Parse from a text file

Question

Is there a way where i can parse a method, or conditional statement from a text file? Like lets say that i had the statement in Test.txt
if(X >= Y)
do something
}and X and Y are already defined in the java file, is there a way that i could parse it so that the java code invokes it, as if it were part of the java file?

Answer 1

Here's a little Groovy demo:
import groovy.lang.GroovyShell;
* To run this demo,
*  - download 'groovy-binary-1.5.5.zip': http://dist.groovy.codehaus.org/distributions/groovy-binary-1.5.5.zip
*  - unzip, and add 'lib/groovy-all-1.5.5.jar' to your classpath
public class GroovyDemo {
    public static void main(String[] args) throws Exception {
        String script =
            " if(X > Y) {  \n"+
            "   return X+X \n"+
            " } else {     \n"+
            "   return Y/4 \n"+
            " }            \n";
        System.out.println("script=\n"+script);
        GroovyShell shell = new GroovyShell();
        shell.setProperty("X", new Integer(10));
        shell.setProperty("Y", new Integer(9));
        Object value = shell.evaluate(script);
        System.out.println("value="+value+", "+value.getClass());
        shell.setProperty("X", new Integer(8));
        value = shell.evaluate(script);
        System.out.println("value="+value+", "+value.getClass());
/* output:
    script=
     if(X > Y) { 
       return X+X
     } else {    
       return Y/4
    value=20, class java.lang.Integer
    value=2.25, class java.math.BigDecimal
*/