Package org.opennms.netmgt.flows.elastic

Class GPath<O>

java.lang.Object

org.opennms.netmgt.flows.elastic.GPath<O>

Type Parameters:

O - the selection result

public class GPath<O>
extends Object

Allows to select values from GSON documents The eval method returns the selection result given a root JsonElement. GPath instances can be built either

1. by starting from the last select step and adding the preceding selection steps in a fluent interface like manner (e.g. the GPath string().field("name") accesses the "name" field of a GSON document) or
2. by using nested methods calls (e.g. the nested method calls field("name", string()) construct the same GSON path).

Constructor Summary

Constructors

Constructor	Description
GPath(java.util.function.Function<com.google.gson.JsonElement,O> eval)

Method Summary

Modifier and Type	Method	Description
static GPath<com.google.gson.JsonElement>	any()
static GPath<com.google.gson.JsonArray>	array()
GPath<List<O>>	array(String name)
static <X> GPath<List<X>>	array(String name, GPath<X> path)
static GPath<Double>	dbl()
O	eval(com.google.gson.JsonElement in)	Returns the selection result given the root JsonElement.
GPath<O>	field(String name)
GPath<O>	field(String name, String altName)
static <X> GPath<X>	field(String name, String altName, GPath<X> path)
static <X> GPath<X>	field(String name, GPath<X> path)
static GPath<Integer>	integer()
<X> GPath<X>	map(java.util.function.Function<O,X> f)
static GPath<com.google.gson.JsonObject>	object()
static GPath<String>	string()

Methods inherited from class java.lang.Object

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

Constructor Detail

GPath

public GPath(java.util.function.Function<com.google.gson.JsonElement,O> eval)

Method Detail

string

public static GPath<String> string()

dbl

public static GPath<Double> dbl()

integer

public static GPath<Integer> integer()

any

public static GPath<com.google.gson.JsonElement> any()

object

public static GPath<com.google.gson.JsonObject> object()

array

public static GPath<com.google.gson.JsonArray> array()

field

public static <X> GPath<X> field(String name,
                                 GPath<X> path)

field

public static <X> GPath<X> field(String name,
                                 String altName,
                                 GPath<X> path)

array

public static <X> GPath<List<X>> array(String name,
                                       GPath<X> path)

field

public GPath<O> field(String name)

field

public GPath<O> field(String name,
                      String altName)

array

public GPath<List<O>> array(String name)

map

public <X> GPath<X> map(java.util.function.Function<O,X> f)

eval

public O eval(com.google.gson.JsonElement in)

Returns the selection result given the root JsonElement.

Parameters:

in - the root element the evaluation is base on.

Returns:

in case that the GPath selects non-existing fields null is returned.