org.apache.commons.jexl2
Class JexlArithmetic

java.lang.Object
  extended by org.apache.commons.jexl2.JexlArithmetic

public class JexlArithmetic
extends java.lang.Object

Perform arithmetic.

All arithmetic operators (+, - , *, /, %) follow the same rules regarding their arguments.

  1. If both are null, result is 0
  2. If either is a floating point number, coerce both to Double and perform operation
  3. If both are BigInteger, treat as BigInteger and perform operation
  4. If either is a BigDecimal, coerce both to BigDecimal and and perform operation
  5. Else treat as BigInteger, perform operation and attempt to narrow result:
    1. if both arguments can be narrowed to Integer, narrow result to Integer
    2. if both arguments can be narrowed to Long, narrow result to Long
    3. Else return result as BigInteger

Since:
2.0

Field Summary
protected static java.math.BigDecimal BIGD_DOUBLE_MAX_VALUE
          Double.MAX_VALUE as BigDecimal.
protected static java.math.BigDecimal BIGD_DOUBLE_MIN_VALUE
          Double.MIN_VALUE as BigDecimal.
protected static java.math.BigInteger BIGI_LONG_MAX_VALUE
          Long.MAX_VALUE as BigInteger.
protected static java.math.BigInteger BIGI_LONG_MIN_VALUE
          Long.MIN_VALUE as BigInteger.
 
Constructor Summary
JexlArithmetic(boolean lenient)
          Creates a JexlArithmetic.
 
Method Summary
 java.lang.Object add(java.lang.Object left, java.lang.Object right)
          Add two values together.
protected  java.lang.Object controlNullNullOperands()
          The result of +,/,-,*,% when both operands are null.
protected  void controlNullOperand()
          Throw a NPE if arithmetic is strict.
 java.lang.Object divide(java.lang.Object left, java.lang.Object right)
          Divide the left value by the right.
 boolean equals(java.lang.Object left, java.lang.Object right)
          Test if left and right are equal.
 boolean greaterThan(java.lang.Object left, java.lang.Object right)
          Test if left > right.
 boolean greaterThanOrEqual(java.lang.Object left, java.lang.Object right)
          Test if left >= right.
protected  boolean isFloatingPoint(java.lang.Object o)
          Is Object a floating point number.
protected  boolean isFloatingPointNumber(java.lang.Object val)
          Test if the passed value is a floating point number, i.e.
protected  boolean isFloatingPointType(java.lang.Object left, java.lang.Object right)
          Test if either left or right are either a Float or Double.
 boolean isLenient()
          Checks whether this JexlArithmetic instance triggers errors during evaluation when null is used as an operand.
protected  boolean isNumberable(java.lang.Object o)
          Is Object a whole number.
 boolean lessThan(java.lang.Object left, java.lang.Object right)
          Test if left < right.
 boolean lessThanOrEqual(java.lang.Object left, java.lang.Object right)
          Test if left <= right.
 boolean matches(java.lang.Object left, java.lang.Object right)
          Test if left regexp matches right.
 java.lang.Object mod(java.lang.Object left, java.lang.Object right)
          left value mod right.
 java.lang.Object multiply(java.lang.Object left, java.lang.Object right)
          Multiply the left value by the right.
 java.lang.Number narrow(java.lang.Number original)
          Given a Number, return back the value using the smallest type the result will fit into.
protected  boolean narrowArguments(java.lang.Object[] args)
          Replace all numbers in an arguments array with the smallest type that will fit.
protected  java.lang.Object narrowArrayType(java.lang.Object[] untyped)
          Given an array of objects, attempt to type it more strictly.
protected  java.lang.Number narrowBigInteger(java.lang.Object lhs, java.lang.Object rhs, java.math.BigInteger bigi)
          Given a BigInteger, narrow it to an Integer or Long if it fits and the arguments class allow it.
 java.lang.Object subtract(java.lang.Object left, java.lang.Object right)
          Subtract the right value from the left.
 java.math.BigDecimal toBigDecimal(java.lang.Object val)
          Get a BigDecimal from the object passed.
 java.math.BigInteger toBigInteger(java.lang.Object val)
          Get a BigInteger from the object passed.
 boolean toBoolean(java.lang.Object val)
          Coerce to a boolean (not a java.lang.Boolean).
 double toDouble(java.lang.Object val)
          Coerce to a double.
 int toInteger(java.lang.Object val)
          Coerce to a int.
 long toLong(java.lang.Object val)
          Coerce to a long (not a java.lang.Long).
 java.lang.String toString(java.lang.Object val)
          Coerce to a string.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

BIGD_DOUBLE_MAX_VALUE

protected static final java.math.BigDecimal BIGD_DOUBLE_MAX_VALUE
Double.MAX_VALUE as BigDecimal.


BIGD_DOUBLE_MIN_VALUE

protected static final java.math.BigDecimal BIGD_DOUBLE_MIN_VALUE
Double.MIN_VALUE as BigDecimal.


BIGI_LONG_MAX_VALUE

protected static final java.math.BigInteger BIGI_LONG_MAX_VALUE
Long.MAX_VALUE as BigInteger.


BIGI_LONG_MIN_VALUE

protected static final java.math.BigInteger BIGI_LONG_MIN_VALUE
Long.MIN_VALUE as BigInteger.

Constructor Detail

JexlArithmetic

public JexlArithmetic(boolean lenient)
Creates a JexlArithmetic.

Parameters:
lenient - whether this arithmetic is lenient or strict
Method Detail

isLenient

public boolean isLenient()
Checks whether this JexlArithmetic instance triggers errors during evaluation when null is used as an operand.

Returns:
true if lenient, false if strict

controlNullNullOperands

protected java.lang.Object controlNullNullOperands()
The result of +,/,-,*,% when both operands are null.

Returns:
Integer(0) if lenient
Throws:
java.lang.NullPointerException - if strict

controlNullOperand

protected void controlNullOperand()
Throw a NPE if arithmetic is strict.

Throws:
java.lang.NullPointerException - if strict

isFloatingPointType

protected boolean isFloatingPointType(java.lang.Object left,
                                      java.lang.Object right)
Test if either left or right are either a Float or Double.

Parameters:
left - one object to test
right - the other
Returns:
the result of the test.

isFloatingPointNumber

protected boolean isFloatingPointNumber(java.lang.Object val)
Test if the passed value is a floating point number, i.e. a float, double or string with ( "." | "E" | "e").

Parameters:
val - the object to be tested
Returns:
true if it is, false otherwise.

isFloatingPoint

protected boolean isFloatingPoint(java.lang.Object o)
Is Object a floating point number.

Parameters:
o - Object to be analyzed.
Returns:
true if it is a Float or a Double.

isNumberable

protected boolean isNumberable(java.lang.Object o)
Is Object a whole number.

Parameters:
o - Object to be analyzed.
Returns:
true if Integer, Long, Byte, Short or Character.

narrowBigInteger

protected java.lang.Number narrowBigInteger(java.lang.Object lhs,
                                            java.lang.Object rhs,
                                            java.math.BigInteger bigi)
Given a BigInteger, narrow it to an Integer or Long if it fits and the arguments class allow it.

The rules are: if either arguments is a BigInteger, no narrowing will occur if either arguments is a Long, no narrowing to Integer will occur

Parameters:
lhs - the left hand side operand that lead to the bigi result
rhs - the right hand side operand that lead to the bigi result
bigi - the BigInteger to narrow
Returns:
an Integer or Long if narrowing is possible, the original BigInteger otherwise

narrowArrayType

protected java.lang.Object narrowArrayType(java.lang.Object[] untyped)
Given an array of objects, attempt to type it more strictly.

Parameters:
untyped - an untyped array
Returns:
the original array if the attempt to strictly type the array fails, a typed array otherwise

narrowArguments

protected boolean narrowArguments(java.lang.Object[] args)
Replace all numbers in an arguments array with the smallest type that will fit.

Parameters:
args - the argument array
Returns:
true if some arguments were narrowed and args array is modified, false if no narrowing occured and args array has not been modified

add

public java.lang.Object add(java.lang.Object left,
                            java.lang.Object right)
Add two values together.

If any numeric add fails on coercion to the appropriate type, treat as Strings and do concatenation.

Parameters:
left - first value
right - second value
Returns:
left + right.

divide

public java.lang.Object divide(java.lang.Object left,
                               java.lang.Object right)
Divide the left value by the right.

Parameters:
left - first value
right - second value
Returns:
left / right
Throws:
java.lang.ArithmeticException - if right == 0

mod

public java.lang.Object mod(java.lang.Object left,
                            java.lang.Object right)
left value mod right.

Parameters:
left - first value
right - second value
Returns:
left mod right
Throws:
java.lang.ArithmeticException - if right == 0.0

multiply

public java.lang.Object multiply(java.lang.Object left,
                                 java.lang.Object right)
Multiply the left value by the right.

Parameters:
left - first value
right - second value
Returns:
left * right.

subtract

public java.lang.Object subtract(java.lang.Object left,
                                 java.lang.Object right)
Subtract the right value from the left.

Parameters:
left - first value
right - second value
Returns:
left - right.

matches

public boolean matches(java.lang.Object left,
                       java.lang.Object right)
Test if left regexp matches right.

Parameters:
left - first value
right - second value
Returns:
test result.

equals

public boolean equals(java.lang.Object left,
                      java.lang.Object right)
Test if left and right are equal.

Parameters:
left - first value
right - second value
Returns:
test result.

lessThan

public boolean lessThan(java.lang.Object left,
                        java.lang.Object right)
Test if left < right.

Parameters:
left - first value
right - second value
Returns:
test result.

greaterThan

public boolean greaterThan(java.lang.Object left,
                           java.lang.Object right)
Test if left > right.

Parameters:
left - first value
right - second value
Returns:
test result.

lessThanOrEqual

public boolean lessThanOrEqual(java.lang.Object left,
                               java.lang.Object right)
Test if left <= right.

Parameters:
left - first value
right - second value
Returns:
test result.

greaterThanOrEqual

public boolean greaterThanOrEqual(java.lang.Object left,
                                  java.lang.Object right)
Test if left >= right.

Parameters:
left - first value
right - second value
Returns:
test result.

toBoolean

public boolean toBoolean(java.lang.Object val)
Coerce to a boolean (not a java.lang.Boolean).

Parameters:
val - Object to be coerced.
Returns:
The boolean coerced value, or false if none possible.

toInteger

public int toInteger(java.lang.Object val)
Coerce to a int.

Parameters:
val - Object to be coerced.
Returns:
The int coerced value.

toLong

public long toLong(java.lang.Object val)
Coerce to a long (not a java.lang.Long).

Parameters:
val - Object to be coerced.
Returns:
The long coerced value.

toBigInteger

public java.math.BigInteger toBigInteger(java.lang.Object val)
Get a BigInteger from the object passed. Null and empty string maps to zero.

Parameters:
val - the object to be coerced.
Returns:
a BigDecimal.
Throws:
java.lang.NullPointerException - if val is null and mode is strict.

toBigDecimal

public java.math.BigDecimal toBigDecimal(java.lang.Object val)
Get a BigDecimal from the object passed. Null and empty string maps to zero.

Parameters:
val - the object to be coerced.
Returns:
a BigDecimal.
Throws:
java.lang.NullPointerException - if val is null and mode is strict.

toDouble

public double toDouble(java.lang.Object val)
Coerce to a double.

Parameters:
val - Object to be coerced.
Returns:
The double coerced value.
Throws:
java.lang.NullPointerException - if val is null and mode is strict.

toString

public java.lang.String toString(java.lang.Object val)
Coerce to a string.

Parameters:
val - Object to be coerced.
Returns:
The String coerced value.
Throws:
java.lang.NullPointerException - if val is null and mode is strict.

narrow

public java.lang.Number narrow(java.lang.Number original)
Given a Number, return back the value using the smallest type the result will fit into. This works hand in hand with parameter 'widening' in java method calls, e.g. a call to substring(int,int) with an int and a long will fail, but a call to substring(int,int) with an int and a short will succeed.

Parameters:
original - the original number.
Returns:
a value of the smallest type the original number will fit into.


Copyright © 2001-2010 Apache Software Foundation. All Rights Reserved.