package org.codehaus.jackson.impl;
import java.io.*;
import org.codehaus.jackson.*;
import org.codehaus.jackson.io.IOContext;
import org.codehaus.jackson.util.ByteArrayBuilder;
import org.codehaus.jackson.util.TextBuffer;
/**
* Intermediate base class used by all Jackson {@link JsonParser}
* implementations. Contains most common things that are independent
* of actual underlying input source
*
* @author Tatu Saloranta
*/
public abstract class JsonParserBase
extends JsonParser
{
// Control chars:
final static int INT_TAB = '\t';
final static int INT_LF = '\n';
final static int INT_CR = '\r';
final static int INT_SPACE = 0x0020;
// Markup
final static int INT_LBRACKET = '[';
final static int INT_RBRACKET = ']';
final static int INT_LCURLY = '{';
final static int INT_RCURLY = '}';
final static int INT_QUOTE = '"';
final static int INT_BACKSLASH = '\\';
final static int INT_SLASH = '/';
final static int INT_COLON = ':';
final static int INT_COMMA = ',';
final static int INT_ASTERISK = '*';
// Letters we need
final static int INT_b = 'b';
final static int INT_f = 'f';
final static int INT_n = 'n';
final static int INT_r = 'r';
final static int INT_t = 't';
final static int INT_u = 'u';
/*
////////////////////////////////////////////////////
// Generic I/O state
////////////////////////////////////////////////////
*/
/**
* I/O context for this reader. It handles buffer allocation
* for the reader.
*/
final protected IOContext _ioContext;
/**
* Flag that indicates whether parser is closed or not. Gets
* set when parser is either closed by explicit call
* ({@link #close}) or when end-of-input is reached.
*/
protected boolean _closed;
/*
////////////////////////////////////////////////////
// Current input data
////////////////////////////////////////////////////
*/
// Note: type of actual buffer depends on sub-class, can't include
/**
* Pointer to next available character in buffer
*/
protected int _inputPtr = 0;
/**
* Index of character after last available one in the buffer.
*/
protected int _inputEnd = 0;
/*
////////////////////////////////////////////////////
// Current input location information
////////////////////////////////////////////////////
*/
/**
* Number of characters that were contained in previous blocks
* (blocks that were already processed prior to the current buffer).
*/
protected long _currInputProcessed = 0L;
/**
* Current row location of current point in input buffer, starting
* from 1
*/
protected int _currInputRow = 1;
/**
* 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 _currInputRowStart = 0;
/*
////////////////////////////////////////////////////
// Information about starting location of event
// Reader is pointing to; updated on-demand
////////////////////////////////////////////////////
*/
// // // Location info at point when current token was started
/**
* Total number of characters read before start of current token.
* For big (gigabyte-sized) sizes are possible, needs to be long,
* unlike pointers and sizes related to in-memory buffers.
*/
protected long _tokenInputTotal = 0;
/**
* Input row on which current token starts, 1-based
*/
protected int _tokenInputRow = 1;
/**
* Column on input row that current token starts; 0-based (although
* in the end it'll be converted to 1-based)
*/
protected int _tokenInputCol = 0;
/*
////////////////////////////////////////////////////
// Parsing state
////////////////////////////////////////////////////
*/
/**
* Information about parser context, context in which
* the next token is to be parsed (root, array, object).
*/
protected JsonReadContext _parsingContext;
/**
* Secondary token related to the current token: used when
* the current token is <code>FIELD_NAME</code> but the
* actual value token is also known.
*/
protected JsonToken _nextToken;
/**
* Flag that indicates that the current token has not yet
* been fully processed, and needs to be finished for
* some access (or skipped to obtain the next token)
*/
protected boolean _tokenIncomplete = false;
/*
////////////////////////////////////////////////////
// Buffer(s) for local name(s) and text content
////////////////////////////////////////////////////
*/
/**
* Buffer that contains contents of String values, including
* field names if necessary (name split across boundary,
* contains escape sequence, or access needed to char array)
*/
protected final TextBuffer _textBuffer;
/**
* Temporary buffer that is needed if field name is accessed
* using {@link #getTextCharacters} method (instead of String
* returning alternatives)
*/
protected char[] _nameCopyBuffer = null;
/**
* Flag set to indicate whether the field name is available
* from the name copy buffer or not (in addition to its String
* representation being available via read context)
*/
protected boolean _nameCopied = false;
/**
* ByteArrayBuilder is needed if 'getBinaryValue' is called. If so,
* we better reuse it for remainder of content.
*/
ByteArrayBuilder _byteArrayBuilder = null;
/**
* We will hold on to decoded binary data, for duration of
* current event, so that multiple calls to
* {@link #getBinaryValue} will not need to decode data more
* than once.
*/
protected byte[] _binaryValue;
/*
////////////////////////////////////////////////////
// Life-cycle
////////////////////////////////////////////////////
*/
protected JsonParserBase(IOContext ctxt, int features)
{
_ioContext = ctxt;
_features = features;
_textBuffer = ctxt.constructTextBuffer();
_parsingContext = JsonReadContext.createRootContext(_tokenInputRow, _tokenInputCol);
}
/*
////////////////////////////////////////////////////
// Configuration overrides if any
////////////////////////////////////////////////////
*/
// from base class:
//public void enableFeature(Feature f)
//public void disableFeature(Feature f)
//public void setFeature(Feature f, boolean state)
//public boolean isFeatureEnabled(Feature f)
/*
////////////////////////////////////////////////////
// Abstract methods needed from sub-classes
////////////////////////////////////////////////////
*/
protected abstract void _finishString() throws IOException, JsonParseException;
/*
////////////////////////////////////////////////////
// JsonParser impl
////////////////////////////////////////////////////
*/
public abstract JsonToken nextToken()
throws IOException, JsonParseException;
public final JsonToken nextValue()
throws IOException, JsonParseException
{
/* Implementation should be as trivial as follows; only
* needs to change if we are to skip other tokens (for
* example, if comments were exposed as tokens)
*/
JsonToken t = nextToken();
if (t == JsonToken.FIELD_NAME) {
t = nextToken();
}
return t;
}
public void skipChildren()
throws IOException, JsonParseException
{
if (_currToken != JsonToken.START_OBJECT
&& _currToken != JsonToken.START_ARRAY) {
return;
}
int open = 1;
/* Since proper matching of start/end markers is handled
* by nextToken(), we'll just count nesting levels here
*/
while (true) {
JsonToken t = nextToken();
if (t == null) {
_handleEOF();
/* given constraints, above should nevert return;
* however, FindBugs doesn't know about it and
* complains... so let's add dummy break here
*/
break;
}
switch (t) {
case START_OBJECT:
case START_ARRAY:
++open;
break;
case END_OBJECT:
case END_ARRAY:
if (--open == 0) {
return;
}
break;
}
}
}
//public JsonToken getCurrentToken()
//public boolean hasCurrentToken()
/**
* Method that can be called to get the name associated with
* the current event.
*/
public String getCurrentName()
throws IOException, JsonParseException
{
return _parsingContext.getCurrentName();
}
public void close() throws IOException
{
_closed = true;
_closeInput();
// Also, internal buffer(s) can now be released as well
_releaseBuffers();
}
public boolean isClosed() { return _closed; }
public JsonReadContext getParsingContext()
{
return _parsingContext;
}
/**
* Method that return the <b>starting</b> location of the current
* token; that is, position of the first character from input
* that starts the current token.
*/
public JsonLocation getTokenLocation()
{
return new JsonLocation(_ioContext.getSourceReference(),
getTokenCharacterOffset(),
getTokenLineNr(),
getTokenColumnNr());
}
/**
* Method that returns location of the last processed character;
* usually for error reporting purposes
*/
public JsonLocation getCurrentLocation()
{
int col = _inputPtr - _currInputRowStart + 1; // 1-based
return new JsonLocation(_ioContext.getSourceReference(),
_currInputProcessed + _inputPtr - 1,
_currInputRow, col);
}
/*
////////////////////////////////////////////////////
// Public API, access to token information, text
////////////////////////////////////////////////////
*/
/**
* Method for accessing textual representation of the current event;
* if no current event (before first call to {@link #nextToken}, or
* after encountering end-of-input), returns null.
* Method can be called for any event.
*/
public String getText()
throws IOException, JsonParseException
{
if (_currToken != null) { // null only before/after document
switch (_currToken) {
case FIELD_NAME:
return _parsingContext.getCurrentName();
case VALUE_STRING:
if (_tokenIncomplete) {
_tokenIncomplete = false;
_finishString(); // only strings can be incomplete
}
// fall through
case VALUE_NUMBER_INT:
case VALUE_NUMBER_FLOAT:
return _textBuffer.contentsAsString();
default:
return _currToken.asString();
}
}
return null;
}
public char[] getTextCharacters()
throws IOException, JsonParseException
{
if (_currToken != null) { // null only before/after document
switch (_currToken) {
case FIELD_NAME:
if (!_nameCopied) {
String name = _parsingContext.getCurrentName();
int nameLen = name.length();
if (_nameCopyBuffer == null) {
_nameCopyBuffer = _ioContext.allocNameCopyBuffer(nameLen);
} else if (_nameCopyBuffer.length < nameLen) {
_nameCopyBuffer = new char[nameLen];
}
name.getChars(0, nameLen, _nameCopyBuffer, 0);
_nameCopied = true;
}
return _nameCopyBuffer;
case VALUE_STRING:
if (_tokenIncomplete) {
_tokenIncomplete = false;
_finishString(); // only strings can be incomplete
}
// fall through
case VALUE_NUMBER_INT:
case VALUE_NUMBER_FLOAT:
return _textBuffer.getTextBuffer();
default:
return _currToken.asCharArray();
}
}
return null;
}
public int getTextLength()
throws IOException, JsonParseException
{
if (_currToken != null) { // null only before/after document
switch (_currToken) {
case FIELD_NAME:
return _parsingContext.getCurrentName().length();
case VALUE_STRING:
if (_tokenIncomplete) {
_tokenIncomplete = false;
_finishString(); // only strings can be incomplete
}
// fall through
case VALUE_NUMBER_INT:
case VALUE_NUMBER_FLOAT:
return _textBuffer.size();
default:
return _currToken.asCharArray().length;
}
}
return 0;
}
public int getTextOffset()
throws IOException, JsonParseException
{
// Most have offset of 0, only some may have other values:
if (_currToken != null) {
switch (_currToken) {
case FIELD_NAME:
return 0;
case VALUE_STRING:
if (_tokenIncomplete) {
_tokenIncomplete = false;
_finishString(); // only strings can be incomplete
}
// fall through
case VALUE_NUMBER_INT:
case VALUE_NUMBER_FLOAT:
return _textBuffer.getTextOffset();
}
}
return 0;
}
/*
////////////////////////////////////////////////////
// Public API, access to token information, binary
////////////////////////////////////////////////////
*/
public final byte[] getBinaryValue(Base64Variant b64variant)
throws IOException, JsonParseException
{
if (_currToken != JsonToken.VALUE_STRING) {
_reportError("Current token ("+_currToken+") not VALUE_STRING, can not access as binary");
}
/* To ensure that we won't see inconsistent data, better clear up
* state...
*/
if (_tokenIncomplete) {
try {
_binaryValue = _decodeBase64(b64variant);
} catch (IllegalArgumentException iae) {
throw _constructError("Failed to decode VALUE_STRING as base64 ("+b64variant+"): "+iae.getMessage());
}
/* let's clear incomplete only now; allows for accessing other
* textual content in error cases
*/
_tokenIncomplete = false;
}
return _binaryValue;
}
protected abstract byte[] _decodeBase64(Base64Variant b64variant)
throws IOException, JsonParseException;
/*
////////////////////////////////////////////////////
// Public low-level accessors
////////////////////////////////////////////////////
*/
public final long getTokenCharacterOffset() { return _tokenInputTotal; }
public final int getTokenLineNr() { return _tokenInputRow; }
public final int getTokenColumnNr() { return _tokenInputCol+1; }
/*
////////////////////////////////////////////////////
// Low-level reading, other
////////////////////////////////////////////////////
*/
protected abstract boolean loadMore() throws IOException;
protected final void loadMoreGuaranteed()
throws IOException
{
if (!loadMore()) {
_reportInvalidEOF();
}
}
protected abstract void _closeInput()
throws IOException;
/**
* Method called to release internal buffers owned by the base
* reader. This may be called along with {@link #_closeInput} (for
* example, when explicitly closing this reader instance), or
* separately (if need be).
*/
protected void _releaseBuffers() throws IOException
{
_textBuffer.releaseBuffers();
char[] buf = _nameCopyBuffer;
if (buf != null) {
_nameCopyBuffer = null;
_ioContext.releaseNameCopyBuffer(buf);
}
}
/**
* Method called when an EOF is encountered between tokens.
* If so, it may be a legitimate EOF, but only iff there
* is no open non-root context.
*/
protected void _handleEOF()
throws JsonParseException
{
if (!_parsingContext.inRoot()) {
_reportInvalidEOF(": expected close marker for "+_parsingContext.getTypeDesc()+" (from "+_parsingContext.getStartLocation(_ioContext.getSourceReference())+")");
}
}
/*
////////////////////////////////////////////////////
// Error reporting
////////////////////////////////////////////////////
*/
protected void _reportUnexpectedChar(int ch, String comment)
throws JsonParseException
{
String msg = "Unexpected character ("+_getCharDesc(ch)+")";
if (comment != null) {
msg += ": "+comment;
}
_reportError(msg);
}
protected void _reportInvalidEOF()
throws JsonParseException
{
_reportInvalidEOF(" in "+_currToken);
}
protected void _reportInvalidEOF(String msg)
throws JsonParseException
{
_reportError("Unexpected end-of-input"+msg);
}
protected void _throwInvalidSpace(int i)
throws JsonParseException
{
char c = (char) i;
String msg = "Illegal character ("+_getCharDesc(c)+"): only regular white space (\\r, \\n, \\t) is allowed between tokens";
_reportError(msg);
}
protected void _throwUnquotedSpace(int i, String ctxtDesc)
throws JsonParseException
{
char c = (char) i;
String msg = "Illegal unquoted character ("+_getCharDesc(c)+"): has to be escaped using backslash to be included in "+ctxtDesc;
_reportError(msg);
}
protected void _reportMismatchedEndMarker(int actCh, char expCh)
throws JsonParseException
{
String startDesc = ""+_parsingContext.getStartLocation(_ioContext.getSourceReference());
_reportError("Unexpected close marker '"+((char) actCh)+"': expected '"+expCh+"' (for "+_parsingContext.getTypeDesc()+" starting at "+startDesc+")");
}
/*
////////////////////////////////////////////////////
// Error reporting, generic
////////////////////////////////////////////////////
*/
protected final static String _getCharDesc(int ch)
{
char c = (char) ch;
if (Character.isISOControl(c)) {
return "(CTRL-CHAR, code "+ch+")";
}
if (ch > 255) {
return "'"+c+"' (code "+ch+" / 0x"+Integer.toHexString(ch)+")";
}
return "'"+c+"' (code "+ch+")";
}
protected final void _reportError(String msg)
throws JsonParseException
{
throw _constructError(msg);
}
protected final void _wrapError(String msg, Throwable t)
throws JsonParseException
{
throw _constructError(msg, t);
}
protected final void _throwInternal()
{
throw new RuntimeException("Internal error: this code path should never get executed");
}
protected final JsonParseException _constructError(String msg)
{
return new JsonParseException(msg, getCurrentLocation());
}
protected final JsonParseException _constructError(String msg, Throwable t)
{
return new JsonParseException(msg, getCurrentLocation(), t);
}
/*
////////////////////////////////////////////////////
// Other helper methods for sub-classes
////////////////////////////////////////////////////
*/
public ByteArrayBuilder _getByteArrayBuilder()
{
if (_byteArrayBuilder == null) {
_byteArrayBuilder = new ByteArrayBuilder();
} else {
_byteArrayBuilder.reset();
}
return _byteArrayBuilder;
}
}