uk.ac.starlink.vo

Class AdqlValidator

java.lang.Object

uk.ac.starlink.vo.AdqlValidator

public class AdqlValidator
extends Object

Handles validation of ADQL queries. In the current implementation the heavy lifting is done by Gregory Mantelet's ADQL parser.

Since:

3 Oct 2011

Author:

Mark Taylor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	AdqlValidator.ValidatorTable Defines table metadata for tables known to the validator.

Method Summary

Modifier and Type	Method and Description
static AdqlValidator	createValidator() Returns a basic validator instance.
static AdqlValidator	createValidator(AdqlValidator.ValidatorTable[] vtables) Returns a validator instance that knows about available tables.
static AdqlValidator	createValidator(AdqlValidator.ValidatorTable[] vtables, TapLanguage lang) Creates an instance given a set of table metadata and a TapLanguage description object.
String	fixup(String query) Attempts to fix common errors in a submitted query.
static void	main(String[] args) Tests parser.
void	setAdqlVersion(AdqlVersion version) Sets the version of ADQL against which this validator will check.
void	setAllowAnyUdf(boolean isAllowed) Configures whether the parser will allow undeclared functions.
void	validate(String query) Validates an ADQL string.

Methods inherited from class java.lang.Object

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

Method Detail

setAdqlVersion

public void setAdqlVersion(AdqlVersion version)

Sets the version of ADQL against which this validator will check.

Parameters:

version - ADQL version to use, or null for default

setAllowAnyUdf

public void setAllowAnyUdf(boolean isAllowed)

Configures whether the parser will allow undeclared functions.

Parameters:

isAllowed - true to allow undeclared functions, false to reject

validate

public void validate(String query)
              throws adql.parser.grammar.ParseException,
                     adql.parser.grammar.TokenMgrError

Validates an ADQL string. Any throwable returned hopefully includes useful information about the location and nature of the parse error, but that depends on the implementation.

Parameters:

query - ADQL query string

Throws:

adql.parser.grammar.ParseException - if the string is not valid ADQL

adql.parser.grammar.TokenMgrError - if something has gone wrong with the parsing

fixup

public String fixup(String query)

Attempts to fix common errors in a submitted query. If some changes can be made that would make the query more correct, the fixed query is returned. If no such changes can be made for whatever reason, null is returned.

Parameters:

query - input ADQL

Returns:

EITHER ADQL which resembles, but is not identical to, the input but which has a better chance of being correct; OR null

createValidator

public static AdqlValidator createValidator()

Returns a basic validator instance.

Returns:

new vanilla validator

createValidator

public static AdqlValidator createValidator(AdqlValidator.ValidatorTable[] vtables)

Returns a validator instance that knows about available tables.

Parameters:

vtables - table metadata for database to be checked against

Returns:

vanilla validator

createValidator

public static AdqlValidator createValidator(AdqlValidator.ValidatorTable[] vtables,
                                            TapLanguage lang)

Creates an instance given a set of table metadata and a TapLanguage description object. The language object's TapLanguageFeature map is examined to determine what UDFs and other optional features are supported. In the case that no features are declared, no restrictions are imposed.

Parameters:

vtables - table metadata

lang - language specifics

main

public static void main(String[] args)
                 throws adql.parser.grammar.ParseException,
                        IOException,
                        SAXException

Tests parser. Use -h for usage.

Throws:

adql.parser.grammar.ParseException

IOException

SAXException