io.druid.java.util.common.parsers

Class JSONPathParser

java.lang.Object

io.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.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	JSONPathParser.FieldSpec Specifies a field to be added to the parsed object Map, using JsonPath notation.
static class	JSONPathParser.FieldType Specifies access behavior for a field.

Constructor Summary

Constructors

Constructor and Description
JSONPathParser(List<JSONPathParser.FieldSpec> fieldSpecs, boolean useFieldDiscovery, com.fasterxml.jackson.databind.ObjectMapper mapper) 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>	parse(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

Constructor Detail

JSONPathParser

public JSONPathParser(List<JSONPathParser.FieldSpec> fieldSpecs,
                      boolean useFieldDiscovery,
                      com.fasterxml.jackson.databind.ObjectMapper mapper)

Constructor

Parameters:

fieldSpecs - List of field specifications.

useFieldDiscovery - If true, automatically add root fields seen in the JSON document to the parsed object Map. Only fields that contain a singular value or flat list (list containing no subobjects or lists) are automatically added.

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>

parse

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

Description copied from interface: Parser

Parse a String into a Map.

Specified by:

parse 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