org.datanucleus.query.compiler

Class JavaQueryCompiler

java.lang.Object

org.datanucleus.query.compiler.JavaQueryCompiler

All Implemented Interfaces:

SymbolResolver

Direct Known Subclasses:

JDOQLCompiler, JPQLCompiler

public abstract class JavaQueryCompiler
extends Object
implements SymbolResolver

Typical implementation of a compiler for a java-based query language. The constructor takes in the components of the query, and the method compile() compiles it returning the compiled query, for use elsewhere.

Each "Expression" is effectively a tree of Expressions. You can navigate through each expression based on their type. For example, a DyadicExpression has a "left" and "right" and an operator between them. The left could also be a DyadicExpression, so you would navigate to its left/right components etc etc.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	candidateAlias Alias for the primary candidate.
protected String	candidateAliasOrig Default candidate alias in use (only set when in a subquery and the same as the outer query).
protected Class	candidateClass Primary candidate class (if defined).
protected Collection	candidates
protected boolean	caseSensitiveAliases
protected ClassLoaderResolver	clr
protected String	filter
protected String	from
protected String	grouping
protected String	having
protected Imports	imports
protected static Localiser	LOCALISER Localisation utility for output messages
protected MetaDataManager	metaDataManager
protected String	ordering
protected String	parameters
protected int	parameterSubstitutionNumber
protected Map<Object,String>	parameterSubtitutionMap
protected JavaQueryCompiler	parentCompiler
protected Parser	parser Parser specific to the type of query being compiled.
protected Map<String,String>	queryMethodAliasByPrefix
protected String	result
protected SymbolTable	symtbl Compiled Symbol Table.
protected String	update
protected String	variables

Constructor Summary

Constructors

Constructor and Description
JavaQueryCompiler(MetaDataManager metaDataManager, ClassLoaderResolver clr, String from, Class candidateClass, Collection candidates, String filter, Imports imports, String ordering, String result, String grouping, String having, String params, String variables, String update)

Method Summary

Methods

Modifier and Type	Method and Description
abstract QueryCompilation	compile(Map parameters, Map subqueryMap) Method to compile the query.
void	compileCandidatesParametersVariables(Map parameters) Compile the candidates, variables and parameters.
Expression	compileFilter() Compile the filter and return the compiled expression.
protected Expression[]	compileFrom() Method to compile the "from" clause (if present for the query language).
Expression[]	compileGrouping()
Expression	compileHaving()
Expression[]	compileOrdering()
Expression[]	compileResult()
Expression[]	compileUpdate()
abstract String	getLanguage() Accessor for the query language name.
Class	getPrimaryClass() Accessor for the candidate class of the query.
Class	getType(List tuples)
protected abstract boolean	isKeyword(String name) Method to return if the supplied name is a keyword.
Class	resolveClass(String className) Method to perform a lookup of the class name from the input name.
void	setLinkToParentQuery(JavaQueryCompiler parentCompiler, Map paramSubstitutionMap) Method to set the linkage to the parent query.
protected void	swapCandidateAliasNodeName(Node node) Convenience method that takes the input node and if it is set to the original candidate alias then swaps the value to the candidate alias.
protected Node	swapSubqueryParameters(Node node) Convenience method that takes the input node if it is a parameter node swaps the node to be

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.datanucleus.query.symbol.SymbolResolver

caseSensitiveSymbolNames, supportsImplicitVariables

Field Detail

LOCALISER

protected static final Localiser LOCALISER

Localisation utility for output messages

parentCompiler

protected JavaQueryCompiler parentCompiler

parameterSubtitutionMap

protected Map<Object,String> parameterSubtitutionMap

parameterSubstitutionNumber

protected int parameterSubstitutionNumber

metaDataManager

protected final MetaDataManager metaDataManager

clr

protected final ClassLoaderResolver clr

caseSensitiveAliases

protected boolean caseSensitiveAliases

candidateClass

protected Class candidateClass

Primary candidate class (if defined).

candidateAlias

protected String candidateAlias

Alias for the primary candidate. Default to "this" (JDOQL) but can be set.

candidateAliasOrig

protected String candidateAliasOrig

Default candidate alias in use (only set when in a subquery and the same as the outer query).

from

protected String from

candidates

protected Collection candidates

update

protected String update

filter

protected String filter

ordering

protected String ordering

parameters

protected String parameters

variables

protected String variables

grouping

protected String grouping

having

protected String having

result

protected String result

imports

protected Imports imports

symtbl

protected SymbolTable symtbl

Compiled Symbol Table.

parser

protected Parser parser

Parser specific to the type of query being compiled.

queryMethodAliasByPrefix

protected Map<String,String> queryMethodAliasByPrefix

Constructor Detail

JavaQueryCompiler

public JavaQueryCompiler(MetaDataManager metaDataManager,
                 ClassLoaderResolver clr,
                 String from,
                 Class candidateClass,
                 Collection candidates,
                 String filter,
                 Imports imports,
                 String ordering,
                 String result,
                 String grouping,
                 String having,
                 String params,
                 String variables,
                 String update)

Method Detail

getLanguage

public abstract String getLanguage()

Accessor for the query language name.

Returns:

Name of the query language.

setLinkToParentQuery

public void setLinkToParentQuery(JavaQueryCompiler parentCompiler,
                        Map paramSubstitutionMap)

Method to set the linkage to the parent query.

Parameters:

parentCompiler - Compiler for the parent query

paramSubstitutionMap - Map of parameters in this subquery and what they are in the parent query.

compile

public abstract QueryCompilation compile(Map parameters,
                       Map subqueryMap)

Method to compile the query.

Parameters:

parameters - The parameter values keyed by name.

subqueryMap - Map of subqueries keyed by the subquery name

Returns:

The query compilation

compileCandidatesParametersVariables

public void compileCandidatesParametersVariables(Map parameters)

Compile the candidates, variables and parameters.

Parameters:

parameters - Map of parameter values keyed by their name

compileFrom

protected Expression[] compileFrom()

Method to compile the "from" clause (if present for the query language).

compileUpdate

public Expression[] compileUpdate()

compileFilter

public Expression compileFilter()

Compile the filter and return the compiled expression.

Returns:

The compiled expression

swapCandidateAliasNodeName

protected void swapCandidateAliasNodeName(Node node)

Convenience method that takes the input node and if it is set to the original candidate alias then swaps the value to the candidate alias. This is for the situation where we have a subquery which had no alias defined so defaults to "this" (the same as the outer query), so we change the subquery alias from "this" to "sub_this".

Parameters:

node - The node to process

swapSubqueryParameters

protected Node swapSubqueryParameters(Node node)

Convenience method that takes the input node if it is a parameter node swaps the node to be

Parameters:

node - The node to process

compileResult

public Expression[] compileResult()

compileGrouping

public Expression[] compileGrouping()

compileHaving

public Expression compileHaving()

compileOrdering

public Expression[] compileOrdering()

getPrimaryClass

public Class getPrimaryClass()

Description copied from interface: SymbolResolver

Accessor for the candidate class of the query.

Specified by:

getPrimaryClass in interface SymbolResolver

Returns:

The candidate class

resolveClass

public Class resolveClass(String className)

Method to perform a lookup of the class name from the input name. Makes use of the query "imports" and the lookup to "entity name".

Specified by:

resolveClass in interface SymbolResolver

Parameters:

className - Name of the class

Returns:

The class corresponding to this name

Throws:

ClassNotResolvedException - thrown if not resolvable using imports or entity name

getType

public Class getType(List tuples)

Specified by:

getType in interface SymbolResolver

isKeyword

protected abstract boolean isKeyword(String name)

Method to return if the supplied name is a keyword. Keywords can only appear at particular places in a query so we need to detect for valid queries.

Parameters:

name - The name

Returns:

Whether it is a keyword