Java with Groovy script #java #groovy

JavaWithGroovy.java

package hello.hellospring.controller;

import groovy.lang.*;
import groovy.util.GroovyScriptEngine;
import hello.hellospring.scriptRoots.ScriptRoot1;
import hello.hellospring.util.TaxCalculator;
import org.codehaus.groovy.control.CompilerConfiguration;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

import java.io.File;
import java.math.BigDecimal;
import java.net.URL;

@Controller
public class HomeController {
    static class MyClosure extends Closure {
        protected HomeController controller;

        public MyClosure(Object owner) {
            super(owner);
        }

        void setController(HomeController controller) {
            this.controller = controller;
        }

        @Override
        public Object call(Object... args) {
            return this.controller.getStringVar() + "-" + args[0] + args[1];
        }
    }


    private String stringVar = "HomeController";
    public String getStringVar() {
        return stringVar;
    }


    @GetMapping("/")
    public String home() throws Exception {
        URL url = new File("src/groovy/").toURI().toURL();
        GroovyScriptEngine engine = new GroovyScriptEngine(new URL[]{url}, this.getClass().getClassLoader());

        Class GreeterClass = engine.loadScriptByName("Test.groovy");
        GroovyObject greeter = (GroovyObject) GreeterClass.getConstructor().newInstance();

        MyClosure callback = new MyClosure(this);
        callback.setController(this);

        greeter.setProperty("a", 0.7);
        greeter.setProperty("b", 15.9);
        greeter.setProperty("callback", callback);
        TaxCalculator calculator = (TaxCalculator) greeter.getProperty("calculator");
        calculator.setHomeController(this);

        String result = (String) greeter.invokeMethod("sayHello", null);
        Double doubleResult = (Double) greeter.invokeMethod("plus", null);
        result = (String) greeter.invokeMethod("callCallback", new Object[]{"StringValue", 12.0});
        BigDecimal tax = (BigDecimal) greeter.invokeMethod("세금계산", new Object[]{5500000.0});

        CompilerConfiguration configuration = new CompilerConfiguration();
        configuration.setScriptBaseClass(ScriptRoot1.class.getName());
        GroovyShell shell = new GroovyShell(this.getClass().getClassLoader(), new Binding(), configuration);
        String strScriptCode = "a = false;\n if (a) { 세금계산(8500000.0); }\n else { 0.0; }";
        Script script = shell.parse(strScriptCode);
        tax = (BigDecimal)script.run();

        return "home";
    }
}




// src/groovy/Test.groovy
import hello.hellospring.util.*;

class Greeter {
    double a;
    double b;
    Closure callback;
    TaxCalculator calculator =  new TaxCalculator();

    String sayHello() {
        def greet = "Hello, world!"
        greet
    }

    double plus() {
        return a + b;
    }

    String callCallback(String a, double b) {
        return callback(a, b);
    }

    BigDecimal 세금계산(BigDecimal value) {
        return calculator.calc(value);
    }
}



// // src/main/hello.hellospring.scriptRoots/ScriptRoot1.java
package hello.hellospring.scriptRoots;

import groovy.lang.Script;
import hello.hellospring.util.TaxCalculator;

import java.math.BigDecimal;

public abstract class ScriptRoot1 extends Script {
    TaxCalculator calculator =  new TaxCalculator();
    BigDecimal 공제금액 = new BigDecimal(0);

    BigDecimal 세금계산(BigDecimal value) {
        return calculator.calc(value);
    }
}




// src/main/hello.hellospring.util/TaxCalculator.java
package hello.hellospring.util;

import hello.hellospring.controller.HomeController;

import java.math.BigDecimal;

public class TaxCalculator {
    private BigDecimal taxRate = new BigDecimal(0.3);
    private HomeController homeController;

    public void setTaxRate(BigDecimal rate) {
        taxRate = rate;
    }

    public void setHomeController(HomeController controller) {
        homeController = controller;
    }

    public BigDecimal calc(BigDecimal value) {
        return value.multiply(taxRate);
    }
}




// build.gradle
// https://mvnrepository.com/artifact/org.codehaus.groovy/groovy
implementation group: 'org.codehaus.groovy', name: 'groovy', version: '3.0.4'