https://github.com/jayway/JsonPath: Java port of Stefan Goessner JsonPath.
  • Kalle Stenflo 
package com.jayway.jsonpath.internal.function;

import com.jayway.jsonpath.internal.EvaluationContext;
import com.jayway.jsonpath.internal.PathRef;

import java.util.List;


Defines the pattern by which a function can be executed over the result set in the particular path
being grabbed.  The Function's input is the content of the data from the json path selector and its output
is defined via the functions behavior.  Thus transformations in types can take place.  Additionally, functions
can accept multiple selectors in order to produce their output.
Created by matt@mjgreenwood.net on 6/26/15.

/**
 * Defines the pattern by which a function can be executed over the result set in the particular path
 * being grabbed.  The Function's input is the content of the data from the json path selector and its output
 * is defined via the functions behavior.  Thus transformations in types can take place.  Additionally, functions
 * can accept multiple selectors in order to produce their output.
 *
 * Created by matt@mjgreenwood.net on 6/26/15.
 */
public interface PathFunction {

    
Invoke the function and output a JSON object (or scalar) value which will be the result of executing the path

Params:
  • currentPath – 
     The current path location inclusive of the function name
  • parent – 
     The path location above the current function
  • model – 
     The JSON model as input to this particular function
  • ctx – 
     Eval context, state bag used as the path is traversed, maintains the result of executing
  • parameters – 
Returns:result
/**
     * Invoke the function and output a JSON object (or scalar) value which will be the result of executing the path
     *
     * @param currentPath
     *      The current path location inclusive of the function name
     * @param parent
     *      The path location above the current function
     *
     * @param model
     *      The JSON model as input to this particular function
     *
     * @param ctx
     *      Eval context, state bag used as the path is traversed, maintains the result of executing
     *
     * @param parameters
     * @return result
     */
    Object invoke(String currentPath, PathRef parent, Object model, EvaluationContext ctx, List<Parameter> parameters);
}