com.elegantj.data.comp.computedfield
Class ExpressionExecutor

java.lang.Object
  com.elegantj.data.comp.computedfield.ExpressionExecutor

public class ExpressionExecutor

extends java.lang.Object

The ExpressionExecutor is used to build and to execute the expression. It can execute the arithmetic expression, it can also execute the database related expression if the MethodsClass is provided.

Constructor Summary

ExpressionExecutor()

ExpressionExecutor(MethodsClass methodsClass)
Creates an ExpressionExecutor with specified MethodsClass.

Method Summary

java.lang.Object	executeExp() Executes the expression.
java.lang.Object	executeExp(java.lang.String expression) Executes the given expression.
java.lang.String	getExpression() Returns the expression to be executed
FunctionTable	getFunctionTable() Returns the function table
Parser	getParser() Returns the expression parser
java.lang.String[]	getPredefinedTokens() Returns the predefined tokens, which are valid to use in the expression
Scanner	getScanner() Returns the expression scanner
SymbolTable	getSymbolTable() Returns the symbol table
void	setColumns(java.util.Vector columns, java.util.Vector values) Sets the column names and related values
void	setExpression(java.lang.String expression) Sets the expression to be executed
boolean	verifyExp() Checks the verification of the expression.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpressionExecutor

public ExpressionExecutor()

ExpressionExecutor

public ExpressionExecutor(MethodsClass methodsClass)

Creates an ExpressionExecutor with specified MethodsClass.

Parameters:

methodsClass - the MethodsClass which contains the methods to be invoked by executor to execute the expression, default null

Method Detail

setExpression

public void setExpression(java.lang.String expression)

Sets the expression to be executed

Parameters:

expression - the expression string

setColumns

public void setColumns(java.util.Vector columns,
                       java.util.Vector values)

Sets the column names and related values

Parameters:

columns - the vector of the column names

values - the vector of the column values

verifyExp

public boolean verifyExp()

Checks the verification of the expression.

Returns:

true if the expression is valid, false otherwise.

executeExp

public java.lang.Object executeExp()

Executes the expression.

Returns:

the result of the execution

executeExp

public java.lang.Object executeExp(java.lang.String expression)

Executes the given expression.

Parameters:

expression - the expression to be executed

Returns:

the result of the execution

getParser

public Parser getParser()

Returns the expression parser

Returns:

the parser

getScanner

public Scanner getScanner()

Returns the expression scanner

Returns:

the scanner

getSymbolTable

public SymbolTable getSymbolTable()

Returns the symbol table

Returns:

the symbol table

getFunctionTable

public FunctionTable getFunctionTable()

Returns the function table

Returns:

the function table

getExpression

public java.lang.String getExpression()

Returns the expression to be executed

Returns:

the expression string

getPredefinedTokens

public java.lang.String[] getPredefinedTokens()

Returns the predefined tokens, which are valid to use in the expression

Returns:

the array of the valid tokens string