org.geotools.filter

Class FunctionFinder

Object

FunctionFinder

public class FunctionFinder
extends Object

Isolate function lookup code from Factory implementation(s).

This is done to look for two things:

• org.geotools.filter.Function
• org.opengis.filter.expression.Function

This is done as a proper utility class that accepts Hints.

Author:

Jody Garnett

Constructor Summary

Constructors

Constructor and Description
FunctionFinder(Hints hints)

Method Summary

Modifier and Type	Method and Description
Function	findFunction(Name name)
Function	findFunction(Name name, List<Expression> parameters) Look up a function for the provided name.
Function	findFunction(Name name, List<Expression> parameters, Literal fallback) Look up a function for the provided name, may return a FallbackFunction if an implementation could not be found.
Function	findFunction(String name)
Function	findFunction(String name, List<Expression> parameters) Look up a function for the provided name.
Function	findFunction(String name, List<Expression> parameters, Literal fallback) Look up a function for the provided name, may return a FallbackFunction if an implementation could not be found.
FunctionName	findFunctionDescription(Name name) Lookup the FunctionName description.
FunctionName	findFunctionDescription(String name) Lookup the FunctionName description.
List<FunctionName>	getAllFunctionDescriptions() Return a List of FunctionName's describing the functions currently available.

Methods inherited from class Object

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

Constructor Detail

FunctionFinder

public FunctionFinder(Hints hints)

Method Detail

getAllFunctionDescriptions

public List<FunctionName> getAllFunctionDescriptions()

Return a List of FunctionName's describing the functions currently available.

Returns:

List describing available functions

findFunctionDescription

public FunctionName findFunctionDescription(String name)

Lookup the FunctionName description.

Parameters:

name - Function name; this will need to be an exact match

Returns:

FunctioName description, or null if function is not available

findFunctionDescription

public FunctionName findFunctionDescription(Name name)

Lookup the FunctionName description.

Parameters:

name - Function name; this will need to be an exact match

Returns:

FunctioName description, or null if function is not available

findFunction

public Function findFunction(String name)

findFunction

public Function findFunction(Name name)

findFunction

public Function findFunction(String name,
                             List<Expression> parameters)

Look up a function for the provided name.

Parameters:

name - Function name; this will need to be an exact match

parameters - Set of parameters required

Returns:

Generated function

Throws:

a - RuntimeException if an implementation for name could not be found

findFunction

public Function findFunction(Name name,
                             List<Expression> parameters)

Look up a function for the provided name.

Parameters:

name - Function name; this will need to be an exact match

parameters - Set of parameters required

Returns:

Generated function

Throws:

a - RuntimeException if an implementation for name could not be found

findFunction

public Function findFunction(String name,
                             List<Expression> parameters,
                             Literal fallback)

Look up a function for the provided name, may return a FallbackFunction if an implementation could not be found.

You can create a function to represent an SQL function or a function hosted on an external service; the fallback value will be used if you evulate by a Java implementation on the classpath.

Parameters:

name - Function name; this will need to be an exact match

parameters - Set of Expressions to use as function parameters

fallback - Literal to use if an implementation could not be found

Returns:

Function for the provided name, may be a FallbackFunction if an implementation could not be found

findFunction

public Function findFunction(Name name,
                             List<Expression> parameters,
                             Literal fallback)

Look up a function for the provided name, may return a FallbackFunction if an implementation could not be found.

You can create a function to represent an SQL function or a function hosted on an external service; the fallback value will be used if you evulate by a Java implementation on the classpath.

Parameters:

name - Function name; this will need to be an exact match

parameters - Set of Expressions to use as function parameters

fallback - Literal to use if an implementation could not be found

Returns:

Function for the provided name, may be a FallbackFunction if an implementation could not be found