de.unidu.is.expressions
Class AbstractExpression

java.lang.Object
  de.unidu.is.expressions.AbstractExpression

All Implemented Interfaces:

Expression

Direct Known Subclasses:

Arg2Expression, ArgNExpression, BinaryStandardFunctionExpression, DBColumnExpression, DBProbExpression, FunctionExpression, LiteralExpression, PlainExpression, ProbExpression, StringExpression, VariableExpression

public class AbstractExpression

extends java.lang.Object

implements Expression

An abstract class for expressions.

Since:

2003-11-08

Version:

$Revision: 1.4 $, $Date: 2005/02/21 17:29:18 $

Author:

Henrik Nottelmann

Constructor Summary

AbstractExpression()

Method Summary

java.lang.String	getSQLTemplate() Returns a string representation for this expression which can be used as a template in an SQL statement.
Expression	substitute(java.util.Map binding) Performs an substitution for variables, e.g. for each key variable in the specified binding, all occurences of ${key} are replaced by the corresponding value in the map.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractExpression

public AbstractExpression()

Method Detail

substitute

public Expression substitute(java.util.Map binding)

Performs an substitution for variables, e.g. for each key variable in the specified binding, all occurences of ${key} are replaced by the corresponding value in the map.

Here, the same untouched expression is returned. Subclasses can overwrite this behaviour.

Specified by:

substitute in interface Expression

Parameters:

binding - variable binding

Returns:

expression after substitution

getSQLTemplate

public java.lang.String getSQLTemplate()

Returns a string representation for this expression which can be used as a template in an SQL statement.

Specified by:

getSQLTemplate in interface Expression

Returns:

template for SQL statements