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

public class Text {

     public static void test2() throws ScriptException {
            String str = "43*(2 + 1.4)+2*32/(3-2.1)";
            ScriptEngineManager manager = new ScriptEngineManager();
            ScriptEngine engine = manager.getEngineByName("js");
            Object result = engine.eval(str);
            System.out.println("结果类型:" + result.getClass().getName() + ",计算结果:" + result);
        }
     public static void test1() throws ScriptException {
            String str = "(a >= 0 && a <= 5)";
            ScriptEngineManager manager = new ScriptEngineManager();
            ScriptEngine engine = manager.getEngineByName("js");
            engine.put("a", 4);
            Object result = engine.eval(str);
            System.out.println("结果类型:" + result.getClass().getName() + ",计算结果:" + result);
        }
    public static void main(String[] args) throws ScriptException {
        test1();
        test2();
        double a=3;
        String str = "43*(2 + 1.4)+a*32/(3-2.1)";

        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");
       engine.put("a", a);
        Object result = engine.eval(str);
        System.out.println("结果类型:" + result.getClass().getName() + ",计算结果:" + result);
    }

}