Mercurial > jdk8-mips64-public > jaxws / file revision

 /*

  * 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;

         }

     }

 }