org.apache.calcite.adapter.java

Class ReflectiveSchema

java.lang.Object

org.apache.calcite.schema.impl.AbstractSchema

org.apache.calcite.adapter.java.ReflectiveSchema

All Implemented Interfaces:

Schema

public class ReflectiveSchema
extends AbstractSchema

Implementation of Schema that exposes the public fields and methods in a Java object.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ReflectiveSchema.Factory Factory that creates a schema by instantiating an object and looking at its public fields.
private static class	ReflectiveSchema.FieldSelector Function that returns an array of a given object's field values.
private static class	ReflectiveSchema.FieldTable<T> Table based on a Java field.
private static class	ReflectiveSchema.MethodTableMacro Table macro based on a Java method.
private static class	ReflectiveSchema.ReflectiveTable Table that is implemented by reading from a Java object.

Nested classes/interfaces inherited from interface org.apache.calcite.schema.Schema

Schema.TableType

Field Summary

Fields

Modifier and Type	Field and Description
private Class	clazz
private com.google.common.collect.Multimap<String,Function>	functionMap
private Map<String,Table>	tableMap
private Object	target

Constructor Summary

Constructors

Constructor and Description
ReflectiveSchema(Object target) Creates a ReflectiveSchema.

Method Summary

Modifier and Type	Method and Description
private com.google.common.collect.Multimap<String,Function>	createFunctionMap()
private Map<String,Table>	createTableMap()
private <T> Table	fieldRelation(Field field) Returns a table based on a particular field of this schema.
private static Type	getElementType(Class clazz) Deduces the element type of a collection; same logic as toEnumerable(java.lang.Object)
protected com.google.common.collect.Multimap<String,Function>	getFunctionMultimap() Returns a multi-map of functions in this schema by name.
protected Map<String,Table>	getTableMap() Returns a map of tables in this schema by name.
Object	getTarget() Returns the wrapped object.
(package private) Expression	getTargetExpression(SchemaPlus parentSchema, String name) Returns an expression for the object wrapped by this schema (not the schema itself).
private static Enumerable	toEnumerable(Object o)
String	toString()

Methods inherited from class org.apache.calcite.schema.impl.AbstractSchema

getExpression, getFunctionNames, getFunctions, getSubSchema, getSubSchemaMap, getSubSchemaNames, getTable, getTableNames, isMutable, snapshot

Methods inherited from class java.lang.Object

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

Field Detail

clazz

private final Class clazz

target

private Object target

tableMap

private Map<String,Table> tableMap

functionMap

private com.google.common.collect.Multimap<String,Function> functionMap

Constructor Detail

ReflectiveSchema

public ReflectiveSchema(Object target)

Creates a ReflectiveSchema.

Parameters:

target - Object whose fields will be sub-objects of the schema

Method Detail

toString

public String toString()

Overrides:

toString in class Object

getTarget

public Object getTarget()

Returns the wrapped object.

May not appear to be used, but is used in generated code via BuiltInMethod.REFLECTIVE_SCHEMA_GET_TARGET.

getTableMap

protected Map<String,Table> getTableMap()

Description copied from class: AbstractSchema

Returns a map of tables in this schema by name.

The implementations of AbstractSchema.getTableNames() and AbstractSchema.getTable(String) depend on this map. The default implementation of this method returns the empty map. Override this method to change their behavior.

Overrides:

getTableMap in class AbstractSchema

Returns:

Map of tables in this schema by name

createTableMap

private Map<String,Table> createTableMap()

getFunctionMultimap

protected com.google.common.collect.Multimap<String,Function> getFunctionMultimap()

Description copied from class: AbstractSchema

Returns a multi-map of functions in this schema by name. It is a multi-map because functions are overloaded; there may be more than one function in a schema with a given name (as long as they have different parameter lists).

The implementations of AbstractSchema.getFunctionNames() and Schema.getFunctions(String) depend on this map. The default implementation of this method returns the empty multi-map. Override this method to change their behavior.

Overrides:

getFunctionMultimap in class AbstractSchema

Returns:

Multi-map of functions in this schema by name

createFunctionMap

private com.google.common.collect.Multimap<String,Function> createFunctionMap()

getTargetExpression

Expression getTargetExpression(SchemaPlus parentSchema,
                               String name)

Returns an expression for the object wrapped by this schema (not the schema itself).

fieldRelation

private <T> Table fieldRelation(Field field)

Returns a table based on a particular field of this schema. If the field is not of the right type to be a relation, returns null.

getElementType

private static Type getElementType(Class clazz)

Deduces the element type of a collection; same logic as toEnumerable(java.lang.Object)

toEnumerable

private static Enumerable toEnumerable(Object o)