org.glassfish.json.JsonParserImpl Maven / Gradle / Ivy
/*
* Copyright (c) 2012, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.json;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.math.BigDecimal;
import java.nio.charset.Charset;
import java.util.AbstractMap;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.Consumer;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
import javax.json.JsonArray;
import javax.json.JsonArrayBuilder;
import javax.json.JsonException;
import javax.json.JsonObject;
import javax.json.JsonObjectBuilder;
import javax.json.JsonValue;
import javax.json.stream.JsonLocation;
import javax.json.stream.JsonParser;
import javax.json.stream.JsonParser.Event;
import javax.json.stream.JsonParsingException;
import org.glassfish.json.JsonTokenizer.JsonToken;
import org.glassfish.json.api.BufferPool;
/**
* JSON parser implementation. NoneContext, ArrayContext, ObjectContext is used
* to go to next parser state.
*
* @author Jitendra Kotamraju
* @author Kin-man Chung
*/
public class JsonParserImpl implements JsonParser {
private final BufferPool bufferPool;
private Context currentContext = new NoneContext();
private Event currentEvent;
private final Stack stack = new Stack();
private final JsonTokenizer tokenizer;
public JsonParserImpl(Reader reader, BufferPool bufferPool) {
this.bufferPool = bufferPool;
tokenizer = new JsonTokenizer(reader, bufferPool);
}
public JsonParserImpl(InputStream in, BufferPool bufferPool) {
this.bufferPool = bufferPool;
UnicodeDetectingInputStream uin = new UnicodeDetectingInputStream(in);
tokenizer = new JsonTokenizer(new InputStreamReader(uin, uin.getCharset()), bufferPool);
}
public JsonParserImpl(InputStream in, Charset encoding, BufferPool bufferPool) {
this.bufferPool = bufferPool;
tokenizer = new JsonTokenizer(new InputStreamReader(in, encoding), bufferPool);
}
@Override
public String getString() {
if (currentEvent == Event.KEY_NAME || currentEvent == Event.VALUE_STRING
|| currentEvent == Event.VALUE_NUMBER) {
return tokenizer.getValue();
}
throw new IllegalStateException(
JsonMessages.PARSER_GETSTRING_ERR(currentEvent));
}
@Override
public boolean isIntegralNumber() {
if (currentEvent != Event.VALUE_NUMBER) {
throw new IllegalStateException(
JsonMessages.PARSER_ISINTEGRALNUMBER_ERR(currentEvent));
}
return tokenizer.isIntegral();
}
@Override
public int getInt() {
if (currentEvent != Event.VALUE_NUMBER) {
throw new IllegalStateException(
JsonMessages.PARSER_GETINT_ERR(currentEvent));
}
return tokenizer.getInt();
}
boolean isDefinitelyInt() {
return tokenizer.isDefinitelyInt();
}
boolean isDefinitelyLong() {
return tokenizer.isDefinitelyLong();
}
@Override
public long getLong() {
if (currentEvent != Event.VALUE_NUMBER) {
throw new IllegalStateException(
JsonMessages.PARSER_GETLONG_ERR(currentEvent));
}
return tokenizer.getLong();
}
@Override
public BigDecimal getBigDecimal() {
if (currentEvent != Event.VALUE_NUMBER) {
throw new IllegalStateException(
JsonMessages.PARSER_GETBIGDECIMAL_ERR(currentEvent));
}
return tokenizer.getBigDecimal();
}
@Override
public JsonArray getArray() {
if (currentEvent != Event.START_ARRAY) {
throw new IllegalStateException(
JsonMessages.PARSER_GETARRAY_ERR(currentEvent));
}
return getArray(new JsonArrayBuilderImpl(bufferPool));
}
@Override
public JsonObject getObject() {
if (currentEvent != Event.START_OBJECT) {
throw new IllegalStateException(
JsonMessages.PARSER_GETOBJECT_ERR(currentEvent));
}
return getObject(new JsonObjectBuilderImpl(bufferPool));
}
@Override
public JsonValue getValue() {
switch (currentEvent) {
case START_ARRAY:
return getArray(new JsonArrayBuilderImpl(bufferPool));
case START_OBJECT:
return getObject(new JsonObjectBuilderImpl(bufferPool));
case KEY_NAME:
case VALUE_STRING:
return new JsonStringImpl(getString());
case VALUE_NUMBER:
if (isDefinitelyInt()) {
return JsonNumberImpl.getJsonNumber(getInt());
} else if (isDefinitelyLong()) {
return JsonNumberImpl.getJsonNumber(getLong());
}
return JsonNumberImpl.getJsonNumber(getBigDecimal());
case VALUE_TRUE:
return JsonValue.TRUE;
case VALUE_FALSE:
return JsonValue.FALSE;
case VALUE_NULL:
return JsonValue.NULL;
case END_ARRAY:
case END_OBJECT:
default:
throw new IllegalStateException(JsonMessages.PARSER_GETVALUE_ERR(currentEvent));
}
}
@Override
public Stream getArrayStream() {
if (currentEvent != Event.START_ARRAY) {
throw new IllegalStateException(
JsonMessages.PARSER_GETARRAY_ERR(currentEvent));
}
Spliterator spliterator =
new Spliterators.AbstractSpliterator(Long.MAX_VALUE, Spliterator.ORDERED) {
@Override
public Spliterator trySplit() {
return null;
}
@Override
public boolean tryAdvance(Consumer action) {
if (action == null) {
throw new NullPointerException();
}
if (! hasNext()) {
return false;
}
if (next() == JsonParser.Event.END_ARRAY) {
return false;
}
action.accept(getValue());
return true;
}
};
return StreamSupport.stream(spliterator, false);
}
@Override
public Stream> getObjectStream() {
if (currentEvent != Event.START_OBJECT) {
throw new IllegalStateException(
JsonMessages.PARSER_GETOBJECT_ERR(currentEvent));
}
Spliterator> spliterator =
new Spliterators.AbstractSpliterator>(Long.MAX_VALUE, Spliterator.ORDERED) {
@Override
public Spliterator> trySplit() {
return null;
}
@Override
public boolean tryAdvance(Consumer> action) {
if (action == null) {
throw new NullPointerException();
}
if (! hasNext()) {
return false;
}
JsonParser.Event e = next();
if (e == JsonParser.Event.END_OBJECT) {
return false;
}
if (e != JsonParser.Event.KEY_NAME) {
throw new JsonException(JsonMessages.INTERNAL_ERROR());
}
String key = getString();
if (! hasNext()) {
throw new JsonException(JsonMessages.INTERNAL_ERROR());
}
next();
JsonValue value = getValue();
action.accept(new AbstractMap.SimpleImmutableEntry<>(key, value));
return true;
}
};
return StreamSupport.stream(spliterator, false);
}
@Override
public Stream getValueStream() {
if (! (currentContext instanceof NoneContext)) {
throw new IllegalStateException(
JsonMessages.PARSER_GETVALUESTREAM_ERR());
}
Spliterator spliterator =
new Spliterators.AbstractSpliterator(Long.MAX_VALUE, Spliterator.ORDERED) {
@Override
public Spliterator trySplit() {
return null;
}
@Override
public boolean tryAdvance(Consumer action) {
if (action == null) {
throw new NullPointerException();
}
if (! hasNext()) {
return false;
}
next();
action.accept(getValue());
return true;
}
};
return StreamSupport.stream(spliterator, false);
}
@Override
public void skipArray() {
if (currentEvent == Event.START_ARRAY) {
currentContext.skip();
currentContext = stack.pop();
currentEvent = Event.END_ARRAY;
}
}
@Override
public void skipObject() {
if (currentEvent == Event.START_OBJECT) {
currentContext.skip();
currentContext = stack.pop();
currentEvent = Event.END_OBJECT;
}
}
private JsonArray getArray(JsonArrayBuilder builder) {
while(hasNext()) {
JsonParser.Event e = next();
if (e == JsonParser.Event.END_ARRAY) {
return builder.build();
}
builder.add(getValue());
}
throw parsingException(JsonToken.EOF, "[CURLYOPEN, SQUAREOPEN, STRING, NUMBER, TRUE, FALSE, NULL, SQUARECLOSE]");
}
private JsonObject getObject(JsonObjectBuilder builder) {
while(hasNext()) {
JsonParser.Event e = next();
if (e == JsonParser.Event.END_OBJECT) {
return builder.build();
}
String key = getString();
next();
builder.add(key, getValue());
}
throw parsingException(JsonToken.EOF, "[STRING, CURLYCLOSE]");
}
@Override
public JsonLocation getLocation() {
return tokenizer.getLocation();
}
public JsonLocation getLastCharLocation() {
return tokenizer.getLastCharLocation();
}
@Override
public boolean hasNext() {
if (stack.isEmpty() && (currentEvent != null && currentEvent.compareTo(Event.KEY_NAME) > 0)) {
JsonToken token = tokenizer.nextToken();
if (token != JsonToken.EOF) {
throw new JsonParsingException(JsonMessages.PARSER_EXPECTED_EOF(token),
getLastCharLocation());
}
return false;
} else if (!stack.isEmpty() && !tokenizer.hasNextToken()) {
currentEvent = currentContext.getNextEvent();
return false;
}
return true;
}
@Override
public Event next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
return currentEvent = currentContext.getNextEvent();
}
@Override
public void close() {
try {
tokenizer.close();
} catch (IOException e) {
throw new JsonException(JsonMessages.PARSER_TOKENIZER_CLOSE_IO(), e);
}
}
// Using the optimized stack impl as we don't require other things
// like iterator etc.
private static final class Stack {
private Context head;
private void push(Context context) {
context.next = head;
head = context;
}
private Context pop() {
if (head == null) {
throw new NoSuchElementException();
}
Context temp = head;
head = head.next;
return temp;
}
private Context peek() {
return head;
}
private boolean isEmpty() {
return head == null;
}
}
private abstract class Context {
Context next;
abstract Event getNextEvent();
abstract void skip();
}
private final class NoneContext extends Context {
@Override
public Event getNextEvent() {
// Handle 1. { 2. [ 3. value
JsonToken token = tokenizer.nextToken();
if (token == JsonToken.CURLYOPEN) {
stack.push(currentContext);
currentContext = new ObjectContext();
return Event.START_OBJECT;
} else if (token == JsonToken.SQUAREOPEN) {
stack.push(currentContext);
currentContext = new ArrayContext();
return Event.START_ARRAY;
} else if (token.isValue()) {
return token.getEvent();
}
throw parsingException(token, "[CURLYOPEN, SQUAREOPEN, STRING, NUMBER, TRUE, FALSE, NULL]");
}
@Override
void skip() {
// no-op
}
}
private JsonParsingException parsingException(JsonToken token, String expectedTokens) {
JsonLocation location = getLastCharLocation();
return new JsonParsingException(
JsonMessages.PARSER_INVALID_TOKEN(token, location, expectedTokens), location);
}
private final class ObjectContext extends Context {
private boolean firstValue = true;
/*
* Some more things could be optimized. For example, instead
* tokenizer.nextToken(), one could use tokenizer.matchColonToken() to
* match ':'. That might optimize a bit, but will fragment nextToken().
* I think the current one is more readable.
*
*/
@Override
public Event getNextEvent() {
// Handle 1. } 2. name:value 3. ,name:value
JsonToken token = tokenizer.nextToken();
if (token == JsonToken.EOF) {
switch (currentEvent) {
case START_OBJECT:
throw parsingException(token, "[STRING, CURLYCLOSE]");
case KEY_NAME:
throw parsingException(token, "[COLON]");
default:
throw parsingException(token, "[COMMA, CURLYCLOSE]");
}
} else if (currentEvent == Event.KEY_NAME) {
// Handle 1. :value
if (token != JsonToken.COLON) {
throw parsingException(token, "[COLON]");
}
token = tokenizer.nextToken();
if (token.isValue()) {
return token.getEvent();
} else if (token == JsonToken.CURLYOPEN) {
stack.push(currentContext);
currentContext = new ObjectContext();
return Event.START_OBJECT;
} else if (token == JsonToken.SQUAREOPEN) {
stack.push(currentContext);
currentContext = new ArrayContext();
return Event.START_ARRAY;
}
throw parsingException(token, "[CURLYOPEN, SQUAREOPEN, STRING, NUMBER, TRUE, FALSE, NULL]");
} else {
// Handle 1. } 2. name 3. ,name
if (token == JsonToken.CURLYCLOSE) {
currentContext = stack.pop();
return Event.END_OBJECT;
}
if (firstValue) {
firstValue = false;
} else {
if (token != JsonToken.COMMA) {
throw parsingException(token, "[COMMA]");
}
token = tokenizer.nextToken();
}
if (token == JsonToken.STRING) {
return Event.KEY_NAME;
}
throw parsingException(token, "[STRING]");
}
}
@Override
void skip() {
JsonToken token;
int depth = 1;
do {
token = tokenizer.nextToken();
switch (token) {
case CURLYCLOSE:
depth--;
break;
case CURLYOPEN:
depth++;
break;
}
} while (!(token == JsonToken.CURLYCLOSE && depth == 0));
}
}
private final class ArrayContext extends Context {
private boolean firstValue = true;
// Handle 1. ] 2. value 3. ,value
@Override
public Event getNextEvent() {
JsonToken token = tokenizer.nextToken();
if (token == JsonToken.EOF) {
switch (currentEvent) {
case START_ARRAY:
throw parsingException(token, "[CURLYOPEN, SQUAREOPEN, STRING, NUMBER, TRUE, FALSE, NULL]");
default:
throw parsingException(token, "[COMMA, CURLYCLOSE]");
}
}
if (token == JsonToken.SQUARECLOSE) {
currentContext = stack.pop();
return Event.END_ARRAY;
}
if (firstValue) {
firstValue = false;
} else {
if (token != JsonToken.COMMA) {
throw parsingException(token, "[COMMA]");
}
token = tokenizer.nextToken();
}
if (token.isValue()) {
return token.getEvent();
} else if (token == JsonToken.CURLYOPEN) {
stack.push(currentContext);
currentContext = new ObjectContext();
return Event.START_OBJECT;
} else if (token == JsonToken.SQUAREOPEN) {
stack.push(currentContext);
currentContext = new ArrayContext();
return Event.START_ARRAY;
}
throw parsingException(token, "[CURLYOPEN, SQUAREOPEN, STRING, NUMBER, TRUE, FALSE, NULL]");
}
@Override
void skip() {
JsonToken token;
int depth = 1;
do {
token = tokenizer.nextToken();
switch (token) {
case SQUARECLOSE:
depth--;
break;
case SQUAREOPEN:
depth++;
break;
}
} while (!(token == JsonToken.SQUARECLOSE && depth == 0));
}
}
}
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