javax.script.Bindings Java Examples

@Override
public Object evaluate(final String expression, final Map<String, ?> values) throws ExpressionEvaluationException {
   LOG.debug("Evaluating JavaScript expression: {1}", expression);
   try {
      final Bindings scope = engine.createBindings();
      final StringBuilder localVars = new StringBuilder();
      for (final Entry<String, ?> entry : values.entrySet()) {

         // workaround for http://ruby.11.x6.nabble.com/undefined-local-variable-in-ScriptEngine-eval-tp3452553p3452557.html
         scope.put("$" + entry.getKey(), entry.getValue()); // register as global var
         localVars.append(entry.getKey()) // // reference as local var
            .append("=$") //
            .append(entry.getKey()) //
            .append("\n");
      }

      return engine.eval(localVars.toString() + expression, scope);
   } catch (final ScriptException ex) {
      throw new ExpressionEvaluationException("Evaluating JRuby expression failed: " + expression, ex);
   }
}
 

public static Object isNum( ScriptEngine actualContext, Bindings actualObject, Object[] ArgList,
  Object FunctionContext ) {

  if ( ArgList.length == 1 ) {
    try {
      if ( isNull( ArgList[0] ) ) {
        return null;
      } else if ( isUndefined( ArgList[0] ) ) {
        return undefinedValue;
      }
      double sArg1 = (Double) ArgList[0];
      if ( Double.isNaN( sArg1 ) ) {
        return Boolean.FALSE;
      } else {
        return Boolean.TRUE;
      }
    } catch ( Exception e ) {
      return Boolean.FALSE;
    }
  } else {
    throw new RuntimeException( "The function call isNum requires 1 argument." );
  }
}
 

public static void main(final String[] args) throws Exception {
    final ScriptEngineManager manager = new ScriptEngineManager();
    final ScriptEngine engine = manager.getEngineByName("nashorn");

    engine.put("x", "hello");
    // print global variable "x"
    engine.eval("print(x);");
    // the above line prints "hello"

    // Now, pass a different script context
    final ScriptContext newContext = new SimpleScriptContext();
    newContext.setBindings(engine.createBindings(), ScriptContext.ENGINE_SCOPE);
    final Bindings engineScope = newContext.getBindings(ScriptContext.ENGINE_SCOPE);

    // add new variable "x" to the new engineScope
    engineScope.put("x", "world");

    // execute the same script - but this time pass a different script context
    engine.eval("print(x);", newContext);
    // the above line prints "world"
}
 

@Override
public Object eval(ScriptContext context) throws ScriptException {
	// Only compile if necessary (should be only the first time!)
	if (cachedClazz == null) {
		try {
			FileWriter out;
			IOUtils.write(script, out = new FileWriter(file));
			out.flush();
			out.close();
			cachedClazz = engine.compileScript(file);
		} catch (Exception e) {
			throw new ScriptException(e);
		}
	}
	// Evaluate it
	Bindings bnd = context.getBindings(ScriptContext.ENGINE_SCOPE);
	bnd.put(ScriptEngine.FILENAME, file.getAbsolutePath());
	return engine.evalClass(cachedClazz, bnd);
}
 

public static String rpad( ScriptEngine actualContext, Bindings actualObject, Object[] ArgList,
                           Object FunctionContext ) {
  try {
    if ( ArgList.length == 3 ) {
      if ( isNull( ArgList, new int[] { 0, 1, 2 } ) ) {
        return null;
      } else if ( isUndefined( ArgList, new int[] { 0, 1, 2 } ) ) {
        return (String) undefinedValue;
      }
      String valueToPad = (String) ArgList[ 0 ];
      String filler = (String) ArgList[ 1 ];
      int size = (Integer) ArgList[ 2 ];

      while ( valueToPad.length() < size ) {
        valueToPad = valueToPad + filler;
      }
      return valueToPad;
    }
  } catch ( Exception e ) {
    throw new RuntimeException( "The function call rpad requires 3 arguments." );
  }
  return null;
}
 

@Override
public boolean nextKeyValue() throws IOException {
    while (true) {
        if (!this.lineRecordReader.nextKeyValue()) return false;
        try {
            final Bindings bindings = this.engine.createBindings();
            final StarGraph graph = StarGraph.open();
            bindings.put(GRAPH, graph);
            bindings.put(LINE, this.lineRecordReader.getCurrentValue().toString());
            final StarGraph.StarVertex sv = (StarGraph.StarVertex) script.eval(bindings);
            if (sv != null) {
                final Optional<StarGraph.StarVertex> vertex = sv.applyGraphFilter(this.graphFilter);
                if (vertex.isPresent()) {
                    this.vertexWritable.set(vertex.get());
                    return true;
                }
            }
        } catch (final ScriptException e) {
            throw new IOException(e.getMessage());
        }
    }
}
 

@Test
public void shouldProperlyHandleBindings() throws Exception {
    final Graph graph = TinkerFactory.createClassic();
    final GraphTraversalSource g = graph.traversal();
    final ScriptEngine engine = new GremlinGroovyScriptEngine();
    engine.put("g", g);
    engine.put("marko", convertToVertexId(graph, "marko"));
    Assert.assertEquals(g.V(convertToVertexId(graph, "marko")).next(), engine.eval("g.V(marko).next()"));

    final Bindings bindings = engine.createBindings();
    bindings.put("g", g);
    bindings.put("s", "marko");
    bindings.put("f", 0.5f);
    bindings.put("i", 1);
    bindings.put("b", true);
    bindings.put("l", 100l);
    bindings.put("d", 1.55555d);

    assertEquals(engine.eval("g.E().has('weight',f).next()", bindings), g.E(convertToEdgeId(graph, "marko", "knows", "vadas")).next());
    assertEquals(engine.eval("g.V().has('name',s).next()", bindings), g.V(convertToVertexId(graph, "marko")).next());
    assertEquals(engine.eval("g.V().sideEffect{it.get().property('bbb',it.get().value('name')=='marko')}.iterate();g.V().has('bbb',b).next()", bindings), g.V(convertToVertexId(graph, "marko")).next());
    assertEquals(engine.eval("g.V().sideEffect{it.get().property('iii',it.get().value('name')=='marko'?1:0)}.iterate();g.V().has('iii',i).next()", bindings), g.V(convertToVertexId(graph, "marko")).next());
    assertEquals(engine.eval("g.V().sideEffect{it.get().property('lll',it.get().value('name')=='marko'?100l:0l)}.iterate();g.V().has('lll',l).next()", bindings), g.V(convertToVertexId(graph, "marko")).next());
    assertEquals(engine.eval("g.V().sideEffect{it.get().property('ddd',it.get().value('name')=='marko'?1.55555d:0)}.iterate();g.V().has('ddd',d).next()", bindings), g.V(convertToVertexId(graph, "marko")).next());
}
 

private Object executeGremlinScript(String gremlinQuery) throws AtlasBaseException {
    GremlinGroovyScriptEngine scriptEngine = getGremlinScriptEngine();

    try {
        Bindings bindings = scriptEngine.createBindings();

        bindings.put("graph", getGraph());
        bindings.put("g", getGraph().traversal());

        Object result = scriptEngine.eval(gremlinQuery, bindings);

        return result;
    } catch (ScriptException e) {
        throw new AtlasBaseException(AtlasErrorCode.GREMLIN_SCRIPT_EXECUTION_FAILED, gremlinQuery);
    } finally {
        releaseGremlinScriptEngine(scriptEngine);
    }
}
 

public static void main(final String[] args) throws Exception {
    final ScriptEngineManager manager = new ScriptEngineManager();
    final ScriptEngine engine = manager.getEngineByName("nashorn");

    engine.put("x", "hello");
    // print global variable "x"
    engine.eval("print(x);");
    // the above line prints "hello"

    // Now, pass a different script context
    final ScriptContext newContext = new SimpleScriptContext();
    newContext.setBindings(engine.createBindings(), ScriptContext.ENGINE_SCOPE);
    final Bindings engineScope = newContext.getBindings(ScriptContext.ENGINE_SCOPE);

    // add new variable "x" to the new engineScope
    engineScope.put("x", "world");

    // execute the same script - but this time pass a different script context
    engine.eval("print(x);", newContext);
    // the above line prints "world"
}
 

@Test
public void testGetServiceProviderFromWrappedContext() throws Exception {

    final String SERVICE_PROVIDER_NAME = "service_provider_js_test";

    AuthenticationContext authenticationContext = new AuthenticationContext();
    authenticationContext.setServiceProviderName(SERVICE_PROVIDER_NAME);

    JsAuthenticationContext jsAuthenticationContext = new JsAuthenticationContext(authenticationContext);
    Bindings bindings = scriptEngine.getBindings(ScriptContext.GLOBAL_SCOPE);
    bindings.put("context", jsAuthenticationContext);

    Object result = scriptEngine.eval("context.serviceProviderName");
    assertNotNull(result);
    assertEquals(result, SERVICE_PROVIDER_NAME, "Service Provider name set in AuthenticationContext is not " +
        "accessible from JSAuthenticationContext");
}
 

public static String expandTemplate(Reader reader, Map<String, Object> values) {
    StringWriter writer = new StringWriter();
    ScriptEngine eng = getScriptEngine();
    Bindings bind = eng.getContext().getBindings(ScriptContext.ENGINE_SCOPE);
    if (values != null) {
        bind.putAll(values);
    }
    bind.put(ENCODING_PROPERTY_NAME, Charset.defaultCharset().name());
    eng.getContext().setWriter(writer);
    try {
        eng.eval(reader);
    } catch (ScriptException ex) {
        Exceptions.printStackTrace(ex);
    }

    return writer.toString();
}
 

private Bindings buildBindings(RuleContext ctx, FromDeviceMsg msg) {
  Bindings bindings = NashornJsEvaluator.getAttributeBindings(ctx.getDeviceMetaData().getDeviceAttributes());
  if (msg != null) {
    switch (msg.getMsgType()) {
    case POST_ATTRIBUTES_REQUEST:
      bindings = NashornJsEvaluator.updateBindings(bindings, (UpdateAttributesRequest) msg);
      break;
    case POST_TELEMETRY_REQUEST:
      TelemetryUploadRequest telemetryMsg = (TelemetryUploadRequest) msg;
      for (List<KvEntry> entries : telemetryMsg.getData().values()) {
        bindings = NashornJsEvaluator.toBindings(bindings, entries);
      }
    }
  }
  return bindings;
}
 

@Test
public void testUnsupportedWithBindings() throws ScriptException {
    // Unsupported Java classes end up as `null` in default bindings
    Bindings bindings = engine.createBindings();
    Object javaObject = new JavaObject();
    bindings.put("javaObject", javaObject);

    assertThat(bindings.get("javaObject"), nullValue());
    assertThat(engine.eval("javaObject", bindings), nullValue());

    assertThat(engine.eval("typeof javaObject", bindings), instanceOfWith(String.class, is("object")));
    assertThat(engine.eval("javaObject == null", bindings),
            instanceOfWith(Boolean.class, sameInstance(Boolean.TRUE)));
    assertThat(engine.eval("javaObject === void 0", bindings),
            instanceOfWith(Boolean.class, sameInstance(Boolean.FALSE)));
    assertThat(engine.eval("javaObject === null", bindings),
            instanceOfWith(Boolean.class, sameInstance(Boolean.TRUE)));
}
 

@Test
public void createBindingsTest() {
    final ScriptEngineManager m = new ScriptEngineManager();
    final ScriptEngine e = m.getEngineByName("nashorn");
    final Bindings b = e.createBindings();
    b.put("foo", 42.0);
    Object res = null;
    try {
        res = e.eval("foo == 42.0", b);
    } catch (final ScriptException | NullPointerException se) {
        se.printStackTrace();
        fail(se.getMessage());
    }

    assertEquals(res, Boolean.TRUE);
}
 

public static String resolveIP( ScriptEngine actualContext, Bindings actualObject, Object[] ArgList,
  Object FunctionContext ) {
  String sRC = "";
  if ( ArgList.length == 2 ) {
    try {
      InetAddress addr = InetAddress.getByName( (String) ArgList[0] );
      if ( ( (String) ArgList[1] ).equals( "IP" ) ) {
        sRC = addr.getHostName();
      } else {
        sRC = addr.getHostAddress();
      }
      if ( sRC.equals( ArgList[0] ) ) {
        sRC = "-";
      }
    } catch ( Exception e ) {
      sRC = "-";
    }
  } else {
    throw new RuntimeException( "The function call resolveIP requires 2 arguments." );
  }

  return sRC;
}
 

@Test
public void itCanEnableRequireInDifferentBindingsOnTheSameEngine() throws Throwable {
  NashornScriptEngine engine =
      (NashornScriptEngine) new ScriptEngineManager().getEngineByName("nashorn");
  Bindings bindings1 = new SimpleBindings();
  Bindings bindings2 = new SimpleBindings();

  Require.enable(engine, root, bindings1);

  assertNull(engine.getBindings(ScriptContext.ENGINE_SCOPE).get("require"));
  assertNotNull(bindings1.get("require"));
  assertNull(bindings2.get("require"));
  assertEquals("file1", ((Bindings) engine.eval("require('./file1')", bindings1)).get("file1"));

  try {
    engine.eval("require('./file1')", bindings2);
    fail();
  } catch (ScriptException ignored) {
  }

  Require.enable(engine, root, bindings2);
  assertNull(engine.getBindings(ScriptContext.ENGINE_SCOPE).get("require"));
  assertNotNull(bindings2.get("require"));
  assertEquals("file1", ((Bindings) engine.eval("require('./file1')", bindings2)).get("file1"));
}
 

public Bindings createBindings(VariableScope variableScope, Bindings engineBindings) {
  List<Resolver> scriptResolvers = new ArrayList<Resolver>();
  for (ResolverFactory scriptResolverFactory: resolverFactories) {
    Resolver resolver = scriptResolverFactory.createResolver(variableScope);
    if (resolver!=null) {
      scriptResolvers.add(resolver);
    }
  }
  return new ScriptBindings(scriptResolvers, variableScope, engineBindings);
}
 

@Override
@SuppressWarnings("unchecked")
public <T> List<Invoker<T>> route(List<Invoker<T>> invokers, URL url, Invocation invocation) throws RpcException {
    try {
        List<Invoker<T>> invokersCopy = new ArrayList<Invoker<T>>(invokers);
        Compilable compilable = (Compilable) engine;
        Bindings bindings = engine.createBindings();
        bindings.put("invokers", invokersCopy);
        bindings.put("invocation", invocation);
        bindings.put("context", RpcContext.getContext());
        CompiledScript function = compilable.compile(rule);
        Object obj = function.eval(bindings);
        if (obj instanceof Invoker[]) {
            invokersCopy = Arrays.asList((Invoker<T>[]) obj);
        } else if (obj instanceof Object[]) {
            invokersCopy = new ArrayList<Invoker<T>>();
            for (Object inv : (Object[]) obj) {
                invokersCopy.add((Invoker<T>) inv);
            }
        } else {
            invokersCopy = (List<Invoker<T>>) obj;
        }
        return invokersCopy;
    } catch (ScriptException e) {
        //fail then ignore rule .invokers.
        logger.error("route error , rule has been ignored. rule: " + rule + ", method:" + invocation.getMethodName() + ", url: " + RpcContext.getContext().getUrl(), e);
        return invokers;
    }
}
 

@Test
public void testClaimAssignment() throws ScriptException {

    ClaimMapping claimMapping1 = ClaimMapping.build("", "", "", false);

    ClaimMapping claimMapping2 = ClaimMapping.build("Test.Remote.Claim.Url.2", "Test.Remote.Claim.Url.2", "",
        false);

    AuthenticatedUser authenticatedUser = new AuthenticatedUser();
    authenticatedUser.getUserAttributes().put(claimMapping1, "TestClaimVal1");
    authenticatedUser.getUserAttributes().put(claimMapping2, "TestClaimVal2");
    AuthenticationContext authenticationContext = new AuthenticationContext();
    setupAuthContextWithStepData(authenticationContext, authenticatedUser);

    JsAuthenticationContext jsAuthenticationContext = new JsAuthenticationContext(authenticationContext);
    Bindings bindings = scriptEngine.getBindings(ScriptContext.GLOBAL_SCOPE);
    bindings.put("context", jsAuthenticationContext);

    Object result = scriptEngine.eval("context.steps[1].subject.remoteClaims['Test.Remote.Claim.Url.1']");
    assertNull(result);
    result = scriptEngine.eval("context.steps[1].subject.remoteClaims['Test.Remote.Claim.Url.2']");
    assertEquals(result, "TestClaimVal2");

    scriptEngine.eval("context.steps[1].subject.remoteClaims['Test.Remote.Claim.Url.2'] = 'Modified2'");
    result = scriptEngine.eval("context.steps[1].subject.remoteClaims['Test.Remote.Claim.Url.2']");
    assertEquals(result, "Modified2");

}
 

public RowTransformer getRowTransformer(String scriptName) {
    return (Row input) -> {
        if (input == null) {
            return null;
        }
        Reader content = load(ROW_SCRIPT_FOLDER, scriptName);
        try {
            Bindings bindings = ScriptingEnvironmentProvider.create(manager, this.scriptEngineBindings, input);
            return (Row) engine.eval(content, bindings);
        } catch (ScriptException ex) {
            throw new IllegalStateException("Cannot evaluate script: " + scriptName, ex);
        }
    };
}
 

public static void main(String[] args) throws ScriptException {
	final ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
	final ScriptEngine scriptEngine = scriptEngineManager.getEngineByName( "Nashorn");
	final Bindings bindings = scriptEngine.createBindings();
	bindings.put( "str", "Let's pass from Java to JavaScript" );		         
	scriptEngine.eval( " print(str)", bindings );
}
 

@Test
public void shouldEvalScriptWithGlobalAndLocalBindings() throws Exception {
    final Bindings g = new SimpleBindings();
    g.put("x", 1);
    final GremlinExecutor gremlinExecutor = GremlinExecutor.build().globalBindings(g).create();
    final Bindings b = new SimpleBindings();
    b.put("y", 1);
    assertEquals(2, gremlinExecutor.eval("y+x", b).get());
    gremlinExecutor.close();
}
 

void process(Exchange exchange) throws Exception {
    Bindings bindings = new SimpleBindings();
    bindings.put("env", System.getenv());
    bindings.put("sys", System.getProperties());
    bindings.put("body", exchange.hasOut() ? exchange.getOut().getBody() : exchange.getIn().getBody());
    bindings.put("message", exchange.hasOut() ? exchange.getOut() : exchange.getIn());
    bindings.put("exchange", exchange);
    bindings.put("lastcommand", this.lastImplementedCommand);

    String bot = commandimpl + "\n" + PRE_COMMAND + commandname + POST_COMMAND;

    this.engine.eval(bot, bindings);
}
 

@SuppressWarnings("unchecked")
public <T> List<Invoker<T>> route(List<Invoker<T>> invokers, URL url, Invocation invocation) throws RpcException {
    try {
        List<Invoker<T>> invokersCopy = new ArrayList<Invoker<T>>(invokers);
        Compilable compilable = (Compilable) engine;
        Bindings bindings = engine.createBindings();
        bindings.put("invokers", invokersCopy);
        bindings.put("invocation", invocation);
        bindings.put("context", RpcContext.getContext());
        CompiledScript function = compilable.compile(rule);
        Object obj = function.eval(bindings);
        if (obj instanceof Invoker[]) {
            invokersCopy = Arrays.asList((Invoker<T>[]) obj);
        } else if (obj instanceof Object[]) {
            invokersCopy = new ArrayList<Invoker<T>>();
            for (Object inv : (Object[]) obj) {
                invokersCopy.add((Invoker<T>)inv);
            }
        } else {
            invokersCopy = (List<Invoker<T>>) obj;
        }
        return invokersCopy;
    } catch (ScriptException e) {
        //fail then ignore rule .invokers.
        logger.error("route error , rule has been ignored. rule: " + rule + ", method:" + invocation.getMethodName() + ", url: " + RpcContext.getContext().getUrl(), e);
        return invokers;
    }
}
 

@Test
public void globalScopeAccess() throws ScriptException {
    Bindings globalScope = engine.getBindings(ScriptContext.GLOBAL_SCOPE);
    globalScope.put("globalVar", "Aldebaran");

    assertThat(engine.eval("globalVar"), instanceOfWith(String.class, is("Aldebaran")));
}
 

@Test
public void testEvalFromFile2() throws FileNotFoundException, ScriptException {
	InputStreamReader code = getStream("hello1.kt");
	StringWriter out;
	Bindings bnd = engine.createBindings();
	bnd.put("out", new PrintWriter(out = new StringWriter()));
	Object result = engine.eval(code, bnd);
	assertNotNull(result);
	assertEquals("main", result.getClass().getDeclaredMethods()[0].getName());
	assertEquals("Hello, World!", out.toString().trim());
}
 

public void execute(Diagram d, String code) {
    try {
        Bindings b = bindings;
        b.put("graph", d);
        engine.eval(code, b);
    } catch (ScriptException ex) {
        Exceptions.printStackTrace(ex);
    }
}
 

@Test
public void shouldGetGlobalBindings() throws Exception {
    final Bindings b = new SimpleBindings();
    final Object bound = new Object();
    b.put("x", bound);
    final GremlinExecutor gremlinExecutor = GremlinExecutor.build().
            addPlugins("gremlin-groovy", triggerPlugin).
            globalBindings(b).create();
    assertEquals(bound, gremlinExecutor.getScriptEngineManager().getBindings().get("x"));
    gremlinExecutor.close();
}
 

private static GuardedInvocation getMirrorConverter(final Class<?> sourceType, final Class<?> targetType) {
    // Could've also used (targetType.isAssignableFrom(ScriptObjectMirror.class) && targetType != Object.class) but
    // it's probably better to explicitly spell out the supported target types
    if (targetType == Map.class || targetType == Bindings.class || targetType == JSObject.class || targetType == ScriptObjectMirror.class) {
        if (ScriptObject.class.isAssignableFrom(sourceType)) {
            return new GuardedInvocation(CREATE_MIRROR);
        } else if (sourceType.isAssignableFrom(ScriptObject.class) || sourceType.isInterface()) {
            return new GuardedInvocation(CREATE_MIRROR, IS_SCRIPT_OBJECT);
        }
    }
    return null;
}
 

@Test
public void isolatedBindingsAndSimpleBindings() throws ScriptException {
    Bindings binding = new SimpleBindings();
    engine.eval("var value = 'Alnitak'", binding);

    assertThat(engine.eval("value", binding), instanceOfWith(String.class, is("Alnitak")));
    assertThat(engine.eval("typeof value"), instanceOfWith(String.class, is("undefined")));
    assertThat(engine.eval("typeof value", engine.createBindings()), instanceOfWith(String.class, is("undefined")));
    assertThat(engine.eval("typeof value", new SimpleBindings()), instanceOfWith(String.class, is("undefined")));
}