Groovy in Java test

Main.java

/*
 * The MIT License
 *
 * Copyright 2017 Youka.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package de.eis.test.groovy;

import groovy.lang.Binding;
import groovy.lang.GroovyRuntimeException;
import groovy.lang.GroovyShell;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import org.codehaus.groovy.control.CompilationFailedException;

/**
 * Application entry class.
 * 
 * @author Youka
 */
public class Main {
    // Application entry point
    public static void main(String[] args){
        // Groovy script
        final String script_name = "MyScript.groovy",
                    script_text = "println(\"${test}\")\n"
                                //+ "println(new de.eis.test.groovy.Main())\n"
                                + "return 5;";
        // Groovy environment
        final ClassLoader cl = new RestrictedClassLoader(new String[]{"de.eis."});
        // Groovy<-Java bindings
        final Binding bind = new Binding();
        final ByteArrayOutputStream log = new ByteArrayOutputStream();
        final PrintStream logPrinter = new PrintStream(log);
        bind.setProperty("out", logPrinter);
        bind.setProperty("err", logPrinter);
        bind.setProperty("test", cl);
        // Groovy shell
        final GroovyShell shell = new GroovyShell(cl, bind);
        // Run code in groovy shell
        try{
            System.out.println("Result: " + shell.evaluate(script_text, script_name));
            System.out.println("Log:\n" + log.toString());
        }catch(final CompilationFailedException e){
            System.err.println(e.getMessage());
        }catch(final GroovyRuntimeException e){
            for(final StackTraceElement trace : e.getStackTrace())
                if(trace.getFileName().equals(script_name) && trace.getMethodName().equals("run")){
                    System.err.println(trace.toString() + ": " + e.getLocalizedMessage());
                    break;
                }
        }
    }
    
    public static final class RestrictedClassLoader extends ClassLoader{
        // Restrictions for classes selection
        private final String[] restrictions;
        
        public RestrictedClassLoader(final String[] restrictions) {
            // No parent classloader
            super(null);
            // Save restrictions
            this.restrictions = restrictions;
        }
        
        @Override
        protected Class<?> findClass(String name) throws ClassNotFoundException {
            // Check by restrictions
            if(restrictions != null)
                for(final String restriction : this.restrictions)
                    if(name.startsWith(restriction))
                        throw new ClassNotFoundException("Tried to access a restricted class ('" + restriction + "')!");
            // Find by system classloader
            return ClassLoader.getSystemClassLoader().loadClass(name);
        }
    }
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>de.eis.test</groupId>
    <artifactId>GroovyTest</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>
    <name>GroovyTest</name>
    <description>Execute Groovy scripts by given source.</description>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <showDeprecation>true</showDeprecation>
                    <debug>false</debug>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>3.0.0</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>single</goal>
                        </goals>
                        <phase>package</phase>
                        <id>single</id>
                    </execution>
                </executions>
                <configuration>
                    <archive>
                        <manifest>
                            <mainClass>de.eis.test.groovy.Main</mainClass>
                        </manifest>
                    </archive>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>org.codehaus.groovy</groupId>
            <artifactId>groovy-all-minimal</artifactId>
            <version>1.5.8</version>
        </dependency>
    </dependencies>
</project>