java.lang.Object
- org.vedantatree.expressionoasis.expressions.ExpressionFactory

```
public class ExpressionFactory
extends Object
```
This is the expression factory which creates the expression for given expression token. It picks the mapping of tokens and corresponding expression classes from a XML file.

Since:

3.1

Field Summary

Fields
Modifier and Type	Field	Description
`static String`	`BINARY`	This is the binary expression type.
`static String`	`FUNCTION`	This is the function expression type.
`static String`	`OPERAND`	This is the operand expression type.
`static String`	`TRUE`	This is the true constant for absolute.
`static String`	`UNARY`	This is the unary expression type

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`void`	`addFunction(String functionName)`	Deprecated. No need to add function in ExpressionFactory, as it will always return FunctionExpression for all functions
`Expression`	`createExpression(String expressionToken, String type)`	Creates the expression object for given expression token and expression type
`static ExpressionFactory`	`getInstance()`	Gets the shared instance of Expression Factory

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - UNARY
```
public static final String UNARY
```
    This is the unary expression type
    
    See Also:
    
    Constant Field Values
  - BINARY
```
public static final String BINARY
```
    This is the binary expression type.
    
    See Also:
    
    Constant Field Values
  - FUNCTION
```
public static final String FUNCTION
```
    This is the function expression type.
    
    See Also:
    
    Constant Field Values
  - OPERAND
```
public static final String OPERAND
```
    This is the operand expression type.
    
    See Also:
    
    Constant Field Values
  - TRUE
```
public static final String TRUE
```
    This is the true constant for absolute.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - getInstance
```
public static ExpressionFactory getInstance()
```
    Gets the shared instance of Expression Factory
    
    Returns:
    
    Returns the shared instance
  - addFunction
```
public void addFunction(String functionName)
```
    Deprecated.
    No need to add function in ExpressionFactory, as it will always return FunctionExpression for all functions
    
    Adds a function expression for the specified function name
    
    Parameters:
    
    name - name of the function to add
  - createExpression
```
public Expression createExpression(String expressionToken,
                                   String type)
                            throws ExpressionEngineException
```
    Creates the expression object for given expression token and expression type
    
    Parameters:
    
    expressionToken - the token of expression
    
    type - the type of expression i.e. operand, operator etc
    
    Returns:
    
    the expression object
    
    Throws:
    
    ExpressionEngineException - if anything goes wrong

Class ExpressionFactory

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

UNARY

BINARY

FUNCTION

OPERAND

TRUE

Method Detail

getInstance

addFunction

createExpression