Java执行字符串中的运算公式

public static String StringfinalResult (String original) {  
            try {    
                String temp = (String)jse.eval(original);  
                return temp;  
            } catch (Exception t) {    
                return null;  
            }  
}  

public static String StringfinalResult (String original) {  
            try {    
                Object temp = jse.eval(original);  
                String result =temp.toString();  
                return result;  
            } catch (Exception t) {    
                return null;  
            }  
}