Package org.apache.calcite.schema.impl

Class ReflectiveFunctionBase

java.lang.Object

org.apache.calcite.schema.impl.ReflectiveFunctionBase

All Implemented Interfaces:

Function

Direct Known Subclasses:

ReflectiveSchema.MethodTableMacro, ScalarFunctionImpl, TableFunctionImpl, TableMacroImpl

public abstract class ReflectiveFunctionBase
extends java.lang.Object
implements Function

Implementation of a function that is based on a method. This class mainly solves conversion of method parameter types to List<FunctionParameter> form.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ReflectiveFunctionBase.ParameterListBuilder	Helps build lists of FunctionParameter.

Field Summary

Fields

Modifier and Type	Field	Description
java.lang.reflect.Method	method	Method that implements the function.
java.util.List<FunctionParameter>	parameters	Types of parameter for the function call.

Constructor Summary

Constructors

Constructor	Description
ReflectiveFunctionBase(java.lang.reflect.Method method)	ReflectiveFunctionBase constructor

Method Summary

Modifier and Type	Method	Description
static ReflectiveFunctionBase.ParameterListBuilder	builder()	Creates a ParameterListBuilder.
(package private) static boolean	classHasPublicZeroArgsConstructor(java.lang.Class<?> clazz)	Verifies if given class has public constructor with zero arguments.
(package private) static java.lang.reflect.Method	findMethod(java.lang.Class<?> clazz, java.lang.String name)	Finds a method in a given class by name.
java.util.List<FunctionParameter>	getParameters()	Returns the parameters of this function.

Methods inherited from class java.lang.Object

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

Field Detail

method

public final java.lang.reflect.Method method

Method that implements the function.

parameters

public final java.util.List<FunctionParameter> parameters

Types of parameter for the function call.

Constructor Detail

ReflectiveFunctionBase

public ReflectiveFunctionBase(java.lang.reflect.Method method)

ReflectiveFunctionBase constructor

Parameters:

method - method that is used to get type information from

Method Detail

getParameters

public java.util.List<FunctionParameter> getParameters()

Returns the parameters of this function.

Specified by:

getParameters in interface Function

Returns:

Parameters; never null

classHasPublicZeroArgsConstructor

static boolean classHasPublicZeroArgsConstructor(java.lang.Class<?> clazz)

Verifies if given class has public constructor with zero arguments.

Parameters:

clazz - class to verify

Returns:

true if given class has public constructor with zero arguments

findMethod

static java.lang.reflect.Method findMethod(java.lang.Class<?> clazz,
                                           java.lang.String name)

Finds a method in a given class by name.

Parameters:

clazz - class to search method in

name - name of the method to find

Returns:

the first method with matching name or null when no method found

builder

public static ReflectiveFunctionBase.ParameterListBuilder builder()

Creates a ParameterListBuilder.