| /* |
| * Copyright (c) 2009, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.xml.internal.dtdparser; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.CharConversionException; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.io.PushbackInputStream; |
| import java.io.Reader; |
| import java.util.Hashtable; |
| |
| |
| // NOTE: Add I18N support to this class when JDK gets the ability to |
| // defer selection of locale for exception messages ... use the same |
| // technique for both. |
| |
| |
| /** |
| * This handles several XML-related tasks that normal java.io Readers |
| * don't support, inluding use of IETF standard encoding names and |
| * automatic detection of most XML encodings. The former is needed |
| * for interoperability; the latter is needed to conform with the XML |
| * spec. This class also optimizes reading some common encodings by |
| * providing low-overhead unsynchronized Reader support. |
| * <p/> |
| * <P> Note that the autodetection facility should be used only on |
| * data streams which have an unknown character encoding. For example, |
| * it should never be used on MIME text/xml entities. |
| * <p/> |
| * <P> Note that XML processors are only required to support UTF-8 and |
| * UTF-16 character encodings. Autodetection permits the underlying Java |
| * implementation to provide support for many other encodings, such as |
| * US-ASCII, ISO-8859-5, Shift_JIS, EUC-JP, and ISO-2022-JP. |
| * |
| * @author David Brownell |
| * @author Janet Koenig |
| * @version 1.3 00/02/24 |
| */ |
| // package private |
| final class XmlReader extends Reader { |
| private static final int MAXPUSHBACK = 512; |
| |
| private Reader in; |
| private String assignedEncoding; |
| private boolean closed; |
| |
| // |
| // This class always delegates I/O to a reader, which gets |
| // its data from the very beginning of the XML text. It needs |
| // to use a pushback stream since (a) autodetection can read |
| // partial UTF-8 characters which need to be fully processed, |
| // (b) the "Unicode" readers swallow characters that they think |
| // are byte order marks, so tests fail if they don't see the |
| // real byte order mark. |
| // |
| // It's got do this efficiently: character I/O is solidly on the |
| // critical path. (So keep buffer length over 2 Kbytes to avoid |
| // excess buffering. Many URL handlers stuff a BufferedInputStream |
| // between here and the real data source, and larger buffers keep |
| // that from slowing you down.) |
| // |
| |
| /** |
| * Constructs the reader from an input stream, autodetecting |
| * the encoding to use according to the heuristic specified |
| * in the XML 1.0 recommendation. |
| * |
| * @param in the input stream from which the reader is constructed |
| * @throws IOException on error, such as unrecognized encoding |
| */ |
| public static Reader createReader(InputStream in) throws IOException { |
| return new XmlReader(in); |
| } |
| |
| /** |
| * Creates a reader supporting the given encoding, mapping |
| * from standard encoding names to ones that understood by |
| * Java where necessary. |
| * |
| * @param in the input stream from which the reader is constructed |
| * @param encoding the IETF standard name of the encoding to use; |
| * if null, autodetection is used. |
| * @throws IOException on error, including unrecognized encoding |
| */ |
| public static Reader createReader(InputStream in, String encoding) |
| throws IOException { |
| if (encoding == null) |
| return new XmlReader(in); |
| if ("UTF-8".equalsIgnoreCase(encoding) |
| || "UTF8".equalsIgnoreCase(encoding)) |
| return new Utf8Reader(in); |
| if ("US-ASCII".equalsIgnoreCase(encoding) |
| || "ASCII".equalsIgnoreCase(encoding)) |
| return new AsciiReader(in); |
| if ("ISO-8859-1".equalsIgnoreCase(encoding) |
| // plus numerous aliases ... |
| ) |
| return new Iso8859_1Reader(in); |
| |
| // |
| // What we really want is an administerable resource mapping |
| // encoding names/aliases to classnames. For example a property |
| // file resource, "readers/mapping.props", holding and a set |
| // of readers in that (sub)package... defaulting to this call |
| // only if no better choice is available. |
| // |
| return new InputStreamReader(in, std2java(encoding)); |
| } |
| |
| // |
| // JDK doesn't know all of the standard encoding names, and |
| // in particular none of the EBCDIC ones IANA defines (and |
| // which IBM encourages). |
| // |
| static private final Hashtable charsets = new Hashtable(31); |
| |
| static { |
| charsets.put("UTF-16", "Unicode"); |
| charsets.put("ISO-10646-UCS-2", "Unicode"); |
| |
| // NOTE: no support for ISO-10646-UCS-4 yet. |
| |
| charsets.put("EBCDIC-CP-US", "cp037"); |
| charsets.put("EBCDIC-CP-CA", "cp037"); |
| charsets.put("EBCDIC-CP-NL", "cp037"); |
| charsets.put("EBCDIC-CP-WT", "cp037"); |
| |
| charsets.put("EBCDIC-CP-DK", "cp277"); |
| charsets.put("EBCDIC-CP-NO", "cp277"); |
| charsets.put("EBCDIC-CP-FI", "cp278"); |
| charsets.put("EBCDIC-CP-SE", "cp278"); |
| |
| charsets.put("EBCDIC-CP-IT", "cp280"); |
| charsets.put("EBCDIC-CP-ES", "cp284"); |
| charsets.put("EBCDIC-CP-GB", "cp285"); |
| charsets.put("EBCDIC-CP-FR", "cp297"); |
| |
| charsets.put("EBCDIC-CP-AR1", "cp420"); |
| charsets.put("EBCDIC-CP-HE", "cp424"); |
| charsets.put("EBCDIC-CP-BE", "cp500"); |
| charsets.put("EBCDIC-CP-CH", "cp500"); |
| |
| charsets.put("EBCDIC-CP-ROECE", "cp870"); |
| charsets.put("EBCDIC-CP-YU", "cp870"); |
| charsets.put("EBCDIC-CP-IS", "cp871"); |
| charsets.put("EBCDIC-CP-AR2", "cp918"); |
| |
| // IANA also defines two that JDK 1.2 doesn't handle: |
| // EBCDIC-CP-GR --> CP423 |
| // EBCDIC-CP-TR --> CP905 |
| } |
| |
| // returns an encoding name supported by JDK >= 1.1.6 |
| // for some cases required by the XML spec |
| private static String std2java(String encoding) { |
| String temp = encoding.toUpperCase(); |
| temp = (String) charsets.get(temp); |
| return temp != null ? temp : encoding; |
| } |
| |
| /** |
| * Returns the standard name of the encoding in use |
| */ |
| public String getEncoding() { |
| return assignedEncoding; |
| } |
| |
| private XmlReader(InputStream stream) throws IOException { |
| super(stream); |
| |
| PushbackInputStream pb; |
| byte buf []; |
| int len; |
| |
| if (stream instanceof PushbackInputStream) |
| pb = (PushbackInputStream) stream; |
| else |
| pb = new PushbackInputStream(stream, MAXPUSHBACK); |
| |
| // |
| // See if we can figure out the character encoding used |
| // in this file by peeking at the first few bytes. |
| // |
| buf = new byte[4]; |
| len = pb.read(buf); |
| if (len > 0) |
| pb.unread(buf, 0, len); |
| |
| if (len == 4) |
| switch (buf[0] & 0x0ff) { |
| case 0: |
| // 00 3c 00 3f == illegal UTF-16 big-endian |
| if (buf[1] == 0x3c && buf[2] == 0x00 && buf[3] == 0x3f) { |
| setEncoding(pb, "UnicodeBig"); |
| return; |
| } |
| // else it's probably UCS-4 |
| break; |
| |
| case '<': // 0x3c: the most common cases! |
| switch (buf[1] & 0x0ff) { |
| // First character is '<'; could be XML without |
| // an XML directive such as "<hello>", "<!-- ...", |
| // and so on. |
| default: |
| break; |
| |
| // 3c 00 3f 00 == illegal UTF-16 little endian |
| case 0x00: |
| if (buf[2] == 0x3f && buf[3] == 0x00) { |
| setEncoding(pb, "UnicodeLittle"); |
| return; |
| } |
| // else probably UCS-4 |
| break; |
| |
| // 3c 3f 78 6d == ASCII and supersets '<?xm' |
| case '?': |
| if (buf[2] != 'x' || buf[3] != 'm') |
| break; |
| // |
| // One of several encodings could be used: |
| // Shift-JIS, ASCII, UTF-8, ISO-8859-*, etc |
| // |
| useEncodingDecl(pb, "UTF8"); |
| return; |
| } |
| break; |
| |
| // 4c 6f a7 94 ... some EBCDIC code page |
| case 0x4c: |
| if (buf[1] == 0x6f |
| && (0x0ff & buf[2]) == 0x0a7 |
| && (0x0ff & buf[3]) == 0x094) { |
| useEncodingDecl(pb, "CP037"); |
| return; |
| } |
| // whoops, treat as UTF-8 |
| break; |
| |
| // UTF-16 big-endian |
| case 0xfe: |
| if ((buf[1] & 0x0ff) != 0xff) |
| break; |
| setEncoding(pb, "UTF-16"); |
| return; |
| |
| // UTF-16 little-endian |
| case 0xff: |
| if ((buf[1] & 0x0ff) != 0xfe) |
| break; |
| setEncoding(pb, "UTF-16"); |
| return; |
| |
| // default ... no XML declaration |
| default: |
| break; |
| } |
| |
| // |
| // If all else fails, assume XML without a declaration, and |
| // using UTF-8 encoding. |
| // |
| setEncoding(pb, "UTF-8"); |
| } |
| |
| /* |
| * Read the encoding decl on the stream, knowing that it should |
| * be readable using the specified encoding (basically, ASCII or |
| * EBCDIC). The body of the document may use a wider range of |
| * characters than the XML/Text decl itself, so we switch to use |
| * the specified encoding as soon as we can. (ASCII is a subset |
| * of UTF-8, ISO-8859-*, ISO-2022-JP, EUC-JP, and more; EBCDIC |
| * has a variety of "code pages" that have these characters as |
| * a common subset.) |
| */ |
| private void useEncodingDecl(PushbackInputStream pb, String encoding) |
| throws IOException { |
| byte buffer [] = new byte[MAXPUSHBACK]; |
| int len; |
| Reader r; |
| int c; |
| |
| // |
| // Buffer up a bunch of input, and set up to read it in |
| // the specified encoding ... we can skip the first four |
| // bytes since we know that "<?xm" was read to determine |
| // what encoding to use! |
| // |
| len = pb.read(buffer, 0, buffer.length); |
| pb.unread(buffer, 0, len); |
| r = new InputStreamReader(new ByteArrayInputStream(buffer, 4, len), |
| encoding); |
| |
| // |
| // Next must be "l" (and whitespace) else we conclude |
| // error and choose UTF-8. |
| // |
| if ((c = r.read()) != 'l') { |
| setEncoding(pb, "UTF-8"); |
| return; |
| } |
| |
| // |
| // Then, we'll skip any |
| // S version="..." [or single quotes] |
| // bit and get any subsequent |
| // S encoding="..." [or single quotes] |
| // |
| // We put an arbitrary size limit on how far we read; lots |
| // of space will break this algorithm. |
| // |
| StringBuffer buf = new StringBuffer(); |
| StringBuffer keyBuf = null; |
| String key = null; |
| boolean sawEq = false; |
| char quoteChar = 0; |
| boolean sawQuestion = false; |
| |
| XmlDecl: |
| for (int i = 0; i < MAXPUSHBACK - 5; ++i) { |
| if ((c = r.read()) == -1) |
| break; |
| |
| // ignore whitespace before/between "key = 'value'" |
| if (c == ' ' || c == '\t' || c == '\n' || c == '\r') |
| continue; |
| |
| // ... but require at least a little! |
| if (i == 0) |
| break; |
| |
| // terminate the loop ASAP |
| if (c == '?') |
| sawQuestion = true; |
| else if (sawQuestion) { |
| if (c == '>') |
| break; |
| sawQuestion = false; |
| } |
| |
| // did we get the "key =" bit yet? |
| if (key == null || !sawEq) { |
| if (keyBuf == null) { |
| if (Character.isWhitespace((char) c)) |
| continue; |
| keyBuf = buf; |
| buf.setLength(0); |
| buf.append((char) c); |
| sawEq = false; |
| } else if (Character.isWhitespace((char) c)) { |
| key = keyBuf.toString(); |
| } else if (c == '=') { |
| if (key == null) |
| key = keyBuf.toString(); |
| sawEq = true; |
| keyBuf = null; |
| quoteChar = 0; |
| } else |
| keyBuf.append((char) c); |
| continue; |
| } |
| |
| // space before quoted value |
| if (Character.isWhitespace((char) c)) |
| continue; |
| if (c == '"' || c == '\'') { |
| if (quoteChar == 0) { |
| quoteChar = (char) c; |
| buf.setLength(0); |
| continue; |
| } else if (c == quoteChar) { |
| if ("encoding".equals(key)) { |
| assignedEncoding = buf.toString(); |
| |
| // [81] Encname ::= [A-Za-z] ([A-Za-z0-9._]|'-')* |
| for (i = 0; i < assignedEncoding.length(); i++) { |
| c = assignedEncoding.charAt(i); |
| if ((c >= 'A' && c <= 'Z') |
| || (c >= 'a' && c <= 'z')) |
| continue; |
| if (i == 0) |
| break XmlDecl; |
| if (i > 0 && (c == '-' |
| || (c >= '0' && c <= '9') |
| || c == '.' || c == '_')) |
| continue; |
| // map illegal names to UTF-8 default |
| break XmlDecl; |
| } |
| |
| setEncoding(pb, assignedEncoding); |
| return; |
| |
| } else { |
| key = null; |
| continue; |
| } |
| } |
| } |
| buf.append((char) c); |
| } |
| |
| setEncoding(pb, "UTF-8"); |
| } |
| |
| private void setEncoding(InputStream stream, String encoding) |
| throws IOException { |
| assignedEncoding = encoding; |
| in = createReader(stream, encoding); |
| } |
| |
| /** |
| * Reads the number of characters read into the buffer, or -1 on EOF. |
| */ |
| public int read(char buf [], int off, int len) throws IOException { |
| int val; |
| |
| if (closed) |
| return -1; // throw new IOException ("closed"); |
| val = in.read(buf, off, len); |
| if (val == -1) |
| close(); |
| return val; |
| } |
| |
| /** |
| * Reads a single character. |
| */ |
| public int read() throws IOException { |
| int val; |
| |
| if (closed) |
| throw new IOException("closed"); |
| val = in.read(); |
| if (val == -1) |
| close(); |
| return val; |
| } |
| |
| /** |
| * Returns true iff the reader supports mark/reset. |
| */ |
| public boolean markSupported() { |
| return in == null ? false : in.markSupported(); |
| } |
| |
| /** |
| * Sets a mark allowing a limited number of characters to |
| * be "peeked", by reading and then resetting. |
| * |
| * @param value how many characters may be "peeked". |
| */ |
| public void mark(int value) throws IOException { |
| if (in != null) in.mark(value); |
| } |
| |
| /** |
| * Resets the current position to the last marked position. |
| */ |
| public void reset() throws IOException { |
| if (in != null) in.reset(); |
| } |
| |
| /** |
| * Skips a specified number of characters. |
| */ |
| public long skip(long value) throws IOException { |
| return in == null ? 0 : in.skip(value); |
| } |
| |
| /** |
| * Returns true iff input characters are known to be ready. |
| */ |
| public boolean ready() throws IOException { |
| return in == null ? false : in.ready(); |
| } |
| |
| /** |
| * Closes the reader. |
| */ |
| public void close() throws IOException { |
| if (closed) |
| return; |
| in.close(); |
| in = null; |
| closed = true; |
| } |
| |
| // |
| // Delegating to a converter module will always be slower than |
| // direct conversion. Use a similar approach for any other |
| // readers that need to be particularly fast; only block I/O |
| // speed matters to this package. For UTF-16, separate readers |
| // for big and little endian streams make a difference, too; |
| // fewer conditionals in the critical path! |
| // |
| static abstract class BaseReader extends Reader { |
| protected InputStream instream; |
| protected byte buffer []; |
| protected int start, finish; |
| |
| BaseReader(InputStream stream) { |
| super(stream); |
| |
| instream = stream; |
| buffer = new byte[8192]; |
| } |
| |
| public boolean ready() throws IOException { |
| return instream == null |
| || (finish - start) > 0 |
| || instream.available() != 0; |
| } |
| |
| // caller shouldn't read again |
| public void close() throws IOException { |
| if (instream != null) { |
| instream.close(); |
| start = finish = 0; |
| buffer = null; |
| instream = null; |
| } |
| } |
| } |
| |
| // |
| // We want this reader, to make the default encoding be as fast |
| // as we can make it. JDK's "UTF8" (not "UTF-8" till JDK 1.2) |
| // InputStreamReader works, but 20+% slower speed isn't OK for |
| // the default/primary encoding. |
| // |
| static final class Utf8Reader extends BaseReader { |
| // 2nd half of UTF-8 surrogate pair |
| private char nextChar; |
| |
| Utf8Reader(InputStream stream) { |
| super(stream); |
| } |
| |
| public int read(char buf [], int offset, int len) throws IOException { |
| int i = 0, c = 0; |
| |
| if (len <= 0) |
| return 0; |
| |
| // Consume remaining half of any surrogate pair immediately |
| if (nextChar != 0) { |
| buf[offset + i++] = nextChar; |
| nextChar = 0; |
| } |
| |
| while (i < len) { |
| // stop or read data if needed |
| if (finish <= start) { |
| if (instream == null) { |
| c = -1; |
| break; |
| } |
| start = 0; |
| finish = instream.read(buffer, 0, buffer.length); |
| if (finish <= 0) { |
| this.close(); |
| c = -1; |
| break; |
| } |
| } |
| |
| // |
| // RFC 2279 describes UTF-8; there are six encodings. |
| // Each encoding takes a fixed number of characters |
| // (1-6 bytes) and is flagged by a bit pattern in the |
| // first byte. The five and six byte-per-character |
| // encodings address characters which are disallowed |
| // in XML documents, as do some four byte ones. |
| // |
| |
| // |
| // Single byte == ASCII. Common; optimize. |
| // |
| c = buffer[start] & 0x0ff; |
| if ((c & 0x80) == 0x00) { |
| // 0x0000 <= c <= 0x007f |
| start++; |
| buf[offset + i++] = (char) c; |
| continue; |
| } |
| |
| // |
| // Multibyte chars -- check offsets optimistically, |
| // ditto the "10xx xxxx" format for subsequent bytes |
| // |
| int off = start; |
| |
| try { |
| // 2 bytes |
| if ((buffer[off] & 0x0E0) == 0x0C0) { |
| c = (buffer[off++] & 0x1f) << 6; |
| c += buffer[off++] & 0x3f; |
| |
| // 0x0080 <= c <= 0x07ff |
| |
| // 3 bytes |
| } else if ((buffer[off] & 0x0F0) == 0x0E0) { |
| c = (buffer[off++] & 0x0f) << 12; |
| c += (buffer[off++] & 0x3f) << 6; |
| c += buffer[off++] & 0x3f; |
| |
| // 0x0800 <= c <= 0xffff |
| |
| // 4 bytes |
| } else if ((buffer[off] & 0x0f8) == 0x0F0) { |
| c = (buffer[off++] & 0x07) << 18; |
| c += (buffer[off++] & 0x3f) << 12; |
| c += (buffer[off++] & 0x3f) << 6; |
| c += buffer[off++] & 0x3f; |
| |
| // 0x0001 0000 <= c <= 0x001f ffff |
| |
| // Unicode supports c <= 0x0010 ffff ... |
| if (c > 0x0010ffff) |
| throw new CharConversionException("UTF-8 encoding of character 0x00" |
| + Integer.toHexString(c) |
| + " can't be converted to Unicode."); |
| |
| // Convert UCS-4 char to surrogate pair (UTF-16) |
| c -= 0x10000; |
| nextChar = (char) (0xDC00 + (c & 0x03ff)); |
| c = 0xD800 + (c >> 10); |
| |
| // 5 and 6 byte versions are XML WF errors, but |
| // typically come from mislabeled encodings |
| } else |
| throw new CharConversionException("Unconvertible UTF-8 character" |
| + " beginning with 0x" |
| + Integer.toHexString(buffer[start] & 0xff)); |
| |
| } catch (ArrayIndexOutOfBoundsException e) { |
| // off > length && length >= buffer.length |
| c = 0; |
| } |
| |
| // |
| // if the buffer held only a partial character, |
| // compact it and try to read the rest of the |
| // character. worst case involves three |
| // single-byte reads -- quite rare. |
| // |
| if (off > finish) { |
| System.arraycopy(buffer, start, |
| buffer, 0, finish - start); |
| finish -= start; |
| start = 0; |
| off = instream.read(buffer, finish, |
| buffer.length - finish); |
| if (off < 0) { |
| this.close(); |
| throw new CharConversionException("Partial UTF-8 char"); |
| } |
| finish += off; |
| continue; |
| } |
| |
| // |
| // check the format of the non-initial bytes |
| // |
| for (start++; start < off; start++) { |
| if ((buffer[start] & 0xC0) != 0x80) { |
| this.close(); |
| throw new CharConversionException("Malformed UTF-8 char -- " |
| + "is an XML encoding declaration missing?"); |
| } |
| } |
| |
| // |
| // If this needed a surrogate pair, consume ASAP |
| // |
| buf[offset + i++] = (char) c; |
| if (nextChar != 0 && i < len) { |
| buf[offset + i++] = nextChar; |
| nextChar = 0; |
| } |
| } |
| if (i > 0) |
| return i; |
| return (c == -1) ? -1 : 0; |
| } |
| } |
| |
| // |
| // We want ASCII and ISO-8859 Readers since they're the most common |
| // encodings in the US and Europe, and we don't want performance |
| // regressions for them. They're also easy to implement efficiently, |
| // since they're bitmask subsets of UNICODE. |
| // |
| // XXX haven't benchmarked these readers vs what we get out of JDK. |
| // |
| static final class AsciiReader extends BaseReader { |
| AsciiReader(InputStream in) { |
| super(in); |
| } |
| |
| public int read(char buf [], int offset, int len) throws IOException { |
| int i, c; |
| |
| if (instream == null) |
| return -1; |
| |
| for (i = 0; i < len; i++) { |
| if (start >= finish) { |
| start = 0; |
| finish = instream.read(buffer, 0, buffer.length); |
| if (finish <= 0) { |
| if (finish <= 0) |
| this.close(); |
| break; |
| } |
| } |
| c = buffer[start++]; |
| if ((c & 0x80) != 0) |
| throw new CharConversionException("Illegal ASCII character, 0x" |
| + Integer.toHexString(c & 0xff)); |
| buf[offset + i] = (char) c; |
| } |
| if (i == 0 && finish <= 0) |
| return -1; |
| return i; |
| } |
| } |
| |
| static final class Iso8859_1Reader extends BaseReader { |
| Iso8859_1Reader(InputStream in) { |
| super(in); |
| } |
| |
| public int read(char buf [], int offset, int len) throws IOException { |
| int i; |
| |
| if (instream == null) |
| return -1; |
| |
| for (i = 0; i < len; i++) { |
| if (start >= finish) { |
| start = 0; |
| finish = instream.read(buffer, 0, buffer.length); |
| if (finish <= 0) { |
| if (finish <= 0) |
| this.close(); |
| break; |
| } |
| } |
| buf[offset + i] = (char) (0x0ff & buffer[start++]); |
| } |
| if (i == 0 && finish <= 0) |
| return -1; |
| return i; |
| } |
| } |
| } |
