How to convert string to operator in java

Question

I want to convert some String to an operator like this:

int value = 1;
int valueToCompare = 3;
String operation = \"<\";

if (value operation         


        

Answer 1

You can use ScriptEngine for that, works for any other JavaScript expressions also :

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;

ScriptEngineManager factory = new ScriptEngineManager();
ScriptEngine engine = factory.getEngineByName("JavaScript");


int value = 1;
int valueToCompare = 3;
String operation = "<";

if ((Boolean)engine.eval("" + value + operation + valueToCompare)) {
    System.out.println("Here we are.");  
}