package com.drighetto.jruby;
import java.io.FileReader;
import javax.script.Invocable;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
/**
* Simple class to show the execution of JRuby scripts from a Java class
*
* @author Dominique RIGHETTO <dominique.righetto@gmail.com>
*
*/
public class ScriptRunner {
/**
* Entry point
*
* @param args
* Command line
*/
@SuppressWarnings("boxing")
public static void main(String[] args) {
try {
FileReader scriptReader = null;
Object obj = null;
/* Initialize the script engine */
ScriptEngineManager m = new ScriptEngineManager();
ScriptEngine rubyEngine = m.getEngineByName("jruby");
ScriptContext scriptContext = rubyEngine.getContext();
Invocable rubyInvocableEngine = (Invocable) rubyEngine;
/*
* Sample 1 : Pass a parameter to the JRuby script that display the
* value of the parameter passed
*/
System.out.println("###SAMPLE 1");
scriptContext.setAttribute("param_from_java", "MyParamValue",
ScriptContext.ENGINE_SCOPE);
scriptReader = new FileReader(
"JRubyScripts/test_param_java_ruby.rb");
rubyEngine.eval(scriptReader, scriptContext);
scriptReader.close();
/*
* Sample 2 : Pass a parameter to the JRuby script that modify the
* parameter and return it
*/
System.out.println("###SAMPLE 2");
scriptContext.setAttribute("param_from_java", "MyParamValue",
ScriptContext.ENGINE_SCOPE);
scriptReader = new FileReader(
"JRubyScripts/test_param_java_ruby_with_return.rb");
obj = rubyEngine.eval(scriptReader, scriptContext);
scriptReader.close();
System.out
.printf(
"Parameter before script call '%s' and after script call '%s'\n",
"MyParamValue", obj);
/*
* Sample 3 : Call a JRuby script to obtain a object (thread
* subclass defined in JRuby script)
*/
System.out.println("###SAMPLE 3");
scriptContext.removeAttribute("param_from_java",
ScriptContext.ENGINE_SCOPE);
scriptReader = new FileReader(
"JRubyScripts/test_param_ruby_java_with_return.rb");
obj = rubyEngine.eval(scriptReader, scriptContext);
Thread thread = (Thread) obj;
scriptReader.close();
System.out.printf("Thread name : %s\n", thread.getName());
thread.start();
Thread.sleep(1000);// Let the thread finish...
/*
* Sample 4 : Call a specific function of a JRuby script
*/
System.out.println("###SAMPLE 4");
scriptReader = new FileReader("JRubyScripts/test_multifunctions.rb");
// Evaluate (execute) the script. Once evaluated, any functions
// in the script can be called with the invokeFunction method.
rubyEngine.eval(scriptReader);
// Call function
obj = rubyInvocableEngine.invokeFunction("function_two",
"HelloWord");
// Call method (procedure)
rubyInvocableEngine.invokeMethod("", "function_one", new Object[0]);
scriptReader.close();
System.out.printf("Return of the function '%s'\n", obj);
} catch (ScriptException se) {
System.out.println("########EXCEPTION");
System.out.printf("#Filename : %s\n", se.getFileName());
System.out.printf("#ColumnNumber : %s\n", se.getColumnNumber());
System.out.printf("#LineNumber : %s\n", se.getLineNumber());
System.out.printf("#Message : %s\n", se.getMessage());
System.out.println("#################");
} catch (Exception e) {
e.printStackTrace();
}
}
}