You could use Rhino which is an open source implementation of javascript entirely written in java. All you'd need to do is pass in your expression string. You'll need to set up a context and scope for javascript but that is all documented on the website:
http://www.mozilla.org/rhino I'm currently using javascript as an expression language for the JSPTL project. Here is a snippet of my code as an example of how it's setup: ----- // Creates and enters a Context. Context stores information // about the execution environment of a script Context cx = Context.enter(); // Initialize standard objects Scriptable scope = cx.initStandardObjects(null); Object eval = null; try { eval = null; eval = cx.evaluateString(scope, expression, "", 0, null); // expression // Convert to string (if needed) // result = cx.toString(eval); // Unwrap scoped object if (eval instanceof Wrapper) eval = ((Wrapper) eval).unwrap(); } catch (JavaScriptException jse) { throw new JspException(jse.getMessage()); } System.out.println("JAVASCRIPT result: " + eval + ":"); ----- Justy ----- Original Message ----- From: "Huynh Tin" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, October 04, 2001 2:11 AM Subject: How could i calulate the string expression ? > Hi all ! > I'm sorry for my basic question. > Could anybody show me how i can calculate the expression. For example > if i write directly in sources codes as follow ...it's ok. i can get the > value of expression. > double md = (1+2)*3; > > But i have a string variable that contain "(1+2)*3"...for example. i do like > this > String msExp = "(1+2)*3"; > This is my problem . How could i calculte the value of the expression. > > Are there any function to do this or any example about this. > > Thank you for your helps > > Tin Huynh > > =========================================================================== > To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". > For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST". > Some relevant FAQs on JSP/Servlets can be found at: > > http://java.sun.com/products/jsp/faq.html > http://www.esperanto.org.nz/jsp/jspfaq.html > http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP > http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets > =========================================================================== To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST". Some relevant FAQs on JSP/Servlets can be found at: http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.html http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
