JSTL/JSP EL (Expression Language) in a non JSP (standalone) context

Question

Can anyone recommend a framework for templating/formatting messages in a standalone application along the lines of the JSP EL (Expression Language)?

I would expect t

Answer 1

I would go for the Spring Expression language:

http://docs.spring.io/spring/docs/current/spring-framework-reference/html/expressions.html

A few examples which demonstrate the power (the first two are from the documentation):

int year = (Integer) parser.parseExpression("Birthdate.Year + 1900").getValue(context);

String city = (String) parser.parseExpression("placeOfBirth.City").getValue(context);

// weekday is a String, e.g. "Mon", time is an int, e.g. 1400 or 900
{"Thu", "Fri"}.contains(weekday) and time matches '\d{4}'

Expressions can also use object properties:

public class Data {
    private String name; // getter and setter omitted
}

Data data = new Data();
data.setName("John Doe");

ExpressionParser p = new SpelExpressionParser();
Expression e = p.parseExpression("name == 'John Doe'");
Boolean r = (Boolean) e.getValue(data); // will return true

e = p.parseExpression("Hello " + name + ", how are you ?");
String text = e.getValue(data, String.class); // text will be "Hello John Doe, how are you ?"