Java Code Examples for javax.script.ScriptContext#setWriter()

/**
 * Evaluate the given script.
 * If you wish to get a resulting string, call getContext().setWriter(new StringWriter()) then call toString()
 * on the returned writer.
 * @param reader script source reader
 * @param ctx script context
 * @return the script context writer (by default a PrintWriter towards System.out)
 * @throws ScriptException
 */
public Object eval(Reader reader, ScriptContext ctx)
                   throws ScriptException
{
    initVelocityEngine(ctx);
    String fileName = getFilename(ctx);
    VelocityContext vctx = getVelocityContext(ctx);
    Writer out = ctx.getWriter();
    if (out == null)
    {
        out = new StringWriter();
        ctx.setWriter(out);
    }
    try
    {
        velocityEngine.evaluate(vctx, out, fileName, reader);
        out.flush();
    }
    catch (Exception exp)
    {
        throw new ScriptException(exp);
    }
    return out;
}
 

@Override
public Object eval(ScriptContext scriptContext) throws ScriptException
{
    VelocityContext velocityContext = VelocityScriptEngine.getVelocityContext(scriptContext);
    Writer out = scriptContext.getWriter();
    if (out == null)
    {
        out = new StringWriter();
        scriptContext.setWriter(out);
    }
    try
    {
        template.merge(velocityContext, out);
        out.flush();
    }
    catch (Exception exp)
    {
        throw new ScriptException(exp);
    }
    return out;
}
 

@Override
public void run() {
	Database database = Factory.getSession(SessionType.CURRENT).getDatabase(databasePath_);

	ScriptEngineManager manager = new ScriptEngineManager();
	ScriptEngine engine = manager.getEngineByExtension(scriptExt_);

	engine.put("database", database);
	engine.put("session", database.getAncestorSession());

	ScriptContext context = engine.getContext();
	context.setWriter(new PrintWriter(System.out));
	context.setErrorWriter(new PrintWriter(System.err));

	try {
		engine.eval(script_);
	} catch (ScriptException e) {
		throw new RuntimeException(e);
	}
}
 

@Test
public void test_method_invocation() throws Exception {
    ScriptEngine engine = new BshScriptEngineFactory().getScriptEngine();
    ScriptContext ctx = new SimpleScriptContext();
    StringWriter sw = new StringWriter();
    ctx.setWriter(sw);
    engine.setContext(ctx);
    engine.eval(
            "this.interpreter.print(new Object() {"
             + "public String toString() {"
                  +"return \"hello BeanShell\";"
             + "}"
          + "});"
        );
    assertEquals("hello BeanShell", sw.toString());
    sw.close();
}
 

public void testHelloWorldTool() throws ScriptException {
    ScriptContext context = engine.getContext();
    Properties properties = new Properties();
    properties.put("resource.loader", "class");
    properties.put("class.resource.loader.description", "Template Class Loader");
    properties.put("class.resource.loader.class",
            "org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");
    CustomEvent event = new CustomEvent("MyEvent");
    context.getBindings(ScriptContext.ENGINE_SCOPE).put("event", event);
    context.setAttribute(VelocityScriptEngine.VELOCITY_PROPERTIES_KEY, properties, ScriptContext.ENGINE_SCOPE);
    context.setAttribute(VelocityScriptEngine.FILENAME, "eventtool.vm", ScriptContext.ENGINE_SCOPE);
    Writer writer = new StringWriter();
    context.setWriter(writer);
    engine.eval("$event;\n" +
            "Event Created by $event.getName()\n" +
            "Event Created on $event.getDate()\n" +
            "Event ID is $event.getID()");
    // check string start
    String check = "This is a test event template: created by MyEvent on ";
    assertEquals(writer.toString().substring(0, check.length()), check);
}
 

/**
   * Constructs an interpreter UI pane for a SciJava scripting REPL.
   *
   * @param context The SciJava application context to use
   */
  public REPLPane(final Context context) {
    context.inject(this);
    output = new OutputPane(log);
    final JScrollPane outputScroll = new JScrollPane(output);
    outputScroll.setPreferredSize(new Dimension(440, 400));

    repl = new ScriptREPL(context, output.getOutputStream());
    repl.initialize();

    final Writer writer = output.getOutputWriter();
    final ScriptContext ctx = repl.getInterpreter().getEngine().getContext();
    ctx.setErrorWriter(writer);
    ctx.setWriter(writer);

    vars = new VarsPane(context, repl);
    vars.setBorder(new EmptyBorder(0, 0, 8, 0));

    prompt = new REPLEditor(repl, vars, output);
    context.inject(prompt);
    prompt.setREPLLanguage("Python");
    final JScrollPane promptScroll = new JScrollPane(prompt);

    final JPanel bottomPane = new JPanel();
    bottomPane.setLayout(new MigLayout("ins 0", "[grow,fill][pref]", "[grow,fill,align top]"));
    bottomPane.add(promptScroll, "spany 2");

    final JSplitPane outputAndPromptPane =
            new JSplitPane(JSplitPane.VERTICAL_SPLIT, outputScroll, bottomPane);
    outputAndPromptPane.setResizeWeight(1);
//    outputAndPromptPane.setDividerSize(2);

    mainPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, vars,
            outputAndPromptPane);
    mainPane.setDividerSize(1);
    mainPane.setDividerLocation(0);
  }
 

@Test
public void givenPythonScriptEngineIsAvailable_whenScriptInvoked_thenOutputDisplayed() throws Exception {
    StringWriter output = new StringWriter();
    ScriptContext context = new SimpleScriptContext();
    context.setWriter(output);

    ScriptEngineManager manager = new ScriptEngineManager();
    ScriptEngine engine = manager.getEngineByName("python");
    engine.eval(new FileReader(resolvePythonScriptPath("hello.py")), context);
    assertEquals("Should contain script output: ", "Hello Baeldung Readers!!", output.toString()
        .trim());
}
 

private void configureEngine() {

        ScriptContext context = new SimpleScriptContext();
        context.setWriter(output);
        context.setErrorWriter(output);

        engine.setContext(context);
        engine.put("out", output);
        engine.put("err", output);

        output.println(MessageFormat.format("Script language set to {0}.", engine.getFactory().getLanguageName()));

        final URL url = findInitScript();
        if (url != null) {
            output.println(MessageFormat.format("Loading initialisation script ''{0}''...", url));
            execute0(url, new Observer() {
                @Override
                public void onSuccess(Object value) {
                }

                @Override
                public void onFailure(Throwable throwable) {
                    output.println("Failed to load initialisation script. " +
                            "BEAM-specific language extensions are disabled.");
                    throwable.printStackTrace(output);
                }
            });
            output.println("Initialisation script loaded. BEAM-specific language extensions are enabled.");
        } else {
            output.println("No initialisation script found. " +
                    "BEAM-specific language extensions are disabled.");
        }
    }
 

/**
 * Instantiates a new connection to JSR 223 scripting engine.
 *
 * @param parameters connection parameters.
 */
public ScriptConnection(ConnectionParameters parameters) {
    super(parameters);
    String lang = parameters.getStringProperty(LANGUAGE);
    ScriptEngineManager scriptEngineManager = new ScriptEngineManager(ScriptConnection.class.getClassLoader());
    if (StringUtils.isEmpty(lang)) { //JavaScript is used by default
        LOG.fine("Script language was not specified. JavaScript is default.");
        lang = "js";
    }

    ScriptEngine engine = scriptEngineManager.getEngineByName(lang);
    if (engine == null) {
        throw new ConfigurationException("Specified " + LANGUAGE + "=" + lang + " not supported. Available values are: " +
                getAvailableEngines(scriptEngineManager));
    }
    engineWrapper = new ScriptEngineWrapper(engine);
    LOG.fine("Script engine selected: " + engine.getFactory().getEngineName());
    if (engineWrapper.isCompilable()) {
        cache = new IdentityHashMap<>();
    } else {
        LOG.info("Engine " + engine.getFactory().getEngineName() + " does not support compilation. Running in interpreted mode.");
    }
    if (engineWrapper.isNashornScriptEngine()) {
        LOG.warning("Nashorn JavaScript Engine is not fully supported. \n" +
                "See https://github.com/scriptella/scriptella-etl/issues/2 for status and workarounds.");
    }
    if (!StringUtils.isEmpty(parameters.getUrl())) { //if url is specified
        url = parameters.getResolvedUrl();
        //setUp reader and writer for it
        ScriptContext ctx = engine.getContext();
        ctx.setReader(new LazyReader());
        //JS engine bug - we have to wrap with PrintWriter, because otherwise print function won't work.
        ctx.setWriter(new PrintWriter(new LazyWriter()));
    }
    encoding = parameters.getCharsetProperty(ENCODING);
    ScriptEngineFactory f = engine.getFactory();
    setDialectIdentifier(new DialectIdentifier(f.getLanguageName(), f.getLanguageVersion()));
}
 

protected void enable() {

    console = new Console();
    console.setShell(new EnhancedShell(console.getShell())); //, scriptList));
    console.run();        
 
    // See if we have any script text from last time
    Preferences prefs = Preferences.userNodeForPackage(getClass());
    final String lastText = prefs.get(PREF_LAST_SCRIPT, null);
 
    if( lastText != null ) { 
        SwingUtilities.invokeLater( new Runnable() {
            public void run() {
                console.getInputArea().setText(lastText);
            }
        });
    }            
 
    outputWindow = console.getOutputWindow();
    frame = (JFrame)console.getFrame();
    
    GroovyShell shell = console.getShell();
 
    // So now that the console has been "run" we need to set the script
    // engine's stdout to the latest stdout.  This is done through
    // jsr223's ScriptContext.  Many Bothans died to bring us this
    // information.
    ScriptContext context = engine.getContext();
    context.setWriter(new PrintWriter(System.out));
}
 

@Test
public void test_eval_writer_unicode() throws Exception {
    ScriptEngine engine = new BshScriptEngineFactory().getScriptEngine();
    ScriptContext ctx = new SimpleScriptContext();
    StringWriter sw = new StringWriter();
    ctx.setWriter(sw);
    engine.setContext(ctx);
    engine.eval("print('\\u3456');");
    assertEquals(new String("\u3456".getBytes(), "UTF-8").charAt(0),
            new String(sw.toString().getBytes(), "UTF-8").charAt(0));
}
 

protected void start(boolean console) {
  ScriptContext context = engine.getContext();
  OutputStream out = getOutputStream();
  if (out != null) {
    context.setWriter(new PrintWriter(out));
  }
  OutputStream err = getErrorStream();
  if (err != null) {
    context.setErrorWriter(new PrintWriter(err));
  }
  // load "sa.js" initialization file
  loadInitFile();
  // load "~/jsdb.js" (if found) to perform user specific
  // initialization steps, if any.
  loadUserInitFile();

  JSJavaFactory fac = getJSJavaFactory();
  JSJavaVM jvm = (fac != null)? fac.newJSJavaVM() : null;
  // call "main" function from "sa.js" -- main expects
  // 'this' object and jvm object
  call("main", new Object[] { this, jvm });

  // if asked, start read-eval-print console
  if (console) {
    processSource(null);
  }
}
 

protected void start(boolean console) {
  ScriptContext context = engine.getContext();
  OutputStream out = getOutputStream();
  if (out != null) {
    context.setWriter(new PrintWriter(out));
  }
  OutputStream err = getErrorStream();
  if (err != null) {
    context.setErrorWriter(new PrintWriter(err));
  }
  // load "sa.js" initialization file
  loadInitFile();
  // load "~/jsdb.js" (if found) to perform user specific
  // initialization steps, if any.
  loadUserInitFile();

  JSJavaFactory fac = getJSJavaFactory();
  JSJavaVM jvm = (fac != null)? fac.newJSJavaVM() : null;
  // call "main" function from "sa.js" -- main expects
  // 'this' object and jvm object
  call("main", new Object[] { this, jvm });

  // if asked, start read-eval-print console
  if (console) {
    processSource(null);
  }
}
 

protected void start(boolean console) {
  ScriptContext context = engine.getContext();
  OutputStream out = getOutputStream();
  if (out != null) {
    context.setWriter(new PrintWriter(out));
  }
  OutputStream err = getErrorStream();
  if (err != null) {
    context.setErrorWriter(new PrintWriter(err));
  }
  // load "sa.js" initialization file
  loadInitFile();
  // load "~/jsdb.js" (if found) to perform user specific
  // initialization steps, if any.
  loadUserInitFile();

  JSJavaFactory fac = getJSJavaFactory();
  JSJavaVM jvm = (fac != null)? fac.newJSJavaVM() : null;
  // call "main" function from "sa.js" -- main expects
  // 'this' object and jvm object
  call("main", new Object[] { this, jvm });

  // if asked, start read-eval-print console
  if (console) {
    processSource(null);
  }
}
 

protected void start(boolean console) {
  ScriptContext context = engine.getContext();
  OutputStream out = getOutputStream();
  if (out != null) {
    context.setWriter(new PrintWriter(out));
  }
  OutputStream err = getErrorStream();
  if (err != null) {
    context.setErrorWriter(new PrintWriter(err));
  }
  // load "sa.js" initialization file
  loadInitFile();
  // load "~/jsdb.js" (if found) to perform user specific
  // initialization steps, if any.
  loadUserInitFile();

  JSJavaFactory fac = getJSJavaFactory();
  JSJavaVM jvm = (fac != null)? fac.newJSJavaVM() : null;
  // call "main" function from "sa.js" -- main expects
  // 'this' object and jvm object
  call("main", new Object[] { this, jvm });

  // if asked, start read-eval-print console
  if (console) {
    processSource(null);
  }
}
 

protected void start(boolean console) {
  ScriptContext context = engine.getContext();
  OutputStream out = getOutputStream();
  if (out != null) {
    context.setWriter(new PrintWriter(out));
  }
  OutputStream err = getErrorStream();
  if (err != null) {
    context.setErrorWriter(new PrintWriter(err));
  }
  // load "sa.js" initialization file
  loadInitFile();
  // load "~/jsdb.js" (if found) to perform user specific
  // initialization steps, if any.
  loadUserInitFile();

  JSJavaFactory fac = getJSJavaFactory();
  JSJavaVM jvm = (fac != null)? fac.newJSJavaVM() : null;
  // call "main" function from "sa.js" -- main expects
  // 'this' object and jvm object
  call("main", new Object[] { this, jvm });

  // if asked, start read-eval-print console
  if (console) {
    processSource(null);
  }
}
 

protected void start(boolean console) {
  ScriptContext context = engine.getContext();
  OutputStream out = getOutputStream();
  if (out != null) {
    context.setWriter(new PrintWriter(out));
  }
  OutputStream err = getErrorStream();
  if (err != null) {
    context.setErrorWriter(new PrintWriter(err));
  }
  // load "sa.js" initialization file
  loadInitFile();
  // load "~/jsdb.js" (if found) to perform user specific
  // initialization steps, if any.
  loadUserInitFile();

  JSJavaFactory fac = getJSJavaFactory();
  JSJavaVM jvm = (fac != null)? fac.newJSJavaVM() : null;
  // call "main" function from "sa.js" -- main expects
  // 'this' object and jvm object
  call("main", new Object[] { this, jvm });

  // if asked, start read-eval-print console
  if (console) {
    processSource(null);
  }
}
 

protected void start(boolean console) {
  ScriptContext context = engine.getContext();
  OutputStream out = getOutputStream();
  if (out != null) {
    context.setWriter(new PrintWriter(out));
  }
  OutputStream err = getErrorStream();
  if (err != null) {
    context.setErrorWriter(new PrintWriter(err));
  }
  // load "sa.js" initialization file
  loadInitFile();
  // load "~/jsdb.js" (if found) to perform user specific
  // initialization steps, if any.
  loadUserInitFile();

  JSJavaFactory fac = getJSJavaFactory();
  JSJavaVM jvm = (fac != null)? fac.newJSJavaVM() : null;
  // call "main" function from "sa.js" -- main expects
  // 'this' object and jvm object
  call("main", new Object[] { this, jvm });

  // if asked, start read-eval-print console
  if (console) {
    processSource(null);
  }
}
 

protected Object evaluateExpression(Object expression, Map<String, Object> parameters) {
	try {
		Object result = null;
		StringWriter writer = new StringWriter();			
		
		ScriptContext context = new SimpleScriptContext();
		for (Map.Entry<String, Object> property : engineProperties.entrySet()) {
			context.setAttribute(property.getKey(), property.getValue(), ScriptContext.ENGINE_SCOPE);
		}
		Bindings bindings = context.getBindings(ScriptContext.ENGINE_SCOPE);
		bindings.putAll(parameters);
		context.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
		context.setWriter(writer);
		if (expression instanceof CompiledScript) {
			logger.debug("About to evaluate compiled expression {} with bindings {} on engine", expression, parameters, scriptEngine);
			result = ((CompiledScript) expression).eval(context);
		} else {
			logger.debug("About to evaluate expression {} with bindings {} on engine", expression, parameters, scriptEngine);
			result = scriptEngine.eval(expression.toString(), context);
		}
		if (result == null) {
			result = writer.toString();
		}
		return result;
	} catch (ScriptException e) {
		throw new RuntimeException("Error when evaluating script", e);
	}
}
 

public void applyTo ( final ScriptContext scriptContext )
{
    scriptContext.setWriter ( new PrintWriter ( new OutputStreamWriter ( this.writerStream ) ) );
    scriptContext.setErrorWriter ( this.errorPrintWriter );
}