RemoteEngine.java

/*
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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 */

import javax.script.*;

import org.openjdk.engine.python.AbstractPythonScriptEngine.PyExecMode;
import org.openjdk.engine.python.PythonException;
import org.openjdk.engine.python.PythonRemoteCompiledScript;
import org.openjdk.engine.python.PythonRemoteScriptEngine;
import org.openjdk.engine.python.PythonScriptEngine;


void main() throws IOException {
    System.setProperty("org.openjdk.engine.python.sys.prepend.path", "");
    var m = new ScriptEngineManager();
    var e = (PythonScriptEngine) m.getEngineByName("python");
    e.setExecMode(PyExecMode.FILE);

    try {
        e.eval("import os");
        e.setExecMode(PyExecMode.EVAL);
        IO.println("local pid = " + e.eval("os.getpid()"));

        e.setExecMode(PyExecMode.FILE);
        e.eval("from squaring import *");
        IO.println(e.invokeFunction("square", 27));
        e.setExecMode(PyExecMode.EVAL);
        var numbers = e.eval("[23, 44, 12]");

        var re = PythonRemoteScriptEngine.create(e);
        re.setExecMode(PyExecMode.FILE);
        re.eval("import os");
        re.setExecMode(PyExecMode.EVAL);
        IO.println("remote pid = " + re.eval("os.getpid()"));
        re.setExecMode(PyExecMode.FILE);
        re.eval("from squaring import *");
        // we can call global functions on the remote engine
        IO.println(re.invokeFunction("square", 27));
        // we can call global functions on the remote engine by passing
        // arbitaray Python picklable arguments from the local engine
        IO.println("sum of " + numbers + " is " + re.invokeFunction("sum", numbers));

        // we can compile script remotely and eval it many times
        var reCompiled = (PythonRemoteCompiledScript) re.compile("""
           for i in range(10):
                print(i*i)
           """);

        IO.println(reCompiled);
        reCompiled.eval();

        // closed the compiled script
        reCompiled.close();

        IO.println(reCompiled);
        // cannot eval after close!
        reCompiled.eval();
    } catch (ScriptException se) {
        if (se instanceof PythonException pe) {
            pe.print();
        } else {
            se.printStackTrace();
        }
    } catch (NoSuchMethodException nsme) {
        nsme.printStackTrace();
    }
}