Package org.apache.druid.segment.nested

Class NestedPathFinder

java.lang.Object

org.apache.druid.segment.nested.NestedPathFinder

public class NestedPathFinder
extends Object

Field Summary

Fields

Modifier and Type	Field	Description
static final String	JQ_PATH_ROOT
static final String	JSON_PATH_ROOT
static final byte	VERSION

Constructor Summary

Constructors

Constructor	Description
NestedPathFinder()

Method Summary

Modifier and Type	Method	Description
static Object	find(Object data, List<NestedPathPart> path)	Dig through a thing to find stuff
static Object[]	findKeys(Object data, List<NestedPathPart> path)	find the list of 'keys' at some path.
static List<NestedPathPart>	parseBadJsonPath(String path)	Split a JSONPath expression into a series of NestedPathPart representing the structure of the path expression.
static List<NestedPathPart>	parseJqPath(String path)	split a jq path into a series of extractors to find things in stuff
static List<NestedPathPart>	parseJsonPath(String path)	Split a JSONPath expression into a series of NestedPathPart representing the structure of the path expression.
static String	toNormalizedJqPath(List<NestedPathPart> paths)	Given a list of part finders, convert it to a "normalized" 'jq' path format that is consistent with how StructuredDataProcessor constructs field path names
static String	toNormalizedJsonPath(List<NestedPathPart> paths)

Methods inherited from class java.lang.Object

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

Field Details

VERSION

public static final byte VERSION

See Also:

• Constant Field Values

JSON_PATH_ROOT

public static final String JSON_PATH_ROOT

See Also:

• Constant Field Values

JQ_PATH_ROOT

public static final String JQ_PATH_ROOT

See Also:

• Constant Field Values

Constructor Details

NestedPathFinder

public NestedPathFinder()

Method Details

find

@Nullable
public static Object find(@Nullable
 Object data,
 List<NestedPathPart> path)

Dig through a thing to find stuff

findKeys

@Nullable
public static Object[] findKeys(@Nullable
 Object data,
 List<NestedPathPart> path)

find the list of 'keys' at some path. - if the thing at a path is an object (map), return the fields - if the thing at a path is an array (list or array), return the 0 based element numbers - if the thing is a simple value, return null

toNormalizedJsonPath

public static String toNormalizedJsonPath(List<NestedPathPart> paths)

parseJsonPath

public static List<NestedPathPart> parseJsonPath(@Nullable
 String path)

Split a JSONPath expression into a series of NestedPathPart representing the structure of the path expression. This allows using with find(Object, List) in order to extract values from json objects represented as java Map and List.

parseBadJsonPath

public static List<NestedPathPart> parseBadJsonPath(@Nullable
 String path)

Split a JSONPath expression into a series of NestedPathPart representing the structure of the path expression. This method is a variant of parseJsonPath(String) which allows fixing up any illegal expressions encountered from a previously bugged version of toNormalizedJsonPath(List), which incorrectly created path expressions like '$..a' or '$.[0].a' when encountering empty fields instead of the correct '$[''].a' and '$[''][0].a'. This method should only be used for converting field dictionaries stored in columns to fix the incorrectly stored paths, and never for parsing user input expressions.

toNormalizedJqPath

public static String toNormalizedJqPath(List<NestedPathPart> paths)

Given a list of part finders, convert it to a "normalized" 'jq' path format that is consistent with how StructuredDataProcessor constructs field path names

parseJqPath

public static List<NestedPathPart> parseJqPath(@Nullable
 String path)

split a jq path into a series of extractors to find things in stuff