言語の中の言語 - Scripting

    public static void main(String[] args) {
        // parse command line options
        String[] scriptArgs = processOptions(args);
        
        // process each script command
        for (Command cmd : scripts) {
            cmd.run(scriptArgs);
        }
        
        System.exit(EXIT_SUCCESS);
    }

        engineManager = new ScriptEngineManager();

    private static void listScriptEngines() {
        List factories = engineManager.getEngineFactories();
        for (ScriptEngineFactory factory: factories) {
            getError().println(getMessage("engine.info",
                    new Object[] { factory.getLanguageName(),
                            factory.getLanguageVersion(),
                            factory.getEngineName(),
                            factory.getEngineVersion()
            }));
        }
        System.exit(EXIT_SUCCESS);
    }

    private static ScriptEngine getScriptEngine(String lang) {
        ScriptEngine se = engines.get(lang);
        if (se == null) {
            se = engineManager.getEngineByName(lang);
            if (se == null) {
                getError().println(getMessage("engine.not.found",
                        new Object[] { lang }));
                        System.exit(EXIT_ENGINE_NOT_FOUND);
            }
            
            // initialize the engine
            initScriptEngine(se);
            // to avoid re-initialization of engine, store it in a map
            engines.put(lang, se);
        }
        return se;
    }

    private static Object evaluateString(ScriptEngine se,
            String script, boolean exitOnError) {
        try {
            return se.eval(script);
        } catch (ScriptException sexp) {
            getError().println(getMessage("string.script.error",
                    new Object[] { sexp.getMessage() }));
                    if (exitOnError)
                        System.exit(EXIT_SCRIPT_ERROR);
        } catch (Exception exp) {
            exp.printStackTrace(getError());
            if (exitOnError)
                System.exit(EXIT_SCRIPT_ERROR);
        }
        
        return null;
    }

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
 
public class ScriptSample1 {
    public ScriptSample1() {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");
        
        String script = "print('Hello, World!');";
 
        if (engine != null) {
            try {
                engine.eval(script);
            } catch (ScriptException ex) {
                ex.printStackTrace();
            }
        }
    }
 
    public static void main(String[] args) {
        new ScriptSample1();
    }
}

        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");
        
        String[] scripts = {"function printHelloWorld() {",
                            "    var text = 'Hello, World!';",
                            "    for (var i = 0; i < 10; i++) {",
                            "        print(text);",
                            "    }",
                            "}",
                            "printHelloWorld();"};
 
        if (engine != null) {
            try {
                for (String script: scripts) {
                    engine.eval(script);
                }
            } catch (ScriptException ex) {
                ex.printStackTrace();
            }
        }

        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");
        
        String[] scripts = {"function printHelloWorld() {"
                            + "    var text = 'Hello, World!';"
                            + "    for (var i = 0; i < 10; i++) {"
                            + "        print(text);"
                            + "    }"
                            + "}",
                            "printHelloWorld();"};
 
        if (engine != null) {
            try {
                for (String script: scripts) {
                    engine.eval(script);
                }
            } catch (ScriptException ex) {
                ex.printStackTrace();
            }
        }

    public ScriptSample3(String filename)
            throws FileNotFoundException, IOException {
        FileReader reader = new FileReader(filename);
 
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");
 
        if (engine != null) {
            try {
                engine.eval(reader);
            } catch (ScriptException ex) {
                ex.printStackTrace();
            }
        }
 
        reader.close();
    }

function printHelloWorld() {
    var text = 'Hello, World!';
    for (var i = 0; i < 10; i++) {
        print(text);
    }
}
  
printHelloWorld();

importPackage(java.util);
 
var date = new Date();
print(date);
print('Milliseconds: ' + date.getTime());
 
importPackage(java.lang);
 
print('Current Milliseconds: ' + System.currentTimeMillis());

var date = new java.util.Date();
print(date);
print('Milliseconds: ' + date.getTime());
  
print('Current Milliseconds: ' + java.lang.System.currentTimeMillis());

importPackage(javax.swing);
 
var frame = new JFrame("Sample");
frame.setVisible(true);

importPackage(java.awt);
 
var frame = new Packages.javax.swing.JFrame("Sample");
frame.setLayout(new FlowLayout());
 
var button = new Packages.javax.swing.JButton("OK");
frame.add(button);
 
frame.setSize(100, 100);
frame.setVisible(true);

importPackage(java.awt);
 
var frame = new Frame("Sample");
frame.setLayout(new FlowLayout());
 
var button = new Button("OK");
button.processMouseEvent = function(event) {
    java.lang.System.exit(0);
}
 
frame.add(button);
 
frame.setSize(100, 100);
frame.setVisible(true);

importPackage(java.awt);

var frame = new Packages.javax.swing.JFrame("Sample");
frame.setLayout(new FlowLayout());
 
var button = new Packages.javax.swing.JButton("OK");
 
obj = {actionPerformed: function(event) {
    print("ActionPerfomed: " + event);
}}
 
listener = new java.awt.event.ActionListener(obj);
button.addActionListener(listener);
 
frame.add(button);
 
frame.setSize(100, 100);
frame.setVisible(true);

    public ScriptSample4() {
        String script = "sample.foo('bar');";
        StringReader reader = new StringReader(script);
 
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");
 
        if (engine != null) {
            Bindings bindings = engine.getBindings(ScriptContext.ENGINE_SCOPE);
            bindings.put("sample", this);
            
            try {
                engine.eval(reader);
            } catch (ScriptException ex) {
                ex.printStackTrace();
            }
        }

        reader.close();
    }
 
    public void foo(String msg) {
        System.out.println("Foo: " + msg);
    }

    public ScriptSample5() {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");
 
        if (engine != null) {
            Class cls = engine.getClass();
            System.out.println("Engine Class: " + cls);
            System.out.println("Interfaces:");
            for (Class ifClass : cls.getInterfaces()) {
                System.out.println(ifClass);
            }
        }
    }

    public ScriptSample6() {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");
         
        String script = "function printHelloWorld() {"
                      + "    var text = 'Hello, World!';"
                      + "    for (var i = 0; i < 10; i++) {"
                      + "        print(text);"
                      + "    }"
                      + "}"
                      + "printHelloWorld();";
  
        if (engine != null) {
            try {
                Compilable compilable = (Compilable)engine;
                CompiledScript compiledScript = compilable.compile(script);
 
                compiledScript.eval();
            } catch (ScriptException ex) {
                ex.printStackTrace();
            }
        }
    }

    public ScriptSample7() {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("js");

        String script = "function printHelloWorld() {"
                      + "    var text = 'Hello, World!';"
                      + "    for (var i = 0; i < 10; i++) {"
                      + "        print(text);"
                      + "    }"
                      + "}";
        
        if (engine != null) {
            try {
                engine.eval(script);

                Invocable invocable = (Invocable)engine;
                invocable.invoke("printHelloWorld");

            } catch (NoSuchMethodException ex) {
                ex.printStackTrace();
            } catch (ScriptException ex) {
                ex.printStackTrace();
            }
        }
    }