/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.elasticsearch.hadoop.serialization.json;
import java.io.IOException;
import java.util.Iterator;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.JsonStreamContext;
import org.codehaus.jackson.JsonToken;
import org.codehaus.jackson.map.DeserializationContext;
import org.codehaus.jackson.map.JsonDeserializer;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.RuntimeJsonMappingException;
import org.codehaus.jackson.type.JavaType;
/**
* Backported class from Jackson 1.8.8 for Jackson 1.5.2
*
* Iterator exposed by {@link ObjectMapper} when binding sequence of
* objects. Extension is done to allow more convenient exposing of
* {@link IOException} (which basic {@link Iterator} does not expose)
*
* @since 1.8
*/
class BackportedJacksonMappingIterator<T> implements Iterator<T> {
protected final static BackportedJacksonMappingIterator<?> EMPTY_ITERATOR = new BackportedJacksonMappingIterator<Object>(null, null, null, null);
protected final JavaType _type;
protected final DeserializationContext _context;
protected final JsonDeserializer<T> _deserializer;
protected final JsonParser _parser;
@SuppressWarnings("unchecked")
protected BackportedJacksonMappingIterator(JavaType type, JsonParser jp, DeserializationContext ctxt, JsonDeserializer<?> deser) {
_type = type;
_parser = jp;
_context = ctxt;
_deserializer = (JsonDeserializer<T>) deser;
/* One more thing: if we are at START_ARRAY (but NOT root-level
* one!), advance to next token (to allow matching END_ARRAY)
*/
if (jp != null && jp.getCurrentToken() == JsonToken.START_ARRAY) {
JsonStreamContext sc = jp.getParsingContext();
// safest way to skip current token is to clear it (so we'll advance soon)
if (!sc.inRoot()) {
jp.clearCurrentToken();
}
}
}
@SuppressWarnings("unchecked")
protected static <T> BackportedJacksonMappingIterator<T> emptyIterator() {
return (BackportedJacksonMappingIterator<T>) EMPTY_ITERATOR;
}
/*
/**********************************************************
/* Basic iterator impl
/**********************************************************
*/
@Override
public boolean hasNext() {
try {
return hasNextValue();
} catch (JsonMappingException e) {
throw new RuntimeJsonMappingException(e.getMessage(), e);
} catch (IOException e) {
throw new RuntimeException(e.getMessage(), e);
}
}
@Override
public T next() {
try {
return nextValue();
} catch (JsonMappingException e) {
throw new RuntimeJsonMappingException(e.getMessage(), e);
} catch (IOException e) {
throw new RuntimeException(e.getMessage(), e);
}
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
/*
/**********************************************************
/* Extended API
/**********************************************************
*/
/**
* Equivalent of {@link #next} but one that may throw checked
* exceptions from Jackson due to invalid input.
*/
public boolean hasNextValue() throws IOException {
if (_parser == null) {
return false;
}
JsonToken t = _parser.getCurrentToken();
if (t == null) { // un-initialized or cleared; find next
t = _parser.nextToken();
// If EOF, no more
if (t == null) {
_parser.close();
return false;
}
// And similarly if we hit END_ARRAY; except that we won't close parser
if (t == JsonToken.END_ARRAY) {
return false;
}
}
return true;
}
public T nextValue() throws IOException {
T result = _deserializer.deserialize(_parser, _context);
// Need to consume the token too
_parser.clearCurrentToken();
return result;
}
}