124 lines
3.7 KiB
Java
124 lines
3.7 KiB
Java
/*
|
|
* Copyright (C) 2009 Google Inc.
|
|
*
|
|
* 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 org.mcteam.factions.gson;
|
|
|
|
import java.io.EOFException;
|
|
import java.io.IOException;
|
|
import java.io.Reader;
|
|
import java.io.StringReader;
|
|
import java.util.Iterator;
|
|
import java.util.NoSuchElementException;
|
|
|
|
import org.mcteam.factions.gson.stream.JsonReader;
|
|
import org.mcteam.factions.gson.stream.JsonToken;
|
|
import org.mcteam.factions.gson.stream.MalformedJsonException;
|
|
|
|
|
|
/**
|
|
* A streaming parser that allows reading of multiple {@link JsonElement}s from the specified reader
|
|
* asynchronously.
|
|
*
|
|
* <p>This class is conditionally thread-safe (see Item 70, Effective Java second edition). To
|
|
* properly use this class across multiple threads, you will need to add some external
|
|
* synchronization. For example:
|
|
*
|
|
* <pre>
|
|
* JsonStreamParser parser = new JsonStreamParser("['first'] {'second':10} 'third'");
|
|
* JsonElement element;
|
|
* synchronized (parser) { // synchronize on an object shared by threads
|
|
* if (parser.hasNext()) {
|
|
* element = parser.next();
|
|
* }
|
|
* }
|
|
* </pre>
|
|
*
|
|
* @author Inderjeet Singh
|
|
* @author Joel Leitch
|
|
* @since 1.4
|
|
*/
|
|
public final class JsonStreamParser implements Iterator<JsonElement> {
|
|
|
|
private final JsonReader parser;
|
|
private final Object lock;
|
|
|
|
/**
|
|
* @param json The string containing JSON elements concatenated to each other.
|
|
* @since 1.4
|
|
*/
|
|
public JsonStreamParser(String json) {
|
|
this(new StringReader(json));
|
|
}
|
|
|
|
/**
|
|
* @param reader The data stream containing JSON elements concatenated to each other.
|
|
* @since 1.4
|
|
*/
|
|
public JsonStreamParser(Reader reader) {
|
|
parser = new JsonReader(reader);
|
|
parser.setLenient(true);
|
|
lock = new Object();
|
|
}
|
|
|
|
/**
|
|
* Returns the next available {@link JsonElement} on the reader. Null if none available.
|
|
*
|
|
* @return the next available {@link JsonElement} on the reader. Null if none available.
|
|
* @throws JsonParseException if the incoming stream is malformed JSON.
|
|
* @since 1.4
|
|
*/
|
|
public JsonElement next() throws JsonParseException {
|
|
if (!hasNext()) {
|
|
throw new NoSuchElementException();
|
|
}
|
|
|
|
try {
|
|
return Streams.parse(parser);
|
|
} catch (StackOverflowError e) {
|
|
throw new JsonParseException("Failed parsing JSON source to Json", e);
|
|
} catch (OutOfMemoryError e) {
|
|
throw new JsonParseException("Failed parsing JSON source to Json", e);
|
|
} catch (JsonParseException e) {
|
|
throw e.getCause() instanceof EOFException ? new NoSuchElementException() : e;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns true if a {@link JsonElement} is available on the input for consumption
|
|
* @return true if a {@link JsonElement} is available on the input, false otherwise
|
|
* @since 1.4
|
|
*/
|
|
public boolean hasNext() {
|
|
synchronized (lock) {
|
|
try {
|
|
return parser.peek() != JsonToken.END_DOCUMENT;
|
|
} catch (MalformedJsonException e) {
|
|
throw new JsonSyntaxException(e);
|
|
} catch (IOException e) {
|
|
throw new JsonIOException(e);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This optional {@link Iterator} method is not relevant for stream parsing and hence is not
|
|
* implemented.
|
|
* @since 1.4
|
|
*/
|
|
public void remove() {
|
|
throw new UnsupportedOperationException();
|
|
}
|
|
}
|