
| * mark (as for UTF-16 the parser will handle the BOM). |
| * |
| * @param in InputStream containing BOM and must support mark(). |
| * @param default_encoding The default character set encoding. null or "" => system default |
| * @return The file character set encoding. |
| * @throws IOException |
| */ |
| public static final String consumeBOM(InputStream in, String default_encoding) throws IOException |
| { |
| in.mark(3); |
| |
| // Determine file encoding... |
| // ASCII - no header (use the supplied encoding) |
| // UTF8 - EF BB BF |
| // UTF16 - FF FE or FE FF (decoder chooses endian-ness) |
| if (in.read() == 0xef && in.read() == 0xbb && in.read() == 0xbf) |
| { |
| // UTF-8 reader does not consume BOM, so do not reset |
| if (System.getProperty("flex.platform.CLR") != null) |
| { |
| return "UTF8"; |
| } |
| else |
| { |
| return UTF_8; |
| } |
| } |
| else |
| { |
| in.reset(); |
| int b0 = in.read(); |
| int b1 = in.read(); |
| if (b0 == 0xff && b1 == 0xfe || b0 == 0xfe && b1 == 0xff) |
| { |
| in.reset(); |
| // UTF-16 reader will consume BOM |
| if (System.getProperty("flex.platform.CLR") != null) |
| { |
| return "UTF16"; |
| } |
| else |
| { |
| return UTF_16; |
| } |
| } |
| else |
| { |
| // no BOM found |
| in.reset(); |
| if (default_encoding != null && default_encoding.length() != 0) |
| { |
| return default_encoding; |
| } |
| else |
| { |
| return System.getProperty("file.encoding"); |
| } |
| } |
| } |
| } |
| |
| } |