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/*
* Copyright (C) 2014-2024 Philip Helger (www.helger.com)
* philip[at]helger[dot]com
*
* Licensed 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.
*/
package com.helger.json.parser;
import java.io.IOException;
import java.io.Reader;
import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.WillNotClose;
import javax.annotation.concurrent.NotThreadSafe;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.helger.commons.ValueEnforcer;
import com.helger.commons.io.stream.NonBlockingPushbackReader;
import com.helger.commons.state.EEOI;
import com.helger.commons.string.StringHelper;
import com.helger.json.CJson;
import com.helger.json.parser.handler.IJsonParserHandler;
/**
* This is a generic JSON parser that invokes a custom callback for all found
* elements. This can be used as the basis for a "SAX" like JSON parsing, if
* required.
*
* @author Philip Helger
*/
@NotThreadSafe
public class JsonParser
{
private enum EStringQuoteMode
{
DOUBLE ('"'),
SINGLE ('\'');
private final char m_cQuote;
EStringQuoteMode (final char cQuote)
{
m_cQuote = cQuote;
}
public char getQuoteChar ()
{
return m_cQuote;
}
@Nonnull
public static EStringQuoteMode getFromCharOrDefault (final int c)
{
if (c == '\'')
return SINGLE;
// Default is double quotes
return DOUBLE;
}
}
/** The end of input special value */
public static final int EOI = -1;
public static final boolean DEFAULT_TRACK_POSITION = false;
public static final int DEFAULT_TAB_SIZE = 8;
public static final boolean DEFAULT_ALWAYS_USE_BIG_NUMBER = false;
public static final boolean DEFAULT_REQUIRE_STRING_QUOTES = true;
public static final boolean DEFAULT_ALLOW_SPECIAL_CHARS_IN_STRING = false;
public static final boolean DEFAULT_CHECK_FOR_EOI = true;
public static final int DEFAULT_MAX_NESTING_DEPTH = 1000;
private static final Logger LOGGER = LoggerFactory.getLogger (JsonParser.class);
private static final int MAX_PUSH_BACK_CHARS = 2;
// Constructor parameters
private final NonBlockingPushbackReader m_aReader;
private final IJsonParserHandler m_aCallback;
// Settings
private boolean m_bTrackPosition = DEFAULT_TRACK_POSITION;
private int m_nTabSize = DEFAULT_TAB_SIZE;
private boolean m_bAlwaysUseBigNumber = DEFAULT_ALWAYS_USE_BIG_NUMBER;
private boolean m_bRequireStringQuotes = DEFAULT_REQUIRE_STRING_QUOTES;
private boolean m_bAllowSpecialCharsInStrings = DEFAULT_ALLOW_SPECIAL_CHARS_IN_STRING;
private boolean m_bCheckForEOI = DEFAULT_CHECK_FOR_EOI;
private int m_nMaxNestingDepth = DEFAULT_MAX_NESTING_DEPTH;
// Status variables
// Position tracking
private final JsonParsePosition m_aParsePos = new JsonParsePosition ();
private int m_nBackupChars = 0;
private int m_nNestingLevel = 0;
// string reading cache
private final JsonStringBuilder m_aSB1 = new JsonStringBuilder (256);
private final JsonStringBuilder m_aSB2 = new JsonStringBuilder (256);
public JsonParser (@Nonnull @WillNotClose final Reader aReader, @Nonnull final IJsonParserHandler aCallback)
{
ValueEnforcer.notNull (aReader, "Reader");
ValueEnforcer.notNull (aCallback, "Callback");
// Maximum of 2 pushbacks
m_aReader = new NonBlockingPushbackReader (aReader, MAX_PUSH_BACK_CHARS);
m_aCallback = aCallback;
}
/**
* @return true if position tracking is enabled,
* false if not. By default it is disabled - see
* {@link #DEFAULT_TRACK_POSITION}
*/
public final boolean isTrackPosition ()
{
return m_bTrackPosition;
}
/**
* @param bTrackPosition
* true to track the position, false if not.
* @return this for chaining
*/
@Nonnull
public final JsonParser setTrackPosition (final boolean bTrackPosition)
{
m_bTrackPosition = bTrackPosition;
return this;
}
@Nonnegative
public final int getTabSize ()
{
return m_nTabSize;
}
@Nonnull
public final JsonParser setTabSize (@Nonnegative final int nTabSize)
{
ValueEnforcer.isGT0 (nTabSize, "TabSize");
m_nTabSize = nTabSize;
return this;
}
public final boolean isAlwaysUseBigNumber ()
{
return m_bAlwaysUseBigNumber;
}
@Nonnull
public final JsonParser setAlwaysUseBigNumber (final boolean bAlwaysUseBigNumber)
{
m_bAlwaysUseBigNumber = bAlwaysUseBigNumber;
return this;
}
public final boolean isRequireStringQuotes ()
{
return m_bRequireStringQuotes;
}
@Nonnull
public final JsonParser setRequireStringQuotes (final boolean bRequireStringQuotes)
{
m_bRequireStringQuotes = bRequireStringQuotes;
return this;
}
public final boolean isAllowSpecialCharsInStrings ()
{
return m_bAllowSpecialCharsInStrings;
}
@Nonnull
public final JsonParser setAllowSpecialCharsInStrings (final boolean bAllowSpecialCharsInStrings)
{
m_bAllowSpecialCharsInStrings = bAllowSpecialCharsInStrings;
return this;
}
/**
* @return true if a check for end of input should be performed,
* false if not. By default it is enabled for backwards
* compatibility - see {@link #DEFAULT_CHECK_FOR_EOI}
* @since 9.3.8
*/
public final boolean isCheckForEOI ()
{
return m_bCheckForEOI;
}
/**
* Enable or disable the check for end of input. This can be helpful, if an
* InputStream contains several JSON objects in a row, to read all of them in
* a single flow.
*
* @param bCheckForEOI
* true to check for EOI, false if not.
* @return this for chaining
* @since 9.3.8
*/
@Nonnull
public final JsonParser setCheckForEOI (final boolean bCheckForEOI)
{
m_bCheckForEOI = bCheckForEOI;
return this;
}
/**
* @return The maximum nesting depth of the JSON to read. Always > 0.
* @since 11.0.5
*/
@Nonnegative
public final int getMaxNestingDepth ()
{
return m_nMaxNestingDepth;
}
/**
* @param nMaxNestingDepth
* The maximum nesting depth of the JSON to read. Must be > 0.
* @return this for chaining
* @since 11.0.5
*/
@Nonnull
public final JsonParser setMaxNestingDepth (@Nonnegative final int nMaxNestingDepth)
{
ValueEnforcer.isGT0 (nMaxNestingDepth, "MaxNestingDepth");
m_nMaxNestingDepth = nMaxNestingDepth;
return this;
}
/**
* @return The current line number. First line has a value of 1.
*/
@Nonnegative
public int getLineNumber ()
{
return m_aParsePos.getLineNumber ();
}
/**
* @return The current column number. First column has a value of 1.
*/
@Nonnegative
public int getColumn ()
{
return m_aParsePos.getColumnNumber ();
}
/**
* Must return int to differentiate between the whole char range (0-0xffff)
* and EOF (-1).
*
* @return the char read or {@link #EOI} (=-1) in case of EOF
*/
private int _readChar ()
{
try
{
final int c = m_aReader.read ();
if (m_bTrackPosition)
{
if (m_nBackupChars > 0)
{
// If previously a char was backed up, don't increase the position!
m_nBackupChars--;
}
else
m_aParsePos.updatePosition (c, m_nTabSize);
}
return c;
}
catch (final IOException ex)
{
return EOI;
}
}
/**
* Backup the provided char (put it back in the queue for re-reading) if it is
* not end of input
*
* @param c
* char to backup
* @throws IllegalStateException
* in case of error
*/
private void _backupChar (final int c)
{
if (c != EOI)
try
{
m_aReader.unread (c);
m_nBackupChars++;
}
catch (final IOException ex)
{
throw new IllegalStateException ("Failed to unread character " + _getPrintableChar (c));
}
}
@Nonnull
private static String _getPrintableChar (final int c)
{
if (c == EOI)
return "";
if (c <= 32)
return "0x" + StringHelper.getHexStringLeadingZero (c, 2);
if (c >= 127)
return "0x" + StringHelper.getHexStringLeadingZero (c, 4);
return "'" + (char) c + "'";
}
@Nonnull
private JsonParseException _parseEx (@Nullable final IJsonParsePosition aTokenStart, @Nonnull final String sMsg)
{
if (m_bTrackPosition)
return new JsonParseException (aTokenStart, m_aParsePos, sMsg);
return new JsonParseException (sMsg);
}
@Nullable
private IJsonParsePosition _getCurrentParsePos ()
{
return m_bTrackPosition ? m_aParsePos.getClone () : null;
}
private void _readComment () throws JsonParseException
{
final IJsonParsePosition aStartPos = _getCurrentParsePos ();
// Use SB2 because _skipSpaces uses SB1
final JsonStringBuilder aStrComment = m_aSB2.reset ();
while (true)
{
final int c1 = _readChar ();
if (c1 == '*')
{
// End of comment?
final int c2 = _readChar ();
if (c2 == '/')
{
// End of comment!
m_aCallback.onComment (aStrComment.getAsString ());
return;
}
if (c2 == EOI)
throw _parseEx (aStartPos, "Unclosed JSON comment at end of input");
// Backup the "/" try
_backupChar (c2);
}
if (c1 == EOI)
throw _parseEx (aStartPos, "Unclosed JSON comment at end of input");
aStrComment.append ((char) c1);
}
}
private void _skipSpaces () throws JsonParseException
{
final JsonStringBuilder aStrSpaces = m_aSB1.reset ();
while (true)
{
final int c = _readChar ();
// Check for comment
if (c == '/')
{
final int c2 = _readChar ();
if (c2 == '*')
{
if (aStrSpaces.hasContent ())
{
// Notify on previous whitespaces
m_aCallback.onWhitespace (aStrSpaces.getAsString ());
aStrSpaces.reset ();
}
// start comment
_readComment ();
// Finished comment - check for next whitespace
continue;
}
// backup c2 as it is no comment
_backupChar (c2);
}
if (c != ' ' && c != '\t' && c != '\r' && c != '\n' && c != '\f')
{
// End of whitespaces reached
if (aStrSpaces.hasContent ())
m_aCallback.onWhitespace (aStrSpaces.getAsString ());
// backup c - if previously c2 was backed up this is where we need 2
// chars pushback :)
_backupChar (c);
return;
}
// It's a whitespace character
aStrSpaces.append ((char) c);
}
}
/**
* @param aStartPos
* Optional parsing start position
* @param c
* character
* @return The int representation of the read hex char (0-9, a-f)
* @throws JsonParseException
* In case a non hex char was encountered
*/
private int _getHexValue (@Nullable final IJsonParsePosition aStartPos, final int c) throws JsonParseException
{
final int ret = StringHelper.getHexValue ((char) c);
if (ret == -1)
throw _parseEx (aStartPos, "Invalid hex character " + _getPrintableChar (c) + " provided!");
return ret;
}
private void _readStringEscapeChar (@Nonnull final IJsonParsePosition aStartPos,
@Nonnull final JsonStringBuilder aStrStringOriginalContent,
@Nonnull final JsonStringBuilder aStrStringUnescapedContent) throws JsonParseException
{
final int c2 = _readChar ();
aStrStringOriginalContent.append ((char) c2);
if (c2 == '"' || c2 == '/' || c2 == '\\')
aStrStringUnescapedContent.append ((char) c2);
else
if (c2 == 'b')
aStrStringUnescapedContent.append ('\b');
else
if (c2 == 'f')
aStrStringUnescapedContent.append ('\f');
else
if (c2 == 'n')
aStrStringUnescapedContent.append ('\n');
else
if (c2 == 'r')
aStrStringUnescapedContent.append ('\r');
else
if (c2 == 't')
aStrStringUnescapedContent.append ('\t');
else
if (c2 == 'u')
{
final int ch0 = _readChar ();
final int n0 = _getHexValue (aStartPos, ch0);
final int ch1 = _readChar ();
final int n1 = _getHexValue (aStartPos, ch1);
final int ch2 = _readChar ();
final int n2 = _getHexValue (aStartPos, ch2);
final int ch3 = _readChar ();
final int n3 = _getHexValue (aStartPos, ch3);
aStrStringOriginalContent.append ((char) ch0);
aStrStringOriginalContent.append ((char) ch1);
aStrStringOriginalContent.append ((char) ch2);
aStrStringOriginalContent.append ((char) ch3);
final int nUnescapedChar = (n0 & 0xff) << 12 | (n1 & 0xff) << 8 | (n2 & 0xff) << 4 | (n3 & 0xff);
aStrStringUnescapedContent.append ((char) nUnescapedChar);
}
else
throw _parseEx (aStartPos, "Invalid JSON String escape character " + _getPrintableChar (c2));
}
private static boolean _isUnquotedStringValidChar (final int c)
{
return (c >= 0x21 && c <= 0x7a) && c != ':';
}
private static final class TwoStrings
{
private final String m_sOriginal;
private final String m_sUnescaped;
private TwoStrings (@Nonnull final String sOriginal, @Nonnull final String sUnescaped)
{
m_sOriginal = sOriginal;
m_sUnescaped = sUnescaped;
}
}
/**
* @param eQuoteMode
* The quoting mode used. May not be null.
* @return A pair where the first string is the original read string whereas
* the second part is the unescaped read string without leading and
* trailing quotes
* @throws JsonParseException
*/
@Nonnull
private TwoStrings _readString (@Nonnull final EStringQuoteMode eQuoteMode) throws JsonParseException
{
final IJsonParsePosition aStartPos = _getCurrentParsePos ();
final JsonStringBuilder aStrStringOriginalContent = m_aSB1.reset ();
final JsonStringBuilder aStrStringUnescapedContent = m_aSB2.reset ();
final int cQuoteChar = eQuoteMode.getQuoteChar ();
final int cStart = _readChar ();
final boolean bStringIsQuoted = cStart == cQuoteChar;
if (bStringIsQuoted)
{
aStrStringOriginalContent.append ((char) cQuoteChar);
}
else
{
if (m_bRequireStringQuotes)
throw _parseEx (aStartPos,
"Invalid JSON String start character " +
_getPrintableChar (cStart) +
" - expected " +
_getPrintableChar (cQuoteChar));
_backupChar (cStart);
aStrStringOriginalContent.append ((char) cQuoteChar);
}
outer: while (true)
{
final int c = _readChar ();
aStrStringOriginalContent.append ((char) c);
switch (c)
{
case '\\':
{
// Escape char
_readStringEscapeChar (aStartPos, aStrStringOriginalContent, aStrStringUnescapedContent);
break;
}
case EOI:
throw _parseEx (aStartPos, "Unclosed JSON String at end of input");
case '\b':
case '\f':
case '\n':
case '\r':
case '\t':
if (!m_bAllowSpecialCharsInStrings)
throw _parseEx (aStartPos, "Invalid JSON String character " + _getPrintableChar (c));
// else fall-though!
default:
if (bStringIsQuoted)
{
if (c == cQuoteChar)
{
// End of quoted string
// No append to unescaped content
break outer;
}
}
else
{
if (!_isUnquotedStringValidChar (c))
{
// End of unquoted string
// Remove from original content
_backupChar (c);
aStrStringOriginalContent.backup (1);
if (aStrStringUnescapedContent.getLength () == 0)
throw _parseEx (aStartPos, "Empty unquoted JSON String encountered");
// Since it is present on open, it must also be present on close
aStrStringOriginalContent.append ((char) cQuoteChar);
break outer;
}
}
// Regular string character
aStrStringUnescapedContent.append ((char) c);
break;
}
}
return new TwoStrings (aStrStringOriginalContent.getAsString (), aStrStringUnescapedContent.getAsString ());
}
@Nonnull
private static Number _parseNumberInt (@Nonnull final JsonStringBuilder s)
{
final int nLen = s.getLength ();
// pos
int nPos = 0;
// max pos long base 10 len
int nMax = 19;
final boolean bNeg = s.charAt (0) == '-';
if (bNeg)
{
nPos++;
nMax++;
}
if (nLen > nMax)
{
// BigInteger anyway
return s.getAsBigInteger ();
}
boolean bMustCheck;
if (nLen < nMax)
{
// Never BigInteger
nMax = nLen;
bMustCheck = false;
}
else
{
// nLen == nMax
nMax = nLen - 1;
bMustCheck = true;
}
// r gets negative since the negative maximas are 1 "larger" than the
// positive maximas
long r = 0;
while (nPos < nMax)
r = (r * 10L) + ('0' - s.charAt (nPos++));
if (bMustCheck)
{
final boolean bIsBig;
if (r > -922337203685477580L)
{
bIsBig = false;
}
else
if (r < -922337203685477580L)
{
bIsBig = true;
}
else
{
if (bNeg)
bIsBig = s.charAt (nPos) > '8';
else
bIsBig = s.charAt (nPos) > '7';
}
if (bIsBig)
return s.getAsBigInteger ();
// Add the last char
r = (r * 10L) + ('0' - s.charAt (nPos));
}
if (!bNeg)
r = -r;
if (r >= Integer.MIN_VALUE && r <= Integer.MAX_VALUE)
return Integer.valueOf ((int) r);
return Long.valueOf (r);
}
@Nonnull
private Number _parseNumber (@Nonnull final IJsonParsePosition aStartPos,
final boolean bIsDecimal,
final boolean bHasExponent,
final boolean bHasPositiveExponent,
@Nonnull final JsonStringBuilder aNumChars) throws JsonParseException
{
try
{
final int nCharCount = aNumChars.getLength ();
if (bIsDecimal)
{
// Decimal number
if (nCharCount > 18 || m_bAlwaysUseBigNumber)
return aNumChars.getAsBigDecimal ();
return aNumChars.getAsDouble ();
}
if (bHasExponent)
{
// Integer number
if (bHasPositiveExponent)
{
// Required for correct "e" handling
return aNumChars.getAsBigDecimal ().toBigIntegerExact ();
}
// Required for correct "e" handling
return aNumChars.getAsBigDecimal ();
}
// No exponent present
if (m_bAlwaysUseBigNumber)
return aNumChars.getAsBigInteger ();
return _parseNumberInt (aNumChars);
}
catch (final NumberFormatException ex)
{
// This should never happen, as our consistency check beforehand are quite
// okay :)
throw _parseEx (aStartPos, "Invalid JSON Number '" + aNumChars.getAsString () + "'");
}
}
private void _readNumber () throws JsonParseException
{
final IJsonParsePosition aStartPos = _getCurrentParsePos ();
final JsonStringBuilder aStrNumber = m_aSB1.reset ();
int c = _readChar ();
if (c == '-')
{
// Leading minus?
// Note: leading plus is not allowed
aStrNumber.append ((char) c);
c = _readChar ();
}
if (c == '0')
{
// No additional numbers allowed
aStrNumber.append ((char) c);
c = _readChar ();
}
else
if (c >= '1' && c <= '9')
{
aStrNumber.append ((char) c);
c = _readChar ();
while (c >= '0' && c <= '9')
{
aStrNumber.append ((char) c);
c = _readChar ();
}
}
else
throw _parseEx (aStartPos, "Invalid JSON Number start character " + _getPrintableChar (c));
final boolean bIsDecimal = c == '.';
if (bIsDecimal)
{
// read decimal part
aStrNumber.append ((char) c);
c = _readChar ();
boolean bDecimalDigits = false;
while (c >= '0' && c <= '9')
{
aStrNumber.append ((char) c);
bDecimalDigits = true;
c = _readChar ();
}
if (!bDecimalDigits)
throw _parseEx (aStartPos,
"Missing digits after decimal point in JSON Number '" + aStrNumber.getAsString () + "'");
}
final boolean bHasExponent = c == 'e' || c == 'E';
boolean bHasPositiveExponent = false;
if (bHasExponent)
{
// read exponent
aStrNumber.append ((char) c);
c = _readChar ();
// Any char other than "-" means the exponent is positive
bHasPositiveExponent = c != '-';
if (c == '+' || c == '-')
{
aStrNumber.append ((char) c);
c = _readChar ();
}
boolean bExponentDigits = false;
while (c >= '0' && c <= '9')
{
aStrNumber.append ((char) c);
bExponentDigits = true;
c = _readChar ();
}
if (!bExponentDigits)
throw _parseEx (aStartPos,
"Missing digits after exponent sign in JSON Number '" + aStrNumber.getAsString () + "'");
}
// Backup last (unused) char
_backupChar (c);
final Number aNum = _parseNumber (aStartPos, bIsDecimal, bHasExponent, bHasPositiveExponent, aStrNumber);
m_aCallback.onNumber (aStrNumber.getAsString (), aNum);
}
private void _expect (@Nonnull final String sKeyword) throws JsonParseException
{
final IJsonParsePosition aStartPos = _getCurrentParsePos ();
for (final char cExpected : sKeyword.toCharArray ())
{
final int c = _readChar ();
if (c != cExpected)
throw _parseEx (aStartPos,
"Expected " +
_getPrintableChar (cExpected) +
" but got " +
_getPrintableChar (c) +
" as part of JSON keyword \"" +
sKeyword +
"\"");
}
}
private void _readArray () throws JsonParseException
{
final IJsonParsePosition aStartPos = _getCurrentParsePos ();
m_aCallback.onArrayStart ();
int nIndex = 0;
while (true)
{
_skipSpaces ();
// Check for empty array
int c = _readChar ();
if (c == CJson.ARRAY_END)
{
if (nIndex != 0)
throw _parseEx (aStartPos, "Expected another element in JSON Array");
break;
}
_backupChar (c);
_readValue ();
_skipSpaces ();
c = _readChar ();
if (c == CJson.ITEM_SEPARATOR)
{
++nIndex;
m_aCallback.onArrayNextElement ();
continue;
}
if (c == CJson.ARRAY_END)
break;
throw _parseEx (aStartPos, "Unexpected character " + _getPrintableChar (c) + " in JSON array");
}
m_aCallback.onArrayEnd ();
}
private void _readObject () throws JsonParseException
{
final IJsonParsePosition aStartPos = _getCurrentParsePos ();
m_aCallback.onObjectStart ();
int nIndex = 0;
while (true)
{
_skipSpaces ();
// Check for empty object
int c = _readChar ();
if (c == CJson.OBJECT_END)
{
if (nIndex != 0)
throw _parseEx (aStartPos, "Expected another element in JSON Object");
break;
}
final EStringQuoteMode eQuoteMode = EStringQuoteMode.getFromCharOrDefault (c);
_backupChar (c);
final TwoStrings aName = _readString (eQuoteMode);
m_aCallback.onObjectName (aName.m_sOriginal, aName.m_sUnescaped);
_skipSpaces ();
c = _readChar ();
if (c != CJson.NAME_VALUE_SEPARATOR)
throw _parseEx (aStartPos, "Expected colon character in JSON Object but found " + _getPrintableChar (c));
m_aCallback.onObjectColon ();
_skipSpaces ();
_readValue ();
_skipSpaces ();
c = _readChar ();
if (c == CJson.ITEM_SEPARATOR)
{
// element following
++nIndex;
m_aCallback.onObjectNextElement ();
}
else
{
if (c == CJson.OBJECT_END)
{
// End of object
break;
}
// Syntax error
throw _parseEx (aStartPos, "Unexpected character " + _getPrintableChar (c) + " in JSON Object");
}
}
m_aCallback.onObjectEnd ();
}
private void _incNestingLevel (@Nullable final IJsonParsePosition aTokenStart) throws JsonParseException
{
m_nNestingLevel++;
if (m_nNestingLevel > m_nMaxNestingDepth)
throw _parseEx (aTokenStart,
"The nesting level " +
m_nNestingLevel +
" exceeds the maximum nesting level of " +
m_nMaxNestingDepth);
}
private void _decNestingLevel ()
{
m_nNestingLevel--;
if (m_nNestingLevel < 0)
LOGGER.warn ("Internal inconsistency: nesting level < 0: " + m_nNestingLevel);
}
/**
* Read a single value
*
* @return {@link EEOI#CONTINUE} if something was read, {@link EEOI#EOI} if
* there was an EOI
* @throws JsonParseException
* In case of parse exceptions
*/
@Nonnull
private EEOI _readValue () throws JsonParseException
{
_skipSpaces ();
final IJsonParsePosition aStartPos = _getCurrentParsePos ();
final int cFirst = _readChar ();
switch (cFirst)
{
case '\'':
{
_backupChar (cFirst);
final TwoStrings aString = _readString (EStringQuoteMode.SINGLE);
m_aCallback.onString (aString.m_sOriginal, aString.m_sUnescaped);
break;
}
case '"':
{
_backupChar (cFirst);
final TwoStrings aString = _readString (EStringQuoteMode.DOUBLE);
m_aCallback.onString (aString.m_sOriginal, aString.m_sUnescaped);
break;
}
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
_backupChar (cFirst);
_readNumber ();
break;
case 't':
_backupChar (cFirst);
_expect (CJson.KEYWORD_TRUE);
m_aCallback.onTrue ();
break;
case 'f':
_backupChar (cFirst);
_expect (CJson.KEYWORD_FALSE);
m_aCallback.onFalse ();
break;
case 'n':
_backupChar (cFirst);
_expect (CJson.KEYWORD_NULL);
m_aCallback.onNull ();
break;
case CJson.ARRAY_START:
_incNestingLevel (aStartPos);
_readArray ();
_decNestingLevel ();
break;
case CJson.OBJECT_START:
_incNestingLevel (aStartPos);
_readObject ();
_decNestingLevel ();
break;
case EOI:
return EEOI.EOI;
default:
throw _parseEx (aStartPos, "Syntax error in JSON. Found " + _getPrintableChar (cFirst));
}
return EEOI.NOT_EOI;
}
/**
* Main parsing routine
*
* @return {@link EEOI#NOT_EOI} if something was read, {@link EEOI#EOI} if
* there was an EOI
* @throws JsonParseException
* In case a parse error occurs.
*/
@Nonnull
public EEOI parse () throws JsonParseException
{
final EEOI eEOI = _readValue ();
if (eEOI.isNotEndOfInput () && m_bCheckForEOI)
{
// Non EOF
// Check for trailing whitespaces (reads a char)
_skipSpaces ();
final IJsonParsePosition aStartPos = _getCurrentParsePos ();
// Check for expected end of input
final int c = _readChar ();
if (c != EOI)
throw _parseEx (aStartPos, "Invalid character " + _getPrintableChar (c) + " after JSON root object");
}
return eEOI;
}
}
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