| /* |
| * 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 org.apache.tomcat.util.buf; |
| |
| import java.io.IOException; |
| import java.io.UnsupportedEncodingException; |
| import java.nio.ByteBuffer; |
| import java.nio.CharBuffer; |
| import java.nio.charset.Charset; |
| import java.nio.charset.CharsetDecoder; |
| import java.nio.charset.CoderResult; |
| import java.nio.charset.CodingErrorAction; |
| import java.nio.charset.StandardCharsets; |
| import java.util.HashMap; |
| import java.util.Locale; |
| import java.util.Map; |
| |
| import org.apache.tomcat.util.res.StringManager; |
| |
| /** |
| * NIO based character decoder. |
| */ |
| public class B2CConverter { |
| |
| private static final StringManager sm = |
| StringManager.getManager(Constants.Package); |
| |
| private static final Map<String, Charset> encodingToCharsetCache = |
| new HashMap<>(); |
| |
| // Protected so unit tests can use it |
| protected static final int LEFTOVER_SIZE = 9; |
| |
| static { |
| for (Charset charset: Charset.availableCharsets().values()) { |
| encodingToCharsetCache.put( |
| charset.name().toLowerCase(Locale.ENGLISH), charset); |
| for (String alias : charset.aliases()) { |
| encodingToCharsetCache.put( |
| alias.toLowerCase(Locale.ENGLISH), charset); |
| } |
| } |
| } |
| |
| public static Charset getCharset(String enc) |
| throws UnsupportedEncodingException { |
| |
| // Encoding names should all be ASCII |
| String lowerCaseEnc = enc.toLowerCase(Locale.ENGLISH); |
| |
| return getCharsetLower(lowerCaseEnc); |
| } |
| |
| /** |
| * Only to be used when it is known that the encoding name is in lower case. |
| */ |
| public static Charset getCharsetLower(String lowerCaseEnc) |
| throws UnsupportedEncodingException { |
| |
| Charset charset = encodingToCharsetCache.get(lowerCaseEnc); |
| |
| if (charset == null) { |
| // Pre-population of the cache means this must be invalid |
| throw new UnsupportedEncodingException( |
| sm.getString("b2cConverter.unknownEncoding", lowerCaseEnc)); |
| } |
| return charset; |
| } |
| |
| private final CharsetDecoder decoder; |
| private ByteBuffer bb = null; |
| private CharBuffer cb = null; |
| |
| /** |
| * Leftover buffer used for incomplete characters. |
| */ |
| private final ByteBuffer leftovers; |
| |
| public B2CConverter(String encoding) throws IOException { |
| this(encoding, false); |
| } |
| |
| public B2CConverter(String encoding, boolean replaceOnError) |
| throws IOException { |
| byte[] left = new byte[LEFTOVER_SIZE]; |
| leftovers = ByteBuffer.wrap(left); |
| CodingErrorAction action; |
| if (replaceOnError) { |
| action = CodingErrorAction.REPLACE; |
| } else { |
| action = CodingErrorAction.REPORT; |
| } |
| Charset charset = getCharset(encoding); |
| // Special case. Use the Apache Harmony based UTF-8 decoder because it |
| // - a) rejects invalid sequences that the JVM decoder does not |
| // - b) fails faster for some invalid sequences |
| if (charset.equals(StandardCharsets.UTF_8)) { |
| decoder = new Utf8Decoder(); |
| } else { |
| decoder = charset.newDecoder(); |
| } |
| decoder.onMalformedInput(action); |
| decoder.onUnmappableCharacter(action); |
| } |
| |
| /** |
| * Reset the decoder state. |
| */ |
| public void recycle() { |
| decoder.reset(); |
| leftovers.position(0); |
| } |
| |
| /** |
| * Convert the given bytes to characters. |
| * |
| * @param bc byte input |
| * @param cc char output |
| * @param endOfInput Is this all of the available data |
| */ |
| public void convert(ByteChunk bc, CharChunk cc, boolean endOfInput) |
| throws IOException { |
| if ((bb == null) || (bb.array() != bc.getBuffer())) { |
| // Create a new byte buffer if anything changed |
| bb = ByteBuffer.wrap(bc.getBuffer(), bc.getStart(), bc.getLength()); |
| } else { |
| // Initialize the byte buffer |
| bb.limit(bc.getEnd()); |
| bb.position(bc.getStart()); |
| } |
| if ((cb == null) || (cb.array() != cc.getBuffer())) { |
| // Create a new char buffer if anything changed |
| cb = CharBuffer.wrap(cc.getBuffer(), cc.getEnd(), |
| cc.getBuffer().length - cc.getEnd()); |
| } else { |
| // Initialize the char buffer |
| cb.limit(cc.getBuffer().length); |
| cb.position(cc.getEnd()); |
| } |
| CoderResult result = null; |
| // Parse leftover if any are present |
| if (leftovers.position() > 0) { |
| int pos = cb.position(); |
| // Loop until one char is decoded or there is a decoder error |
| do { |
| leftovers.put(bc.substractB()); |
| leftovers.flip(); |
| result = decoder.decode(leftovers, cb, endOfInput); |
| leftovers.position(leftovers.limit()); |
| leftovers.limit(leftovers.array().length); |
| } while (result.isUnderflow() && (cb.position() == pos)); |
| if (result.isError() || result.isMalformed()) { |
| result.throwException(); |
| } |
| bb.position(bc.getStart()); |
| leftovers.position(0); |
| } |
| // Do the decoding and get the results into the byte chunk and the char |
| // chunk |
| result = decoder.decode(bb, cb, endOfInput); |
| if (result.isError() || result.isMalformed()) { |
| result.throwException(); |
| } else if (result.isOverflow()) { |
| // Propagate current positions to the byte chunk and char chunk, if |
| // this continues the char buffer will get resized |
| bc.setOffset(bb.position()); |
| cc.setEnd(cb.position()); |
| } else if (result.isUnderflow()) { |
| // Propagate current positions to the byte chunk and char chunk |
| bc.setOffset(bb.position()); |
| cc.setEnd(cb.position()); |
| // Put leftovers in the leftovers byte buffer |
| if (bc.getLength() > 0) { |
| leftovers.limit(leftovers.array().length); |
| leftovers.position(bc.getLength()); |
| bc.substract(leftovers.array(), 0, bc.getLength()); |
| } |
| } |
| } |
| } |