org.apache.druid.java.util.common.parsers

Class JSONPathParser

java.lang.Object

org.apache.druid.java.util.common.parsers.JSONPathParser

All Implemented Interfaces:

Parser<String,Object>

public class JSONPathParser
extends Object
implements Parser<String,Object>

JSON parser class that uses the JsonPath library to access fields via path expressions.

Constructor Summary

Constructors

Constructor and Description
JSONPathParser(JSONPathSpec flattenSpec, com.fasterxml.jackson.databind.ObjectMapper mapper, boolean keepNullColumns) Constructor

Method Summary

Modifier and Type	Method and Description
List<String>	getFieldNames() Returns the fieldNames that we expect to see in parsed Maps, if known, or null otherwise.
Map<String,Object>	parseToMap(String input) Parse a String into a Map.
void	setFieldNames(Iterable<String> fieldNames) Set the fieldNames that you expect to see in parsed Maps.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.java.util.common.parsers.Parser

startFileFromBeginning

Constructor Detail

JSONPathParser

public JSONPathParser(JSONPathSpec flattenSpec,
                      com.fasterxml.jackson.databind.ObjectMapper mapper,
                      boolean keepNullColumns)

Constructor

Parameters:

flattenSpec - Provide a path spec for flattening and field discovery.

mapper - Optionally provide an ObjectMapper, used by the parser for reading the input JSON.

Method Detail

getFieldNames

public List<String> getFieldNames()

Description copied from interface: Parser

Returns the fieldNames that we expect to see in parsed Maps, if known, or null otherwise. Deprecated; Parsers should not, in general, be expected to know what fields they will return.

Specified by:

getFieldNames in interface Parser<String,Object>

setFieldNames

public void setFieldNames(Iterable<String> fieldNames)

Description copied from interface: Parser

Set the fieldNames that you expect to see in parsed Maps. Deprecated; Parsers should not, in general, be expected to know what fields they will return. Some individual types of parsers do need to know (like a TSV parser) and those parsers have their own way of setting field names.

Specified by:

setFieldNames in interface Parser<String,Object>

parseToMap

public Map<String,Object> parseToMap(String input)

Description copied from interface: Parser

Parse a String into a Map. The result can be null which means the given input string will be ignored.

Specified by:

parseToMap in interface Parser<String,Object>

Parameters:

input - JSON string. The root must be a JSON object, not an array. e.g., {"valid": "true"} and {"valid":[1,2,3]} are supported but [{"invalid": "true"}] and [1,2,3] are not.

Returns:

A map of field names and values