org.outerj.grouping.functions
Class SSumFunction
java.lang.Object
org.outerj.expression.AbstractExpression
org.outerj.grouping.functions.SSumFunction
- All Implemented Interfaces:
- Expression
- public class SSumFunction
- extends AbstractExpression
A function for usage in Expressions. SSum is short for "Summary Sum", it calculates
a sum accross the current summary. This function should be used in conjunction with
the Column function.
Method Summary |
void |
check()
Check if the expression's structure is OK. |
java.lang.Object |
evaluate(ExpressionContext context)
Evaluates this expression and returns the result of that evaluation. |
java.lang.String |
getDescription()
Returns a description of this expression that will be shown to the user
in error messages. |
java.lang.Class |
getResultType()
Returns the class of the the type of object that this expression will return. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
SSumFunction
public SSumFunction()
evaluate
public java.lang.Object evaluate(ExpressionContext context)
throws ExpressionException
- Description copied from interface:
Expression
- Evaluates this expression and returns the result of that evaluation.
- Throws:
ExpressionException
check
public void check()
throws ExpressionException
- Description copied from interface:
Expression
- Check if the expression's structure is OK.
If everything is ok, this method should just return.
- Specified by:
check
in interface Expression
- Overrides:
check
in class AbstractExpression
- Throws:
ExpressionException
getResultType
public java.lang.Class getResultType()
- Description copied from interface:
Expression
- Returns the class of the the type of object that this expression will return.
This allows to check the correctness of functions at compile-time.
If unknown, this may return
null
.
getDescription
public java.lang.String getDescription()
- Description copied from interface:
Expression
- Returns a description of this expression that will be shown to the user
in error messages.