All Downloads are FREE. Search and download functionalities are using the official Maven repository.

jodd.io.UnicodeInputStream Maven / Gradle / Ivy

Go to download

Easy Redis Java client and Real-Time Data Platform. Valkey compatible. Sync/Async/RxJava3/Reactive API. Client side caching. Over 50 Redis based Java objects and services: JCache API, Apache Tomcat, Hibernate, Spring, Set, Multimap, SortedSet, Map, List, Queue, Deque, Semaphore, Lock, AtomicLong, Map Reduce, Bloom filter, Scheduler, RPC

There is a newer version: 3.40.2
Show newest version
// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

package jodd.io;

import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;

/**
 * Unicode input stream for detecting UTF encodings and reading BOM characters.
 * Detects following BOMs:
 * 
    *
  • UTF-8
  • *
  • UTF-16BE
  • *
  • UTF-16LE
  • *
  • UTF-32BE
  • *
  • UTF-32LE
  • *
*/ public class UnicodeInputStream extends InputStream { public static final int MAX_BOM_SIZE = 4; private final PushbackInputStream internalInputStream; private boolean initialized; private int BOMSize = -1; private Charset encoding; private final Charset targetEncoding; /** * Creates new unicode stream. It works in two modes: detect mode and read mode. *

* Detect mode is active when target encoding is not specified. * In detect mode, it tries to detect encoding from BOM if exist. * If BOM doesn't exist, encoding is not detected. *

* Read mode is active when target encoding is set. Then this stream reads * optional BOM for given encoding. If BOM doesn't exist, nothing is skipped. */ public UnicodeInputStream(final InputStream in, final Charset targetEncoding) { internalInputStream = new PushbackInputStream(in, MAX_BOM_SIZE); this.targetEncoding = targetEncoding; } /** * Returns detected UTF encoding or {@code null} if no UTF encoding has been detected (i.e. no BOM). * If stream is not read yet, it will be {@link #init() initalized} first. */ public Charset getDetectedEncoding() { if (!initialized) { try { init(); } catch (final IOException ioex) { throw new IllegalStateException(ioex); } } return encoding; } public static final byte[] BOM_UTF32_BE = new byte[]{(byte) 0x00, (byte) 0x00, (byte) 0xFE, (byte) 0xFF}; public static final byte[] BOM_UTF32_LE = new byte[]{(byte) 0xFF, (byte) 0xFE, (byte) 0x00, (byte) 0x00}; public static final byte[] BOM_UTF8 = new byte[]{(byte) 0xEF, (byte) 0xBB, (byte) 0xBF}; public static final byte[] BOM_UTF16_BE = new byte[]{(byte) 0xFE, (byte) 0xFF}; public static final byte[] BOM_UTF16_LE = new byte[]{(byte) 0xFF, (byte) 0xFE}; /** * Detects and decodes encoding from BOM character. * Reads ahead four bytes and check for BOM marks. * Extra bytes are unread back to the stream, so only * BOM bytes are skipped. */ protected void init() throws IOException { if (initialized) { return; } if (targetEncoding == null) { // DETECT MODE final byte[] bom = new byte[MAX_BOM_SIZE]; final int n = internalInputStream.read(bom, 0, bom.length); final int unread; if ((bom[0] == BOM_UTF32_BE[0]) && (bom[1] == BOM_UTF32_BE[1]) && (bom[2] == BOM_UTF32_BE[2]) && (bom[3] == BOM_UTF32_BE[3])) { encoding = Charset.forName("UTF-32BE"); unread = n - 4; } else if ((bom[0] == BOM_UTF32_LE[0]) && (bom[1] == BOM_UTF32_LE[1]) && (bom[2] == BOM_UTF32_LE[2]) && (bom[3] == BOM_UTF32_LE[3])) { encoding = Charset.forName("UTF-32LE"); unread = n - 4; } else if ((bom[0] == BOM_UTF8[0]) && (bom[1] == BOM_UTF8[1]) && (bom[2] == BOM_UTF8[2])) { encoding = StandardCharsets.UTF_8; unread = n - 3; } else if ((bom[0] == BOM_UTF16_BE[0]) && (bom[1] == BOM_UTF16_BE[1])) { encoding = StandardCharsets.UTF_16BE; unread = n - 2; } else if ((bom[0] == BOM_UTF16_LE[0]) && (bom[1] == BOM_UTF16_LE[1])) { encoding = StandardCharsets.UTF_16LE; unread = n - 2; } else { // BOM not found, unread all bytes unread = n; } BOMSize = MAX_BOM_SIZE - unread; if (unread > 0) { internalInputStream.unread(bom, (n - unread), unread); } } else { // READ MODE byte[] bom = null; final String targetEncodingName = targetEncoding.name(); switch (targetEncodingName) { case "UTF-8": bom = BOM_UTF8; break; case "UTF-16LE": bom = BOM_UTF16_LE; break; case "UTF-16BE": case "UTF-16": bom = BOM_UTF16_BE; break; case "UTF-32LE": bom = BOM_UTF32_LE; break; case "UTF-32BE": case "UTF-32": bom = BOM_UTF32_BE; break; default: // no UTF encoding, no BOM break; } if (bom != null) { final byte[] fileBom = new byte[bom.length]; final int n = internalInputStream.read(fileBom, 0, bom.length); boolean bomDetected = true; for (int i = 0; i < n; i++) { if (fileBom[i] != bom[i]) { bomDetected = false; break; } } if (!bomDetected) { internalInputStream.unread(fileBom, 0, fileBom.length); } } } initialized = true; } /** * Closes input stream. If stream was not used, encoding * will be unavailable. */ @Override public void close() throws IOException { internalInputStream.close(); } /** * Reads byte from the stream. */ @Override public int read() throws IOException { init(); return internalInputStream.read(); } /** * Returns BOM size in bytes. * Returns -1 if BOM not found. */ public int getBOMSize() { return BOMSize; } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy