/* Aalto XML processor
*
* Copyright (c) 2006- Tatu Saloranta, tatu.saloranta@iki.fi
*
* Licensed under the License specified in the file LICENSE which is
* 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.fasterxml.aalto.in;
import java.io.*;
import javax.xml.stream.Location;
import javax.xml.stream.XMLStreamException;
import com.fasterxml.aalto.IoStreamException;
import com.fasterxml.aalto.WFCException;
import com.fasterxml.aalto.XmlConsts;
/**
* Abstract base class that defines shared functionality between different
* bootstrappers (byte stream, char Readers, block input)
*/
public abstract class InputBootstrapper
implements XmlConsts
{
/*
////////////////////////////////////////////////////////////
// Shared string consts
////////////////////////////////////////////////////////////
*/
protected final static String ERR_XMLDECL_KW_VERSION = "; expected keyword '"+XmlConsts.XML_DECL_KW_VERSION+"'";
protected final static String ERR_XMLDECL_KW_ENCODING = "; expected keyword '"+XmlConsts.XML_DECL_KW_ENCODING+"'";
protected final static String ERR_XMLDECL_KW_STANDALONE = "; expected keyword '"+XmlConsts.XML_DECL_KW_STANDALONE+"'";
protected final static String ERR_XMLDECL_END_MARKER = "; expected \"?>\" end marker";
protected final static String ERR_XMLDECL_EXP_SPACE = "; expected a white space";
protected final static String ERR_XMLDECL_EXP_EQ = "; expected '=' after ";
protected final static String ERR_XMLDECL_EXP_ATTRVAL = "; expected a quote character enclosing value for ";
/*
////////////////////////////////////////////////////////////
// Input location data
////////////////////////////////////////////////////////////
*/
/**
* Current number of input units (bytes or chars) that were processed in
* previous blocks,
* before contents of current input buffer.
*<p>
* Note: includes possible BOMs, if those were part of the input.
*/
protected int _inputProcessed = 0;
/**
* Current row location of current point in input buffer, using
* zero-based counting.
*/
protected int _inputRow = 0;
/**
* Current index of the first character of the current row in input
* buffer. Needed to calculate column position, if necessary; benefit
* of not having column itself is that this only has to be updated
* once per line.
*/
protected int _inputRowStart = 0;
/*
////////////////////////////////////////
// Info passed by the caller
////////////////////////////////////////
*/
final ReaderConfig _config;
/*
////////////////////////////////////////
// Info from XML declaration
////////////////////////////////////////
*/
//boolean mHadDeclaration = false;
/**
* XML declaration from the input (1.0, 1.1 or 'unknown')
*/
int mDeclaredXmlVersion = XmlConsts.XML_V_UNKNOWN;
/**
* Value of encoding pseudo-attribute from xml declaration, if
* one was found; null otherwise.
*/
String mFoundEncoding;
String mStandalone;
/*
////////////////////////////////////////
// Temporary data
////////////////////////////////////////
*/
/**
* Need a short buffer to read in values of pseudo-attributes (version,
* encoding, standalone). Don't really need tons of space; just enough
* for the longest anticipated encoding id... and maybe few chars just
* in case (for additional white space that we ignore)
*/
final char[] mKeyword;
/*
////////////////////////////////////////
// Life-cycle
////////////////////////////////////////
*/
protected InputBootstrapper(ReaderConfig cfg)
{
_config = cfg;
mKeyword = cfg.allocSmallCBuffer(ReaderConfig.DEFAULT_SMALL_BUFFER_LEN);
}
/**
* Main bootstrapping method, which will try to open the underlying
* input source, check its encoding, read xml declaration if
* there is one, and finally create a scanner for actual parsing.
*/
public final XmlScanner bootstrap()
throws XMLStreamException
{
try {
return doBootstrap();
} catch (IOException ioe) {
throw new IoStreamException(ioe);
} finally {
_config.freeSmallCBuffer(mKeyword);
}
}
public abstract XmlScanner doBootstrap()
throws IOException, XMLStreamException;
/*
////////////////////////////////////////
// Package methods, parsing
////////////////////////////////////////
*/
/**
* Method that will parse xml declaration, which at this point is
* known to exist.
*/
protected void readXmlDeclaration()
throws IOException, XMLStreamException
{
int c = getNextAfterWs(false);
// First, version pseudo-attribute:
if (c != 'v') {
reportUnexpectedChar(c, ERR_XMLDECL_KW_VERSION);
} else { // ok, should be version
mDeclaredXmlVersion = readXmlVersion();
c = getWsOrChar('?');
}
// Then, 'encoding'
if (c == 'e') {
mFoundEncoding = readXmlEncoding();
c = getWsOrChar('?');
}
// Then, 'standalone' (for main doc)
if (c == 's') {
mStandalone = readXmlStandalone();
c = getWsOrChar('?');
}
// And finally, need to have closing markers
if (c != '?') {
reportUnexpectedChar(c, ERR_XMLDECL_END_MARKER);
}
c = getNext();
if (c != '>') {
reportUnexpectedChar(c, ERR_XMLDECL_END_MARKER);
}
}
/**
* @return Xml version declaration read
*/
private final int readXmlVersion()
throws IOException, XMLStreamException
{
int c = checkKeyword(XmlConsts.XML_DECL_KW_VERSION);
if (c != CHAR_NULL) {
reportUnexpectedChar(c, XmlConsts.XML_DECL_KW_VERSION);
}
c = handleEq(XmlConsts.XML_DECL_KW_VERSION);
int len = readQuotedValue(mKeyword, c);
if (len == 3) {
if (mKeyword[0] == '1' && mKeyword[1] == '.') {
c = mKeyword[2];
if (c == '0') {
return XmlConsts.XML_V_10;
}
if (c == '1') {
return XmlConsts.XML_V_11;
}
}
}
// Nope; error. -1 indicates run off...
String got;
if (len < 0) {
got = "'"+new String(mKeyword)+"[..]'";
} else if (len == 0) {
got = "<empty>";
} else {
got = "'"+new String(mKeyword, 0, len)+"'";
}
reportPseudoAttrProblem(XmlConsts.XML_DECL_KW_VERSION, got,
XmlConsts.XML_V_10_STR, XmlConsts.XML_V_11_STR);
return XmlConsts.XML_V_UNKNOWN; // never gets here, but compiler needs it
}
private final String readXmlEncoding()
throws IOException, XMLStreamException
{
int c = checkKeyword(XmlConsts.XML_DECL_KW_ENCODING);
if (c != CHAR_NULL) {
reportUnexpectedChar(c, XmlConsts.XML_DECL_KW_ENCODING);
}
c = handleEq(XmlConsts.XML_DECL_KW_ENCODING);
int len = readQuotedValue(mKeyword, c);
/* Hmmh. How about "too long" encodings? Maybe just truncate them,
* for now?
*/
if (len == 0) { // let's still detect missing value...
reportPseudoAttrProblem(XmlConsts.XML_DECL_KW_ENCODING, null,
null, null);
}
if (len < 0) { // will be truncated...
return new String(mKeyword);
}
return new String(mKeyword, 0, len);
}
private final String readXmlStandalone()
throws IOException, XMLStreamException
{
int c = checkKeyword(XmlConsts.XML_DECL_KW_STANDALONE);
if (c != CHAR_NULL) {
reportUnexpectedChar(c, XmlConsts.XML_DECL_KW_STANDALONE);
}
c = handleEq(XmlConsts.XML_DECL_KW_STANDALONE);
int len = readQuotedValue(mKeyword, c);
if (len == 2) {
if (mKeyword[0] == 'n' && mKeyword[1] == 'o') {
return XmlConsts.XML_SA_NO;
}
} else if (len == 3) {
if (mKeyword[0] == 'y' && mKeyword[1] == 'e'
&& mKeyword[2] == 's') {
return XmlConsts.XML_SA_YES;
}
}
// Nope; error. -1 indicates run off...
String got;
if (len < 0) {
got = "'"+new String(mKeyword)+"[..]'";
} else if (len == 0) {
got = "<empty>";
} else {
got = "'"+new String(mKeyword, 0, len)+"'";
}
reportPseudoAttrProblem(XmlConsts.XML_DECL_KW_STANDALONE, got,
XmlConsts.XML_SA_YES, XmlConsts.XML_SA_NO);
return got; // never gets here, but compiler can't figure it out
}
private final int handleEq(String attr)
throws IOException, XMLStreamException
{
int c = getNextAfterWs(false);
if (c != '=') {
reportUnexpectedChar(c, ERR_XMLDECL_EXP_EQ+"'"+attr+"'");
}
c = getNextAfterWs(false);
if (c != '"' && c != '\'') {
reportUnexpectedChar(c, ERR_XMLDECL_EXP_ATTRVAL+"'"+attr+"'");
}
return c;
}
/**
* Method that should get next character, which has to be either specified
* character (usually end marker), OR, any character as long as there'
* at least one space character before it.
*/
private final int getWsOrChar(int ok)
throws IOException, XMLStreamException
{
int c = getNext();
if (c == ok) {
return c;
}
if (c > XmlConsts.CHAR_SPACE) {
reportUnexpectedChar(c, "; expected either '"+((char) ok)+"' or white space");
}
if (c == XmlConsts.CHAR_LF || c == XmlConsts.CHAR_CR) {
// Need to push it back to be processed properly
pushback();
}
return getNextAfterWs(false);
}
/*
////////////////////////////////////////////////////////
// Abstract parsing methods for sub-classes to implement
////////////////////////////////////////////////////////
*/
protected abstract void pushback();
protected abstract int getNext()
throws IOException, XMLStreamException;
protected abstract int getNextAfterWs(boolean reqWs)
throws IOException, XMLStreamException;
/**
* @return First character that does not match expected, if any;
* CHAR_NULL if match succeeded
*/
protected abstract int checkKeyword(String exp)
throws IOException, XMLStreamException;
protected abstract int readQuotedValue(char[] kw, int quoteChar)
throws IOException, XMLStreamException;
protected abstract Location getLocation();
/*
////////////////////////////////////////////////////////
// Error reporting
////////////////////////////////////////////////////////
*/
protected void reportXmlProblem(String msg)
throws XMLStreamException
{
throw new WFCException(msg, getLocation());
}
protected void reportNull()
throws XMLStreamException
{
reportXmlProblem("Illegal null byte/char in input stream");
}
protected void reportEof()
throws XMLStreamException
{
reportXmlProblem("Unexpected end-of-input in xml declaration");
}
protected void reportUnexpectedChar(int i, String msg)
throws XMLStreamException
{
String excMsg;
if (Character.isISOControl((char) i)) {
excMsg = "Unexpected character (CTRL-CHAR, code "+i+")"+msg;
} else {
excMsg = "Unexpected character '"+((char) i)+"' (code "+i+")"+msg;
}
reportXmlProblem(excMsg);
}
protected final void reportPseudoAttrProblem(String attrName, String got,
String expVal1, String expVal2)
throws XMLStreamException
{
String expStr = (expVal1 == null) ? "" :
("; expected \""+expVal1+"\" or \""+expVal2+"\"");
if (got == null || got.length() == 0) {
reportXmlProblem("Missing XML pseudo-attribute '"+attrName+"' value"+expStr);
}
reportXmlProblem("Invalid XML pseudo-attribute '"+attrName+"' value "+got+expStr);
}
}