org.apache.drill.exec.store.easy.json.parser

Class RootParser

java.lang.Object

org.apache.drill.exec.store.easy.json.parser.RootParser

Direct Known Subclasses:

RootParser.EmbeddedArrayParser, RootParser.EmbeddedObjectParser, RootParser.RootArrayParser, RootParser.RootObjectParser

public abstract class RootParser
extends Object

The root parsers are special: they must detect EOF. Drill supports top-level objects either enclosed in an array (which forms legal JSON), or as the jsonlines format, restricted to a list of objects (but not scalars or arrays.) Although jsonlines requires newline separators between objects, this parser allows any amount of whitespace, including none.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RootParser.EmbeddedArrayParser Parser for data embedded within a message structure which is encoded as an array of objects.
static class	RootParser.EmbeddedObjectParser Parser for data embedded within a message structure which is encoded as a single JSON object.
static class	RootParser.RootArrayParser Parser for a compliant JSON data set which consists of an array at the top level, where each element of the array is a JSON object that represents a data record.
static class	RootParser.RootObjectParser Parser for a jsonlines-style data set which consists of a series of objects.

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.slf4j.Logger	logger
protected ObjectParser	rootObject

Constructor Summary

Constructors

Constructor and Description
RootParser(JsonStructureParser structParser)

Method Summary

Modifier and Type	Method and Description
protected ErrorFactory	errorFactory()
abstract boolean	parseRoot(TokenIterator tokenizer) Parse one data object.
protected boolean	parseRootObject(com.fasterxml.jackson.core.JsonToken token, TokenIterator tokenizer) Parse one data object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

logger

protected static final org.slf4j.Logger logger

rootObject

protected final ObjectParser rootObject

Constructor Detail

RootParser

public RootParser(JsonStructureParser structParser)

Method Detail

parseRoot

public abstract boolean parseRoot(TokenIterator tokenizer)

Parse one data object. This is the "root" object which may contain nested objects. Overridden to handle different end-of-data indicators for different contexts.

Returns:

true if an object was found, false if the end of data was reached.

parseRootObject

protected boolean parseRootObject(com.fasterxml.jackson.core.JsonToken token,
                                  TokenIterator tokenizer)

Parse one data object. This is the "root" object which may contain nested objects. Called when the outer parser detects a start object token for a data object.

Returns:

true if an object was found, false if the end of data was reached.

errorFactory

protected ErrorFactory errorFactory()