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Copyright (c) 2007 Luis M. Pena - byteslooser@gmail.com

com.byteslooser.filters.parser.generic
Class FilterTextParser

java.lang.Object
  com.byteslooser.filters.parser.generic.FilterTextParser

All Implemented Interfaces:

IFilterTextParser

public class FilterTextParser
extends Object
implements IFilterTextParser

Specific implementation of the IFilterTextParser interface.

Own features of this implementation includes:

• Identifiers are case insensitive, unless there are multiple identifiers with the same case-variant text.
• It defines a predefined grammar, where the important characters are: & | ( ), and \ to escape them.
• It supports an extensable grammar to define the relational operators, based on the IRelationalOperandFactory interface.
• It supports an interface to define how to build not known types, the IRelationalOperandFactory interface.
• It supports the notion of null. The specific text associated to null is configurable.
• It support comparison between identifiers, but only if the operand is not string based and both identifiers have the same type (and is not String)
• A filter is composed by one or more subfilters, separated by & or | symbols, and possibly grouped using parenthesis.
• The smallest filter unit is composed by any string not including the previous symbols. It is interpreted as identifier-operand-expression, where the identifier and operand are optional. The grammar itself is unaware of the operators, working through a IRelationalOperandFactory that can identify any portion of string as an operand.
  Once an operand is identified, the previous part of the string is considered the identifier, and the rest, the expression
  Examples
  • (identifier > 34)
  • (> chain of characters)
  • (bravo)

Author:

Luis M Pena - byteslooser@gmail.com

Field Summary

static char	AND_CHAR
static char	CLOSE_PARENTHESIS_CHAR
static String	DEFAULT_NULL_STRING
static char	ESCAPE_CHAR
static char	OPEN_PARENTHESIS_CHAR
static char	OR_CHAR
static char	SPACE_CHAR

Fields inherited from interface com.byteslooser.filters.parser.IFilterTextParser

NO_FILTER_POSITION

Constructor Summary

FilterTextParser()
Simple contructor

FilterTextParser(IRelationalOperandFactory operandFactory)
Constructor defining a different set of relational operands

FilterTextParser(IRelationalOperandFactory operandFactory, ITypesFactory typesFactory)
Constructor defining a different set of relational operands and a type factory.

FilterTextParser(ITypesFactory typesFactory)
Constructor defining a specific type factory.

Method Summary

RowFilter	parseText(String exp, int defaultFilterPosition) Parses the text, using the given default identifier.
void	setComparator(Class<?> c, Comparator<?> cmp) Sets a specific comparator for a given class, that should override the default Compare algorithm for the given class.
void	setIdentifiers(List<IdentifierInfo> validIdentifiers) Defines the identifiers, and the types and indexes associated to them
void	setIgnoreCase(boolean ignore) Ignores case on the conditions associated to variables with String type
void	setNullString(String nullString) Sets the representation of the null case, null by default.
void	setTypeBuilder(Class<?> c, ITypeBuilder parser) Provides the ITypeBuilder to build non basic types

Methods inherited from class java.lang.Object

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

Field Detail

SPACE_CHAR

public static final char SPACE_CHAR

See Also:

Constant Field Values

ESCAPE_CHAR

public static final char ESCAPE_CHAR

See Also:

Constant Field Values

AND_CHAR

public static final char AND_CHAR

See Also:

Constant Field Values

OR_CHAR

public static final char OR_CHAR

See Also:

Constant Field Values

OPEN_PARENTHESIS_CHAR

public static final char OPEN_PARENTHESIS_CHAR

See Also:

Constant Field Values

CLOSE_PARENTHESIS_CHAR

public static final char CLOSE_PARENTHESIS_CHAR

See Also:

Constant Field Values

DEFAULT_NULL_STRING

public static final String DEFAULT_NULL_STRING

Constructor Detail

FilterTextParser

public FilterTextParser()

Simple contructor

FilterTextParser

public FilterTextParser(IRelationalOperandFactory operandFactory)

Constructor defining a different set of relational operands

Note that the main operands: ( ) & | are hardcoded in this class, cannot be modified in the passed factory

FilterTextParser

public FilterTextParser(ITypesFactory typesFactory)

Constructor defining a specific type factory.

FilterTextParser

public FilterTextParser(IRelationalOperandFactory operandFactory,
                        ITypesFactory typesFactory)

Constructor defining a different set of relational operands and a type factory.

Note that the main operands: ( ) & | are hardcoded in this class, cannot be modified in the passed factory

Method Detail

setIgnoreCase

public void setIgnoreCase(boolean ignore)

Description copied from interface: IFilterTextParser

Ignores case on the conditions associated to variables with String type

Specified by:

setIgnoreCase in interface IFilterTextParser

See Also:

IFilterTextParser.setIgnoreCase(boolean)

setIdentifiers

public void setIdentifiers(List<IdentifierInfo> validIdentifiers)

Description copied from interface: IFilterTextParser

Defines the identifiers, and the types and indexes associated to them

Specified by:

setIdentifiers in interface IFilterTextParser

See Also:

IFilterTextParser.setIdentifiers(List)

setComparator

public void setComparator(Class<?> c,
                          Comparator<?> cmp)

Sets a specific comparator for a given class, that should override the default Compare algorithm for the given class.

If the class is not Comparable, this method should be invoked to support any comparison operator.

setTypeBuilder

public void setTypeBuilder(Class<?> c,
                           ITypeBuilder parser)

Provides the ITypeBuilder to build non basic types

parseText

public RowFilter parseText(String exp,
                           int defaultFilterPosition)
                    throws FilterTextParsingException

Description copied from interface: IFilterTextParser

Parses the text, using the given default identifier.

If the parsed expression includes conditions that specify no identifier, the default identifier is used.

Default identifier can be IFilterTextParser.NO_FILTER_POSITION, if the expression must provide them specifically

A filter supporting the interface RowFilter receives an instance of type RowFilter.Entry that can enquiry to obtain the value at a specified index; the filter position is that given index, and corresponds, in the case of a table, to the column to which this editor is associated.

Specified by:

parseText in interface IFilterTextParser

Throws:

FilterTextParsingException

See Also:

IFilterTextParser.parseText(String, int)

setNullString

public void setNullString(String nullString)

Sets the representation of the null case, null by default.