embed_jruby_gems.java

package test.test;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;

import org.jruby.embed.LocalContextScope;
import org.jruby.embed.ScriptingContainer;

/*
 $ mkdir gems
 $ cd gems
 $ java -jar /home/itang/.rvm/rubies/jruby-1.7.18/lib/jruby.jar  -S gem install -i redis redis --no-rdoc --no-ri
 */
public class App {

	public static void main(String[] args) {
		time("main", () -> {
			App app = new App();
			app.init();

			app.test();

			return null;
		});
	}

	public void test() {
		time("require", () -> require("redis"));

		Object ret = time("script1:", () -> runScript("redis=Redis.new; redis.get 'a'"));
		println(ret);

		ret = time("script2:", () -> runScript("redis=Redis.new; redis.get 'a'"));
		println(ret);

		ret = time("script3:", () -> runScript("redis=Redis.new; redis.get 'a'"));
		System.out.println(ret);

		ret = time("script4:", () -> runScript("redis=Redis.new; redis.get 'a'"));
		System.out.println(ret);
	}

	private ScriptingContainer rubyContainer;

	private Object require(String gem) {
		return this.rubyContainer.runScriptlet("require '" + gem + "'");
	}

	private Object runScript(String script) {
		return this.rubyContainer.runScriptlet(script);
	}

	private static Object time(String title, Callable<?> run) {
		try {
			long start = System.currentTimeMillis();
			Object ret = run.call();
			long end = System.currentTimeMillis();
			System.out.println(String.format("%s: %f", title, (end - start) / 1000.0));
			return ret;
		} catch (Exception e) {
			throw new RuntimeException("error", e);
		}
	}

	private static void println(Object s) {
		System.out.println(s);
	}

	private void init() {
		List<String> paths = new ArrayList<>();
		paths.add("gems/redis/gems/redis-3.2.0/lib");
		this.rubyContainer = new ScriptingContainer(LocalContextScope.CONCURRENT);
		this.rubyContainer.setLoadPaths(paths);
	}
}