Java实现计算字符串表达式

一个java 的计算字符串表达式的组件

官方站点：http://www.japisoft.com/formula/

 

贴一下支持的操作符：

FormulaOperators :

Type	Operator	Example
Numerical operators	+ - * / : Basic operators % : Modulo operators (not in high precision ) ^ : Power operators (not in high precision )	(-1 + 50*2 ) / ( 2^4 )
Boolean operators	~, xor : operators &&, and : And operators ||, or : Or operators !, not : Not operators < : less operator > : great operator <= : less or equal operator >= : great or equal operator ==, equals : equal operators !=, <> : not equal operators	!(A && (B < 10))  |  NOT ( A XOR ( B equals C ) ) A != 2 || B > 2 "string1" == "string2" A or B A or ( B <> C )
String operators	== : 2 strings equals != : 2 strings not equals <> : 2 strings not equals < : The first string less lexically than the second one > : The first string great lexically than the second one <= :The first string less or equals lexically than the second one >= : The first string great or equals lexically than the second one + : Concat string	"string1" == "string2"  : false "string1" + "a" : "string1a" "abc" > "aaa" : true "zyx" < "bcd" : false
List operators	+ : Concat two lists - : Substract a list to another one in : Test if an element is inside a list	(1,2)+(3,4) = (1,2,3,4) (1,2) + 3 = (1,2,3) 3+(1,2)=(1,2,3) (1,2,3,4)-(3,4)=(1,2) (1,2,3,4)-3=(1,2,4) 2 in (1,2,3)=true 4 in (1,2,3)=false
Other operators	= : set a variable operator [] : absolute value ² : power 2 operator % : Percent operators	A = [ 2 - A ] * 2 2² 10%=0.1
Conditional operators	if then if then else	if ( A > 2 ) then "Ok" if ( A <=2 ) THEN B=3 else B=4