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/*
 * 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.apache.org.  For more
 * information on the Apache Software Foundation, please see
 * .
 */
package org.apache.jasper.xmlparser;

import static org.apache.jasper.JasperMessages.MESSAGES;

import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.Locale;

import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.compiler.ErrorDispatcher;
import org.apache.jasper.compiler.JspUtil;
import org.apache.tomcat.util.scan.Jar;

public class XMLEncodingDetector {

    private InputStream stream;
    private String encoding;
    private boolean isEncodingSetInProlog;
    private boolean isBomPresent;
    private int skip;
    private Boolean isBigEndian;
    private Reader reader;

    // org.apache.xerces.impl.XMLEntityManager fields
    private static final int DEFAULT_BUFFER_SIZE = 2048;
    private static final int DEFAULT_XMLDECL_BUFFER_SIZE = 64;
    private final SymbolTable fSymbolTable;
    private final XMLEncodingDetector fCurrentEntity;
    private int fBufferSize = DEFAULT_BUFFER_SIZE;

    // org.apache.xerces.impl.XMLEntityManager.ScannedEntity fields
    private char[] ch = new char[DEFAULT_BUFFER_SIZE];
    private int position;
    private int count;

    // org.apache.xerces.impl.XMLScanner fields
    private final XMLString fString = new XMLString();
    private final XMLStringBuffer fStringBuffer = new XMLStringBuffer();
    private final XMLStringBuffer fStringBuffer2 = new XMLStringBuffer();
    private static final String fVersionSymbol = "version";
    private static final String fEncodingSymbol = "encoding";
    private static final String fStandaloneSymbol = "standalone";

    // org.apache.xerces.impl.XMLDocumentFragmentScannerImpl fields
    private final String[] fStrings = new String[3];

    private ErrorDispatcher err;

    /**
     * Constructor
     */
    public XMLEncodingDetector() {
        fSymbolTable = new SymbolTable();
        fCurrentEntity = this;
    }

    /**
     * Autodetects the encoding of the XML document supplied by the given
     * input stream.
     *
     * Encoding autodetection is done according to the XML 1.0 specification,
     * Appendix F.1: Detection Without External Encoding Information.
     *
     * @return Two-element array, where the first element (of type
     * java.lang.String) contains the name of the (auto)detected encoding, and
     * the second element (of type java.lang.Boolean) specifies whether the
     * encoding was specified using the 'encoding' attribute of an XML prolog
     * (TRUE) or autodetected (FALSE).
     */
    public static Object[] getEncoding(String fname, Jar jar,
                                       JspCompilationContext ctxt,
                                       ErrorDispatcher err)
        throws IOException, JasperException
    {
        InputStream inStream = JspUtil.getInputStream(fname, jar, ctxt);
        XMLEncodingDetector detector = new XMLEncodingDetector();
        Object[] ret = detector.getEncoding(inStream, err);
        inStream.close();

        return ret;
    }

    private Object[] getEncoding(InputStream in, ErrorDispatcher err)
        throws IOException, JasperException
    {
        this.stream = in;
        this.err=err;
        createInitialReader();
        scanXMLDecl();

        return new Object[] { this.encoding,
                              Boolean.valueOf(this.isEncodingSetInProlog),
                              Boolean.valueOf(this.isBomPresent),
                              Integer.valueOf(this.skip) };
    }

    // stub method
    void endEntity() {
    }

    // Adapted from:
    // org.apache.xerces.impl.XMLEntityManager.startEntity()
    private void createInitialReader() throws IOException, JasperException {

	// wrap this stream in RewindableInputStream
	stream = new RewindableInputStream(stream);

	// perform auto-detect of encoding if necessary
	if (encoding == null) {
	    // read first four bytes and determine encoding
	    final byte[] b4 = new byte[4];
	    int count = 0;
	    for (; count<4; count++ ) {
		b4[count] = (byte)stream.read();
	    }
	    if (count == 4) {
		Object [] encodingDesc = getEncodingName(b4, count);
		encoding = (String)(encodingDesc[0]);
		isBigEndian = (Boolean)(encodingDesc[1]);

        if (encodingDesc.length > 3) {
                    isBomPresent = ((Boolean)(encodingDesc[2])).booleanValue();
                    skip = ((Integer)(encodingDesc[3])).intValue();
        } else {
            isBomPresent = true;
                    skip = ((Integer)(encodingDesc[2])).intValue();
        }

		stream.reset();
		// Special case UTF-8 files with BOM created by Microsoft
		// tools. It's more efficient to consume the BOM than make
		// the reader perform extra checks. -Ac
		if (count > 2 && encoding.equals("UTF-8")) {
		    int b0 = b4[0] & 0xFF;
		    int b1 = b4[1] & 0xFF;
		    int b2 = b4[2] & 0xFF;
		    if (b0 == 0xEF && b1 == 0xBB && b2 == 0xBF) {
			// ignore first three bytes...
                        long skipped = stream.skip(3);
                        if (skipped != 3) {
                            throw new IOException("Skip BOM fail");
                        }
		    }
		}
		reader = createReader(stream, encoding, isBigEndian);
	    } else {
		reader = createReader(stream, encoding, isBigEndian);
	    }
	}
    }

    // Adapted from:
    // org.apache.xerces.impl.XMLEntityManager.createReader
    /**
     * Creates a reader capable of reading the given input stream in
     * the specified encoding.
     *
     * @param inputStream  The input stream.
     * @param encoding     The encoding name that the input stream is
     *                     encoded using. If the user has specified that
     *                     Java encoding names are allowed, then the
     *                     encoding name may be a Java encoding name;
     *                     otherwise, it is an ianaEncoding name.
     * @param isBigEndian   For encodings (like uCS-4), whose names cannot
     *                      specify a byte order, this tells whether the order
     *                      is bigEndian. null means unknown or not relevant.
     *
     * @return Returns a reader.
     */
    private Reader createReader(InputStream inputStream, String encoding,
				Boolean isBigEndian)
                throws IOException, JasperException {

        // normalize encoding name
        if (encoding == null) {
            encoding = "UTF-8";
        }

        // try to use an optimized reader
        String ENCODING = encoding.toUpperCase(Locale.ENGLISH);
        if (ENCODING.equals("UTF-8")) {
            return new UTF8Reader(inputStream, fBufferSize);
        }
        if (ENCODING.equals("US-ASCII")) {
            return new ASCIIReader(inputStream, fBufferSize);
        }
        if (ENCODING.equals("ISO-10646-UCS-4")) {
            if (isBigEndian != null) {
                boolean isBE = isBigEndian.booleanValue();
                if (isBE) {
                    return new UCSReader(inputStream, UCSReader.UCS4BE);
                } else {
                    return new UCSReader(inputStream, UCSReader.UCS4LE);
                }
            } else {
                err.jspError(MESSAGES.unsupportedByteOrderForEncoding(encoding));
            }
        }
        if (ENCODING.equals("ISO-10646-UCS-2")) {
            if (isBigEndian != null) { // sould never happen with this encoding...
                boolean isBE = isBigEndian.booleanValue();
                if (isBE) {
                    return new UCSReader(inputStream, UCSReader.UCS2BE);
                } else {
                    return new UCSReader(inputStream, UCSReader.UCS2LE);
                }
            } else {
                err.jspError(MESSAGES.unsupportedByteOrderForEncoding(encoding));
            }
        }

        // check for valid name
        boolean validIANA = XMLChar.isValidIANAEncoding(encoding);
        if (!validIANA) {
            err.jspError(MESSAGES.invalidEncodingDeclared(encoding));
            // NOTE: AndyH suggested that, on failure, we use ISO Latin 1
            //       because every byte is a valid ISO Latin 1 character.
            //       It may not translate correctly but if we failed on
            //       the encoding anyway, then we're expecting the content
            //       of the document to be bad. This will just prevent an
            //       invalid UTF-8 sequence to be detected. This is only
            //       important when continue-after-fatal-error is turned
            //       on. -Ac
            encoding = "ISO-8859-1";
        }

        // try to use a Java reader
        String javaEncoding = EncodingMap.getIANA2JavaMapping(ENCODING);
        if (javaEncoding == null) {
                err.jspError(MESSAGES.invalidEncodingDeclared(encoding));
                // see comment above.
                javaEncoding = "ISO8859_1";
            }
        return new InputStreamReader(inputStream, javaEncoding);

    } // createReader(InputStream,String, Boolean): Reader

    // Adapted from:
    // org.apache.xerces.impl.XMLEntityManager.getEncodingName
    /**
     * Returns the IANA encoding name that is auto-detected from
     * the bytes specified, with the endian-ness of that encoding where
     * appropriate.
     *
     * @param b4    The first four bytes of the input.
     * @param count The number of bytes actually read.
     * @return a 2-element array:  the first element, an IANA-encoding string,
     *  the second element a Boolean which is true iff the document is big
     *  endian, false if it's little-endian, and null if the distinction isn't
     *  relevant.
     */
    private Object[] getEncodingName(byte[] b4, int count) {

        if (count < 2) {
            return new Object[]{"UTF-8", null, Boolean.FALSE, Integer.valueOf(0)};
        }

        // UTF-16, with BOM
        int b0 = b4[0] & 0xFF;
        int b1 = b4[1] & 0xFF;
        if (b0 == 0xFE && b1 == 0xFF) {
            // UTF-16, big-endian
            return new Object [] {"UTF-16BE", Boolean.TRUE, Integer.valueOf(2)};
        }
        if (b0 == 0xFF && b1 == 0xFE) {
            // UTF-16, little-endian
            return new Object [] {"UTF-16LE", Boolean.FALSE, Integer.valueOf(2)};
        }

        // default to UTF-8 if we don't have enough bytes to make a
        // good determination of the encoding
        if (count < 3) {
            return new Object [] {"UTF-8", null, Boolean.FALSE, Integer.valueOf(0)};
        }

        // UTF-8 with a BOM
        int b2 = b4[2] & 0xFF;
        if (b0 == 0xEF && b1 == 0xBB && b2 == 0xBF) {
            return new Object [] {"UTF-8", null, Integer.valueOf(3)};
        }

        // default to UTF-8 if we don't have enough bytes to make a
        // good determination of the encoding
        if (count < 4) {
            return new Object [] {"UTF-8", null, Integer.valueOf(0)};
        }

        // other encodings
        int b3 = b4[3] & 0xFF;
        if (b0 == 0x00 && b1 == 0x00 && b2 == 0x00 && b3 == 0x3C) {
            // UCS-4, big endian (1234)
            return new Object [] {"ISO-10646-UCS-4", Boolean.TRUE, Integer.valueOf(4)};
        }
        if (b0 == 0x3C && b1 == 0x00 && b2 == 0x00 && b3 == 0x00) {
            // UCS-4, little endian (4321)
            return new Object [] {"ISO-10646-UCS-4", Boolean.FALSE, Integer.valueOf(4)};
        }
        if (b0 == 0x00 && b1 == 0x00 && b2 == 0x3C && b3 == 0x00) {
            // UCS-4, unusual octet order (2143)
            // REVISIT: What should this be?
            return new Object [] {"ISO-10646-UCS-4", null, Integer.valueOf(4)};
        }
        if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x00) {
            // UCS-4, unusual octect order (3412)
            // REVISIT: What should this be?
            return new Object [] {"ISO-10646-UCS-4", null, Integer.valueOf(4)};
        }
        if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x3F) {
            // UTF-16, big-endian, no BOM
            // (or could turn out to be UCS-2...
            // REVISIT: What should this be?
            return new Object [] {"UTF-16BE", Boolean.TRUE, Integer.valueOf(4)};
        }
        if (b0 == 0x3C && b1 == 0x00 && b2 == 0x3F && b3 == 0x00) {
            // UTF-16, little-endian, no BOM
            // (or could turn out to be UCS-2...
            return new Object [] {"UTF-16LE", Boolean.FALSE, Integer.valueOf(4)};
        }
        if (b0 == 0x4C && b1 == 0x6F && b2 == 0xA7 && b3 == 0x94) {
            // EBCDIC
            // a la xerces1, return CP037 instead of EBCDIC here
            return new Object [] {"CP037", null, Integer.valueOf(4)};
        }

        // default encoding
        return new Object [] {"UTF-8", null, Boolean.FALSE, Integer.valueOf(0)};

    }

    // Adapted from:
    // org.apache.xerces.impl.XMLEntityManager.EntityScanner.isExternal
    /** Returns true if the current entity being scanned is external. */
    public boolean isExternal() {
	return true;
    }

    // Adapted from:
    // org.apache.xerces.impl.XMLEntityManager.EntityScanner.peekChar
    /**
     * Returns the next character on the input.
     * 

* Note: The character is not consumed. * * @throws IOException Thrown if i/o error occurs. * @throws EOFException Thrown on end of file. */ public int peekChar() throws IOException { // load more characters, if needed if (fCurrentEntity.position == fCurrentEntity.count) { load(0, true); } // peek at character int c = fCurrentEntity.ch[fCurrentEntity.position]; // return peeked character if (fCurrentEntity.isExternal()) { return c != '\r' ? c : '\n'; } else { return c; } } // peekChar():int // Adapted from: // org.apache.xerces.impl.XMLEntityManager.EntityScanner.scanChar /** * Returns the next character on the input. *

* Note: The character is consumed. * * @throws IOException Thrown if i/o error occurs. * @throws EOFException Thrown on end of file. */ public int scanChar() throws IOException { // load more characters, if needed if (fCurrentEntity.position == fCurrentEntity.count) { load(0, true); } // scan character int c = fCurrentEntity.ch[fCurrentEntity.position++]; boolean external = false; if (c == '\n' || (c == '\r' && (external = fCurrentEntity.isExternal()))) { if (fCurrentEntity.position == fCurrentEntity.count) { fCurrentEntity.ch[0] = (char)c; load(1, false); } if (c == '\r' && external) { if (fCurrentEntity.ch[fCurrentEntity.position++] != '\n') { fCurrentEntity.position--; } c = '\n'; } } // return character that was scanned return c; } // Adapted from: // org.apache.xerces.impl.XMLEntityManager.EntityScanner.scanName /** * Returns a string matching the Name production appearing immediately * on the input as a symbol, or null if no Name string is present. *

* Note: The Name characters are consumed. *

* Note: The string returned must be a symbol. The * SymbolTable can be used for this purpose. * * @throws IOException Thrown if i/o error occurs. * @throws EOFException Thrown on end of file. * * @see SymbolTable * @see XMLChar#isName * @see XMLChar#isNameStart */ public String scanName() throws IOException { // load more characters, if needed if (fCurrentEntity.position == fCurrentEntity.count) { load(0, true); } // scan name int offset = fCurrentEntity.position; if (XMLChar.isNameStart(fCurrentEntity.ch[offset])) { if (++fCurrentEntity.position == fCurrentEntity.count) { fCurrentEntity.ch[0] = fCurrentEntity.ch[offset]; offset = 0; if (load(1, false)) { String symbol = fSymbolTable.addSymbol(fCurrentEntity.ch, 0, 1); return symbol; } } while (XMLChar.isName(fCurrentEntity.ch[fCurrentEntity.position])) { if (++fCurrentEntity.position == fCurrentEntity.count) { int length = fCurrentEntity.position - offset; if (length == fBufferSize) { // bad luck we have to resize our buffer char[] tmp = new char[fBufferSize * 2]; System.arraycopy(fCurrentEntity.ch, offset, tmp, 0, length); fCurrentEntity.ch = tmp; fBufferSize *= 2; } else { System.arraycopy(fCurrentEntity.ch, offset, fCurrentEntity.ch, 0, length); } offset = 0; if (load(length, false)) { break; } } } } int length = fCurrentEntity.position - offset; // return name String symbol = null; if (length > 0) { symbol = fSymbolTable.addSymbol(fCurrentEntity.ch, offset, length); } return symbol; } // Adapted from: // org.apache.xerces.impl.XMLEntityManager.EntityScanner.scanLiteral /** * Scans a range of attribute value data, setting the fields of the * XMLString structure, appropriately. *

* Note: The characters are consumed. *

* Note: This method does not guarantee to return * the longest run of attribute value data. This method may return * before the quote character due to reaching the end of the input * buffer or any other reason. *

* Note: The fields contained in the XMLString * structure are not guaranteed to remain valid upon subsequent calls * to the entity scanner. Therefore, the caller is responsible for * immediately using the returned character data or making a copy of * the character data. * * @param quote The quote character that signifies the end of the * attribute value data. * @param content The content structure to fill. * * @return Returns the next character on the input, if known. This * value may be -1 but this does note designate * end of file. * * @throws IOException Thrown if i/o error occurs. * @throws EOFException Thrown on end of file. */ public int scanLiteral(int quote, XMLString content) throws IOException { // load more characters, if needed if (fCurrentEntity.position == fCurrentEntity.count) { load(0, true); } else if (fCurrentEntity.position == fCurrentEntity.count - 1) { fCurrentEntity.ch[0] = fCurrentEntity.ch[fCurrentEntity.count - 1]; load(1, false); fCurrentEntity.position = 0; } // normalize newlines int offset = fCurrentEntity.position; int c = fCurrentEntity.ch[offset]; int newlines = 0; boolean external = fCurrentEntity.isExternal(); if (c == '\n' || (c == '\r' && external)) { do { c = fCurrentEntity.ch[fCurrentEntity.position++]; if (c == '\r' && external) { newlines++; if (fCurrentEntity.position == fCurrentEntity.count) { offset = 0; fCurrentEntity.position = newlines; if (load(newlines, false)) { break; } } if (fCurrentEntity.ch[fCurrentEntity.position] == '\n') { fCurrentEntity.position++; offset++; } /*** NEWLINE NORMALIZATION ***/ else { newlines++; } /***/ } else if (c == '\n') { newlines++; if (fCurrentEntity.position == fCurrentEntity.count) { offset = 0; fCurrentEntity.position = newlines; if (load(newlines, false)) { break; } } /*** NEWLINE NORMALIZATION *** if (fCurrentEntity.ch[fCurrentEntity.position] == '\r' && external) { fCurrentEntity.position++; offset++; } /***/ } else { fCurrentEntity.position--; break; } } while (fCurrentEntity.position < fCurrentEntity.count - 1); for (int i = offset; i < fCurrentEntity.position; i++) { fCurrentEntity.ch[i] = '\n'; } int length = fCurrentEntity.position - offset; if (fCurrentEntity.position == fCurrentEntity.count - 1) { content.setValues(fCurrentEntity.ch, offset, length); return -1; } } // scan literal value while (fCurrentEntity.position < fCurrentEntity.count) { c = fCurrentEntity.ch[fCurrentEntity.position++]; if (c == quote || c == '%' || !XMLChar.isContent(c)) { fCurrentEntity.position--; break; } } int length = fCurrentEntity.position - offset; content.setValues(fCurrentEntity.ch, offset, length); // return next character if (fCurrentEntity.position != fCurrentEntity.count) { c = fCurrentEntity.ch[fCurrentEntity.position]; } else { c = -1; } return c; } /** * Scans a range of character data up to the specified delimiter, * setting the fields of the XMLString structure, appropriately. *

* Note: The characters are consumed. *

* Note: This assumes that the internal buffer is * at least the same size, or bigger, than the length of the delimiter * and that the delimiter contains at least one character. *

* Note: This method does not guarantee to return * the longest run of character data. This method may return before * the delimiter due to reaching the end of the input buffer or any * other reason. *

* Note: The fields contained in the XMLString * structure are not guaranteed to remain valid upon subsequent calls * to the entity scanner. Therefore, the caller is responsible for * immediately using the returned character data or making a copy of * the character data. * * @param delimiter The string that signifies the end of the character * data to be scanned. * @param buffer The data structure to fill. * * @return Returns true if there is more data to scan, false otherwise. * * @throws IOException Thrown if i/o error occurs. * @throws EOFException Thrown on end of file. */ public boolean scanData(String delimiter, XMLStringBuffer buffer) throws IOException { boolean done = false; int delimLen = delimiter.length(); char charAt0 = delimiter.charAt(0); boolean external = fCurrentEntity.isExternal(); do { // load more characters, if needed if (fCurrentEntity.position == fCurrentEntity.count) { load(0, true); } else if (fCurrentEntity.position >= fCurrentEntity.count - delimLen) { System.arraycopy(fCurrentEntity.ch, fCurrentEntity.position, fCurrentEntity.ch, 0, fCurrentEntity.count - fCurrentEntity.position); load(fCurrentEntity.count - fCurrentEntity.position, false); fCurrentEntity.position = 0; } if (fCurrentEntity.position >= fCurrentEntity.count - delimLen) { // something must be wrong with the input: e.g., file ends an // unterminated comment int length = fCurrentEntity.count - fCurrentEntity.position; buffer.append (fCurrentEntity.ch, fCurrentEntity.position, length); fCurrentEntity.position = fCurrentEntity.count; load(0,true); return false; } // normalize newlines int offset = fCurrentEntity.position; int c = fCurrentEntity.ch[offset]; int newlines = 0; if (c == '\n' || (c == '\r' && external)) { do { c = fCurrentEntity.ch[fCurrentEntity.position++]; if (c == '\r' && external) { newlines++; if (fCurrentEntity.position == fCurrentEntity.count) { offset = 0; fCurrentEntity.position = newlines; if (load(newlines, false)) { break; } } if (fCurrentEntity.ch[fCurrentEntity.position] == '\n') { fCurrentEntity.position++; offset++; } /*** NEWLINE NORMALIZATION ***/ else { newlines++; } } else if (c == '\n') { newlines++; if (fCurrentEntity.position == fCurrentEntity.count) { offset = 0; fCurrentEntity.position = newlines; fCurrentEntity.count = newlines; if (load(newlines, false)) { break; } } } else { fCurrentEntity.position--; break; } } while (fCurrentEntity.position < fCurrentEntity.count - 1); for (int i = offset; i < fCurrentEntity.position; i++) { fCurrentEntity.ch[i] = '\n'; } int length = fCurrentEntity.position - offset; if (fCurrentEntity.position == fCurrentEntity.count - 1) { buffer.append(fCurrentEntity.ch, offset, length); return true; } } // iterate over buffer looking for delimiter OUTER: while (fCurrentEntity.position < fCurrentEntity.count) { c = fCurrentEntity.ch[fCurrentEntity.position++]; if (c == charAt0) { // looks like we just hit the delimiter int delimOffset = fCurrentEntity.position - 1; for (int i = 1; i < delimLen; i++) { if (fCurrentEntity.position == fCurrentEntity.count) { fCurrentEntity.position -= i; break OUTER; } c = fCurrentEntity.ch[fCurrentEntity.position++]; if (delimiter.charAt(i) != c) { fCurrentEntity.position--; break; } } if (fCurrentEntity.position == delimOffset + delimLen) { done = true; break; } } else if (c == '\n' || (external && c == '\r')) { fCurrentEntity.position--; break; } else if (XMLChar.isInvalid(c)) { fCurrentEntity.position--; int length = fCurrentEntity.position - offset; buffer.append(fCurrentEntity.ch, offset, length); return true; } } int length = fCurrentEntity.position - offset; if (done) { length -= delimLen; } buffer.append (fCurrentEntity.ch, offset, length); // return true if string was skipped } while (!done); return !done; } // Adapted from: // org.apache.xerces.impl.XMLEntityManager.EntityScanner.skipChar /** * Skips a character appearing immediately on the input. *

* Note: The character is consumed only if it matches * the specified character. * * @param c The character to skip. * * @return Returns true if the character was skipped. * * @throws IOException Thrown if i/o error occurs. * @throws EOFException Thrown on end of file. */ public boolean skipChar(int c) throws IOException { // load more characters, if needed if (fCurrentEntity.position == fCurrentEntity.count) { load(0, true); } // skip character int cc = fCurrentEntity.ch[fCurrentEntity.position]; if (cc == c) { fCurrentEntity.position++; return true; } else if (c == '\n' && cc == '\r' && fCurrentEntity.isExternal()) { // handle newlines if (fCurrentEntity.position == fCurrentEntity.count) { fCurrentEntity.ch[0] = (char)cc; load(1, false); } fCurrentEntity.position++; if (fCurrentEntity.ch[fCurrentEntity.position] == '\n') { fCurrentEntity.position++; } return true; } // character was not skipped return false; } // Adapted from: // org.apache.xerces.impl.XMLEntityManager.EntityScanner.skipSpaces /** * Skips space characters appearing immediately on the input. *

* Note: The characters are consumed only if they are * space characters. * * @return Returns true if at least one space character was skipped. * * @throws IOException Thrown if i/o error occurs. * @throws EOFException Thrown on end of file. * * @see XMLChar#isSpace */ public boolean skipSpaces() throws IOException { // load more characters, if needed if (fCurrentEntity.position == fCurrentEntity.count) { load(0, true); } // skip spaces int c = fCurrentEntity.ch[fCurrentEntity.position]; if (XMLChar.isSpace(c)) { boolean external = fCurrentEntity.isExternal(); do { boolean entityChanged = false; // handle newlines if (c == '\n' || (external && c == '\r')) { if (fCurrentEntity.position == fCurrentEntity.count - 1) { fCurrentEntity.ch[0] = (char)c; entityChanged = load(1, true); if (!entityChanged) // the load change the position to be 1, // need to restore it when entity not changed fCurrentEntity.position = 0; } if (c == '\r' && external) { // REVISIT: Does this need to be updated to fix the // #x0D ^#x0A newline normalization problem? -Ac if (fCurrentEntity.ch[++fCurrentEntity.position] != '\n') { fCurrentEntity.position--; } } /*** NEWLINE NORMALIZATION *** else { if (fCurrentEntity.ch[fCurrentEntity.position + 1] == '\r' && external) { fCurrentEntity.position++; } } /***/ } // load more characters, if needed if (!entityChanged) fCurrentEntity.position++; if (fCurrentEntity.position == fCurrentEntity.count) { load(0, true); } } while (XMLChar.isSpace(c = fCurrentEntity.ch[fCurrentEntity.position])); return true; } // no spaces were found return false; } /** * Skips the specified string appearing immediately on the input. *

* Note: The characters are consumed only if they are * space characters. * * @param s The string to skip. * * @return Returns true if the string was skipped. * * @throws IOException Thrown if i/o error occurs. * @throws EOFException Thrown on end of file. */ public boolean skipString(String s) throws IOException { // load more characters, if needed if (fCurrentEntity.position == fCurrentEntity.count) { load(0, true); } // skip string final int length = s.length(); for (int i = 0; i < length; i++) { char c = fCurrentEntity.ch[fCurrentEntity.position++]; if (c != s.charAt(i)) { fCurrentEntity.position -= i + 1; return false; } if (i < length - 1 && fCurrentEntity.position == fCurrentEntity.count) { System.arraycopy(fCurrentEntity.ch, fCurrentEntity.count - i - 1, fCurrentEntity.ch, 0, i + 1); // REVISIT: Can a string to be skipped cross an // entity boundary? -Ac if (load(i + 1, false)) { fCurrentEntity.position -= i + 1; return false; } } } return true; } // Adapted from: // org.apache.xerces.impl.XMLEntityManager.EntityScanner.load /** * Loads a chunk of text. * * @param offset The offset into the character buffer to * read the next batch of characters. * @param changeEntity True if the load should change entities * at the end of the entity, otherwise leave * the current entity in place and the entity * boundary will be signaled by the return * value. * * @return Returns true if the entity changed as a result of this * load operation. */ final boolean load(int offset, boolean changeEntity) throws IOException { // read characters int count = fCurrentEntity.reader.read(fCurrentEntity.ch, offset, DEFAULT_XMLDECL_BUFFER_SIZE); // reset count and position boolean entityChanged = false; if (count != -1) { if (count != 0) { fCurrentEntity.count = count + offset; fCurrentEntity.position = offset; } } // end of this entity else { fCurrentEntity.count = offset; fCurrentEntity.position = offset; entityChanged = true; if (changeEntity) { endEntity(); if (fCurrentEntity == null) { throw new EOFException(); } // handle the trailing edges if (fCurrentEntity.position == fCurrentEntity.count) { load(0, false); } } } return entityChanged; } // Adapted from: // org.apache.xerces.impl.XMLEntityManager.RewindableInputStream /** * This class wraps the byte inputstreams we're presented with. * We need it because java.io.InputStreams don't provide * functionality to reread processed bytes, and they have a habit * of reading more than one character when you call their read() * methods. This means that, once we discover the true (declared) * encoding of a document, we can neither backtrack to read the * whole doc again nor start reading where we are with a new * reader. * * This class allows rewinding an inputStream by allowing a mark * to be set, and the stream reset to that position. The * class assumes that it needs to read one character per * invocation when it's read() method is invoked, but uses the * underlying InputStream's read(char[], offset length) method--it * won't buffer data read this way! * * @author Neil Graham, IBM * @author Glenn Marcy, IBM */ private final class RewindableInputStream extends InputStream { private InputStream fInputStream; private byte[] fData; private int fEndOffset; private int fOffset; private int fLength; private int fMark; public RewindableInputStream(InputStream is) { fData = new byte[DEFAULT_XMLDECL_BUFFER_SIZE]; fInputStream = is; fEndOffset = -1; fOffset = 0; fLength = 0; fMark = 0; } @Override public int read() throws IOException { int b = 0; if (fOffset < fLength) { return fData[fOffset++] & 0xff; } if (fOffset == fEndOffset) { return -1; } if (fOffset == fData.length) { byte[] newData = new byte[fOffset << 1]; System.arraycopy(fData, 0, newData, 0, fOffset); fData = newData; } b = fInputStream.read(); if (b == -1) { fEndOffset = fOffset; return -1; } fData[fLength++] = (byte)b; fOffset++; return b & 0xff; } @Override public int read(byte[] b, int off, int len) throws IOException { int bytesLeft = fLength - fOffset; if (bytesLeft == 0) { if (fOffset == fEndOffset) { return -1; } // better get some more for the voracious reader... int returnedVal = read(); if (returnedVal == -1) { fEndOffset = fOffset; return -1; } b[off] = (byte)returnedVal; return 1; } if (len < bytesLeft) { if (len <= 0) { return 0; } } else { len = bytesLeft; } if (b != null) { System.arraycopy(fData, fOffset, b, off, len); } fOffset += len; return len; } @Override public long skip(long n) throws IOException { int bytesLeft; if (n <= 0) { return 0; } bytesLeft = fLength - fOffset; if (bytesLeft == 0) { if (fOffset == fEndOffset) { return 0; } return fInputStream.skip(n); } if (n <= bytesLeft) { fOffset += n; return n; } fOffset += bytesLeft; if (fOffset == fEndOffset) { return bytesLeft; } n -= bytesLeft; /* * In a manner of speaking, when this class isn't permitting more * than one byte at a time to be read, it is "blocking". The * available() method should indicate how much can be read without * blocking, so while we're in this mode, it should only indicate * that bytes in its buffer are available; otherwise, the result of * available() on the underlying InputStream is appropriate. */ return fInputStream.skip(n) + bytesLeft; } @Override public int available() throws IOException { int bytesLeft = fLength - fOffset; if (bytesLeft == 0) { if (fOffset == fEndOffset) { return -1; } return 0; } return bytesLeft; } @Override public synchronized void mark(int howMuch) { fMark = fOffset; } @Override public synchronized void reset() { fOffset = fMark; } @Override public boolean markSupported() { return true; } @Override public void close() throws IOException { if (fInputStream != null) { fInputStream.close(); fInputStream = null; } } } // end of RewindableInputStream class // Adapted from: // org.apache.xerces.impl.XMLDocumentScannerImpl.dispatch private void scanXMLDecl() throws IOException, JasperException { if (skipString(" *

     * [23] XMLDecl ::= '<?xml' VersionInfo EncodingDecl? SDDecl? S? '?>'
     * [24] VersionInfo ::= S 'version' Eq (' VersionNum ' | " VersionNum ")
     * [80] EncodingDecl ::= S 'encoding' Eq ('"' EncName '"' |  "'" EncName "'" )
     * [81] EncName ::= [A-Za-z] ([A-Za-z0-9._] | '-')*
     * [32] SDDecl ::= S 'standalone' Eq (("'" ('yes' | 'no') "'")
     *                 | ('"' ('yes' | 'no') '"'))
     *
     * [77] TextDecl ::= '<?xml' VersionInfo? EncodingDecl S? '?>'
     * 
* * @param scanningTextDecl True if a text declaration is to * be scanned instead of an XML * declaration. */ private void scanXMLDeclOrTextDecl(boolean scanningTextDecl) throws IOException, JasperException { // scan decl scanXMLDeclOrTextDecl(scanningTextDecl, fStrings); // pseudo-attribute values String encodingPseudoAttr = fStrings[1]; // set encoding on reader if (encodingPseudoAttr != null) { isEncodingSetInProlog = true; encoding = encodingPseudoAttr; } } // Adapted from: // org.apache.xerces.impl.XMLScanner.scanXMLDeclOrTextDecl /** * Scans an XML or text declaration. *

*

     * [23] XMLDecl ::= ''
     * [24] VersionInfo ::= S 'version' Eq (' VersionNum ' | " VersionNum ")
     * [80] EncodingDecl ::= S 'encoding' Eq ('"' EncName '"' |  "'" EncName "'" )
     * [81] EncName ::= [A-Za-z] ([A-Za-z0-9._] | '-')*
     * [32] SDDecl ::= S 'standalone' Eq (("'" ('yes' | 'no') "'")
     *                 | ('"' ('yes' | 'no') '"'))
     *
     * [77] TextDecl ::= ''
     * 
* * @param scanningTextDecl True if a text declaration is to * be scanned instead of an XML * declaration. * @param pseudoAttributeValues An array of size 3 to return the version, * encoding and standalone pseudo attribute values * (in that order). * * Note: This method uses fString, anything in it * at the time of calling is lost. */ private void scanXMLDeclOrTextDecl(boolean scanningTextDecl, String[] pseudoAttributeValues) throws IOException, JasperException { // pseudo-attribute values String version = null; String encoding = null; String standalone = null; // scan pseudo-attributes final int STATE_VERSION = 0; final int STATE_ENCODING = 1; final int STATE_STANDALONE = 2; final int STATE_DONE = 3; int state = STATE_VERSION; boolean dataFoundForTarget = false; boolean sawSpace = skipSpaces(); while (peekChar() != '?') { dataFoundForTarget = true; String name = scanPseudoAttribute(scanningTextDecl, fString); switch (state) { case STATE_VERSION: { if (name == fVersionSymbol) { if (!sawSpace) { if (scanningTextDecl) { MESSAGES.requiredSpaceBeforeVersionInTextDeclaration(); } else { MESSAGES.requiredSpaceBeforeVersionInXmlDeclaration(); } } version = fString.toString(); state = STATE_ENCODING; if (!version.equals("1.0")) { // REVISIT: XML REC says we should throw an error // in such cases. // some may object the throwing of fatalError. err.jspError(MESSAGES.unsupportedXmlVersion(version)); } } else if (name == fEncodingSymbol) { if (!scanningTextDecl) { err.jspError(MESSAGES.noXmlVersion()); } if (!sawSpace) { if (scanningTextDecl) { MESSAGES.requiredSpaceBeforeEncodingInTextDeclaration(); } else { MESSAGES.requiredSpaceBeforeEncodingInXmlDeclaration(); } } encoding = fString.toString(); state = scanningTextDecl ? STATE_DONE : STATE_STANDALONE; } else { if (scanningTextDecl) { err.jspError(MESSAGES.requiredEncodingDeclaration()); } else { err.jspError(MESSAGES.requiredVersionDeclaration()); } } break; } case STATE_ENCODING: { if (name == fEncodingSymbol) { if (!sawSpace) { if (scanningTextDecl) { err.jspError(MESSAGES.requiredSpaceBeforeEncodingInTextDeclaration()); } else { err.jspError(MESSAGES.requiredSpaceBeforeEncodingInXmlDeclaration()); } } encoding = fString.toString(); state = scanningTextDecl ? STATE_DONE : STATE_STANDALONE; // TODO: check encoding name; set encoding on // entity scanner } else if (!scanningTextDecl && name == fStandaloneSymbol) { if (!sawSpace) { err.jspError(MESSAGES.requiredSpaceBeforeStandaloneInXmlDeclaration()); } standalone = fString.toString(); state = STATE_DONE; if (!standalone.equals("yes") && !standalone.equals("no")) { err.jspError(MESSAGES.invalidStandaloneDeclaration(standalone)); } } else { err.jspError(MESSAGES.requiredEncodingDeclaration()); } break; } case STATE_STANDALONE: { if (name == fStandaloneSymbol) { if (!sawSpace) { err.jspError(MESSAGES.requiredSpaceBeforeStandaloneInXmlDeclaration()); } standalone = fString.toString(); state = STATE_DONE; if (!standalone.equals("yes") && !standalone.equals("no")) { err.jspError(MESSAGES.invalidStandaloneDeclaration(standalone)); } } else { err.jspError(MESSAGES.requiredEncodingDeclaration()); } break; } default: { err.jspError(MESSAGES.invalidPseudoAttribute()); } } sawSpace = skipSpaces(); } // REVISIT: should we remove this error reporting? if (scanningTextDecl && state != STATE_DONE) { err.jspError(MESSAGES.missingPseudoAttribute()); } // If there is no data in the xml or text decl then we fail to report // error for version or encoding info above. if (scanningTextDecl) { if (!dataFoundForTarget && encoding == null) { err.jspError(MESSAGES.requiredEncodingDeclaration()); } } else { if (!dataFoundForTarget && version == null) { err.jspError(MESSAGES.requiredVersionDeclaration()); } } // end if (!skipChar('?')) { err.jspError(MESSAGES.malformedXmlDeclaration()); } if (!skipChar('>')) { err.jspError(MESSAGES.malformedXmlDeclaration()); } // fill in return array pseudoAttributeValues[0] = version; pseudoAttributeValues[1] = encoding; pseudoAttributeValues[2] = standalone; } // Adapted from: // org.apache.xerces.impl.XMLScanner.scanPseudoAttribute /** * Scans a pseudo attribute. * * @param scanningTextDecl True if scanning this pseudo-attribute for a * TextDecl; false if scanning XMLDecl. This * flag is needed to report the correct type of * error. * @param value The string to fill in with the attribute * value. * * @return The name of the attribute * * Note: This method uses fStringBuffer2, anything in it * at the time of calling is lost. */ public String scanPseudoAttribute(boolean scanningTextDecl, XMLString value) throws IOException, JasperException { String name = scanName(); if (name == null) { err.jspError(MESSAGES.missingPseudoAttributeName()); } skipSpaces(); if (!skipChar('=')) { if (scanningTextDecl) { err.jspError(MESSAGES.missingEqualsInTextDeclaration(name)); } else { err.jspError(MESSAGES.missingEqualsInXmlDeclaration(name)); } } skipSpaces(); int quote = peekChar(); if (quote != '\'' && quote != '"') { if (scanningTextDecl) { err.jspError(MESSAGES.missingQuoteInTextDeclaration(name)); } else { err.jspError(MESSAGES.missingQuoteInXmlDeclaration(name)); } } scanChar(); int c = scanLiteral(quote, value); if (c != quote) { fStringBuffer2.clear(); do { fStringBuffer2.append(value); if (c != -1) { if (c == '&' || c == '%' || c == '<' || c == ']') { fStringBuffer2.append((char)scanChar()); } else if (XMLChar.isHighSurrogate(c)) { scanSurrogates(fStringBuffer2); } else if (XMLChar.isInvalid(c)) { if (scanningTextDecl) { err.jspError(MESSAGES.invalidCharInTextDeclaration(Integer.toString(c, 16))); } else { err.jspError(MESSAGES.invalidCharInXmlDeclaration(Integer.toString(c, 16))); } scanChar(); } } c = scanLiteral(quote, value); } while (c != quote); fStringBuffer2.append(value); value.setValues(fStringBuffer2); } if (!skipChar(quote)) { if (scanningTextDecl) { err.jspError(MESSAGES.missingClosingQuoteInTextDeclaration(name)); } else { err.jspError(MESSAGES.missingClosingQuoteInXmlDeclaration(name)); } } // return return name; } // Adapted from: // org.apache.xerces.impl.XMLScanner.scanPIData /** * Scans a processing data. This is needed to handle the situation * where a document starts with a processing instruction whose * target name starts with "xml". (e.g. xmlfoo) * * Note: This method uses fStringBuffer, anything in it * at the time of calling is lost. * * @param target The PI target * @param data The string to fill in with the data */ private void scanPIData(String target, XMLString data) throws IOException, JasperException { // check target if (target.length() == 3) { char c0 = Character.toLowerCase(target.charAt(0)); char c1 = Character.toLowerCase(target.charAt(1)); char c2 = Character.toLowerCase(target.charAt(2)); if (c0 == 'x' && c1 == 'm' && c2 == 'l') { err.jspError(MESSAGES.reservedPiTarget()); } } // spaces if (!skipSpaces()) { if (skipString("?>")) { // we found the end, there is no data data.clear(); return; } else { // if there is data there should be some space err.jspError(MESSAGES.requiredWhiteSpaceAfterPiTarget()); } } fStringBuffer.clear(); // data if (scanData("?>", fStringBuffer)) { do { int c = peekChar(); if (c != -1) { if (XMLChar.isHighSurrogate(c)) { scanSurrogates(fStringBuffer); } else if (XMLChar.isInvalid(c)) { err.jspError(MESSAGES.invalidCharInProcessingInstruction(Integer.toHexString(c))); scanChar(); } } } while (scanData("?>", fStringBuffer)); } data.setValues(fStringBuffer); } // Adapted from: // org.apache.xerces.impl.XMLScanner.scanSurrogates /** * Scans surrogates and append them to the specified buffer. *

* Note: This assumes the current char has already been * identified as a high surrogate. * * @param buf The StringBuffer to append the read surrogates to. * @return True if it succeeded. */ private boolean scanSurrogates(XMLStringBuffer buf) throws IOException, JasperException { int high = scanChar(); int low = peekChar(); if (!XMLChar.isLowSurrogate(low)) { err.jspError(MESSAGES.invalidCharInContent(Integer.toString(high, 16))); return false; } scanChar(); // convert surrogates to supplemental character int c = XMLChar.supplemental((char)high, (char)low); // supplemental character must be a valid XML character if (!XMLChar.isValid(c)) { err.jspError(MESSAGES.invalidCharInContent(Integer.toString(c, 16))); return false; } // fill in the buffer buf.append((char)high); buf.append((char)low); return true; } // Adapted from: // org.apache.xerces.impl.XMLScanner.reportFatalError /** * Convenience function used in all XML scanners. */ private void reportFatalError(String msgId, String arg) throws JasperException { err.jspError(msgId, arg); } }





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