/* Woodstox XML processor
*
* Copyright (c) 2004- Tatu Saloranta, tatu.saloranta@iki.fi
*
* Licensed under the License specified in file LICENSE, included with
* the source code.
* You may not use this file except in compliance with the License.
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.ctc.wstx.io;
import java.io.*;
import java.text.MessageFormat;
import javax.xml.stream.Location;
import javax.xml.stream.XMLReporter;
import javax.xml.stream.XMLStreamException;
import org.codehaus.stax2.validation.XMLValidationProblem;
import com.ctc.wstx.api.ReaderConfig;
import com.ctc.wstx.cfg.ErrorConsts;
import com.ctc.wstx.cfg.ParsingErrorMsgs;
import com.ctc.wstx.exc.*;
import com.ctc.wstx.util.StringUtil;
/**
* Input bootstrap class used when input comes from a Reader; in this case,
* encoding is already known, and thus encoding from XML declaration (if
* any) is only double-checked, not really used.
*<p>
* Note: since the actual Reader to use after bootstrapping is pre-constructed,
* the local input buffer can (and should) be quite small.
*/
public final class ReaderBootstrapper
extends InputBootstrapper
{
final static char CHAR_BOM_MARKER = (char) 0xFEFF;
/*
////////////////////////////////////////
// Configuration
////////////////////////////////////////
*/
/**
* Underlying Reader to use for reading content.
*/
final Reader mIn;
/**
* Encoding identifier processing application passed in; if not null,
* will be compared to actual xml declaration based encoding (if
* declaration found)
*/
final String mInputEncoding;
/*
///////////////////////////////////////////////////////////////
// Input buffering
///////////////////////////////////////////////////////////////
*/
private char[] mCharBuffer;
private int mInputPtr;
private int mInputLen;
/*
////////////////////////////////////////
// Life-cycle
////////////////////////////////////////
*/
private ReaderBootstrapper(String pubId, String sysId, Reader r, String appEncoding)
{
super(pubId, sysId);
mIn = r;
if (appEncoding == null) { // may still be able to figure it out
if (r instanceof InputStreamReader) {
appEncoding = ((InputStreamReader) r).getEncoding();
}
}
mInputEncoding = appEncoding;
}
/*
////////////////////////////////////////
// Public API
////////////////////////////////////////
*/
/**
* @param r Eventual reader that will be reading actual content, after
* bootstrapping finishes
* @param appEncoding Encoding that application declared; may be null.
* If not null, will be compared to actual declaration found; and
* incompatibility reported as a potential (but not necessarily fatal)
* problem.
*/
public static ReaderBootstrapper getInstance(String pubId, String sysId,
Reader r, String appEncoding)
{
return new ReaderBootstrapper(pubId, sysId, r, appEncoding);
}
/**
* Method called to do actual bootstrapping.
*
* @return Actual reader to use for reading xml content
*/
public Reader bootstrapInput(ReaderConfig cfg, boolean mainDoc, int xmlVersion)
throws IOException, XMLStreamException
{
/* First order of business: allocate input buffer. Not done during
* construction for simplicity; that way config object need not be
* passed before actual bootstrap method is called
*/
/* Let's make sure buffer is at least 6 chars (to know '<?xml '
* prefix), and preferably big enough to contain the whole declaration,
* but not too long to waste space -- it won't be reused
* by the real input reader.
*/
mCharBuffer = (cfg == null) ? new char[128] : cfg.allocSmallCBuffer(128); // 128 chars should be enough
initialLoad(7);
/* Only need 6 for signature ("<?xml\s"), but there may be a leading
* BOM in there... and a valid xml declaration has to be longer
* than 7 chars anyway (although, granted, shortest valid xml docl
* is just 4 chars... "<a/>")
*/
if (mInputLen >= 7) {
char c = mCharBuffer[mInputPtr];
// BOM to skip?
if (c == CHAR_BOM_MARKER) {
c = mCharBuffer[++mInputPtr];
}
if (c == '<') {
if (mCharBuffer[mInputPtr+1] == '?'
&& mCharBuffer[mInputPtr+2] == 'x'
&& mCharBuffer[mInputPtr+3] == 'm'
&& mCharBuffer[mInputPtr+4] == 'l'
&& mCharBuffer[mInputPtr+5] <= CHAR_SPACE) {
// Yup, got the declaration ok!
mInputPtr += 6; // skip declaration
readXmlDecl(mainDoc, xmlVersion);
if (mFoundEncoding != null && mInputEncoding != null) {
verifyXmlEncoding(cfg);
}
}
} else {
/* We may also get something that would be invalid xml
* ("garbage" char; neither '<' nor space). If so, and
* it's one of "well-known" cases, we can not only throw
* an exception but also indicate a clue as to what is likely
* to be wrong.
*/
/* Specifically, UTF-8 read via, say, ISO-8859-1 reader, can
* "leak" marker (0xEF, 0xBB, 0xBF). While we could just eat
* it, there's bound to be other problems cropping up, so let's
* inform about the problem right away.
*/
if (c == 0xEF) {
throw new WstxIOException("Unexpected first character (char code 0xEF), not valid in xml document: could be mangled UTF-8 BOM marker. Make sure that the Reader uses correct encoding or pass an InputStream instead");
}
}
}
/* Ok, now; do we have unused chars we have read that need to
* be merged in?
*/
if (mInputPtr < mInputLen) {
return new MergedReader(cfg, mIn, mCharBuffer, mInputPtr, mInputLen);
}
return mIn;
}
public String getInputEncoding() {
return mInputEncoding;
}
public int getInputTotal() {
return mInputProcessed + mInputPtr;
}
public int getInputColumn() {
return (mInputPtr - mInputRowStart);
}
/*
////////////////////////////////////////
// Internal methods, parsing
////////////////////////////////////////
*/
protected void verifyXmlEncoding(ReaderConfig cfg)
throws XMLStreamException
{
String inputEnc = mInputEncoding;
// Close enough?
if (StringUtil.equalEncodings(inputEnc, mFoundEncoding)) {
return;
}
/* Ok, maybe the difference is just with endianness indicator?
* (UTF-16BE vs. UTF-16)?
*/
// !!! TBI
XMLReporter rep = cfg.getXMLReporter();
if (rep != null) {
Location loc = getLocation();
String msg = MessageFormat.format(ErrorConsts.W_MIXED_ENCODINGS,
new Object[] { mFoundEncoding,
inputEnc });
String type = ErrorConsts.WT_XML_DECL;
/* 30-May-2008, tatus: Should wrap all the info as XMValidationProblem
* since that's Woodstox' contract wrt. relatedInformation field.
*/
XMLValidationProblem prob = new XMLValidationProblem(loc, msg, XMLValidationProblem.SEVERITY_WARNING, type);
rep.report(msg, type, prob, loc);
}
}
/*
/////////////////////////////////////////////////////
// Internal methods, loading input data
/////////////////////////////////////////////////////
*/
protected boolean initialLoad(int minimum)
throws IOException
{
mInputPtr = 0;
mInputLen = 0;
while (mInputLen < minimum) {
int count = mIn.read(mCharBuffer, mInputLen,
mCharBuffer.length - mInputLen);
if (count < 1) {
return false;
}
mInputLen += count;
}
return true;
}
protected void loadMore()
throws IOException, WstxException
{
/* Need to make sure offsets are properly updated for error
* reporting purposes, and do this now while previous amounts
* are still known.
*/
mInputProcessed += mInputLen;
mInputRowStart -= mInputLen;
mInputPtr = 0;
mInputLen = mIn.read(mCharBuffer, 0, mCharBuffer.length);
if (mInputLen < 1) {
throw new WstxEOFException(ParsingErrorMsgs.SUFFIX_IN_XML_DECL,
getLocation());
}
}
/*
/////////////////////////////////////////////////////
// Implementations of abstract parsing methods
/////////////////////////////////////////////////////
*/
protected void pushback() {
--mInputPtr;
}
protected int getNext()
throws IOException, WstxException
{
return (mInputPtr < mInputLen) ?
mCharBuffer[mInputPtr++] : nextChar();
}
protected int getNextAfterWs(boolean reqWs)
throws IOException, WstxException
{
int count = 0;
while (true) {
char c = (mInputPtr < mInputLen) ?
mCharBuffer[mInputPtr++] : nextChar();
if (c > CHAR_SPACE) {
if (reqWs && count == 0) {
reportUnexpectedChar(c, ERR_XMLDECL_EXP_SPACE);
}
return c;
}
if (c == CHAR_CR || c == CHAR_LF) {
skipCRLF(c);
} else if (c == CHAR_NULL) {
reportNull();
}
++count;
}
}
/**
* @return First character that does not match expected, if any;
* CHAR_NULL if match succeeded
*/
protected int checkKeyword(String exp)
throws IOException, WstxException
{
int len = exp.length();
for (int ptr = 1; ptr < len; ++ptr) {
char c = (mInputPtr < mInputLen) ?
mCharBuffer[mInputPtr++] : nextChar();
if (c != exp.charAt(ptr)) {
return c;
}
if (c == CHAR_NULL) {
reportNull();
}
}
return CHAR_NULL;
}
protected int readQuotedValue(char[] kw, int quoteChar)
throws IOException, WstxException
{
int i = 0;
int len = kw.length;
while (true) {
char c = (mInputPtr < mInputLen) ?
mCharBuffer[mInputPtr++] : nextChar();
if (c == CHAR_CR || c == CHAR_LF) {
skipCRLF(c);
} else if (c == CHAR_NULL) {
reportNull();
}
if (c == quoteChar) {
return (i < len) ? i : -1;
}
// Let's just truncate longer values, but match quote
if (i < len) {
kw[i++] = c;
}
}
}
protected Location getLocation()
{
return new WstxInputLocation(null, mPublicId, mSystemId,
mInputProcessed + mInputPtr - 1,
mInputRow, mInputPtr - mInputRowStart);
}
/*
/////////////////////////////////////////////////////
// Internal methods, single-byte access methods
/////////////////////////////////////////////////////
*/
protected char nextChar()
throws IOException, WstxException
{
if (mInputPtr >= mInputLen) {
loadMore();
}
return mCharBuffer[mInputPtr++];
}
protected void skipCRLF(char lf)
throws IOException, WstxException
{
if (lf == CHAR_CR) {
char c = (mInputPtr < mInputLen) ?
mCharBuffer[mInputPtr++] : nextChar();
if (c != BYTE_LF) {
--mInputPtr; // pushback if not 2-char/byte lf
}
}
++mInputRow;
mInputRowStart = mInputPtr;
}
}