| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package javax.el; |
| |
| import java.util.ArrayList; |
| import java.util.Deque; |
| import java.util.HashMap; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Locale; |
| import java.util.Map; |
| |
| public abstract class ELContext { |
| |
| private Locale locale; |
| |
| private Map<Class<?>, Object> map; |
| |
| private boolean resolved; |
| |
| private ImportHandler importHandler = null; |
| |
| private List<EvaluationListener> listeners = new ArrayList<>(); |
| |
| private Deque<Map<String,Object>> lambdaArguments = new LinkedList<>(); |
| |
| public ELContext() { |
| this.resolved = false; |
| } |
| |
| public void setPropertyResolved(boolean resolved) { |
| this.resolved = resolved; |
| } |
| |
| /** |
| * Mark the given property as resolved and notfy any interested listeners. |
| * |
| * @param base The base object on which the property was found |
| * @param property The property that was resolved |
| * |
| * @since EL 3.0 |
| */ |
| public void setPropertyResolved(Object base, Object property) { |
| setPropertyResolved(true); |
| notifyPropertyResolved(base, property); |
| } |
| |
| public boolean isPropertyResolved() { |
| return this.resolved; |
| } |
| |
| // Can't use Class<?> because API needs to match specification |
| /** |
| * Add an object to this EL context under the given key. |
| * |
| * @param key The key under which to store the object |
| * @param contextObject The object to add |
| * |
| * @throws NullPointerException |
| * If the supplied key or context is <code>null</code> |
| */ |
| public void putContext(@SuppressWarnings("rawtypes") Class key, |
| Object contextObject) { |
| if (key == null || contextObject == null) { |
| throw new NullPointerException(); |
| } |
| |
| if (this.map == null) { |
| this.map = new HashMap<>(); |
| } |
| |
| this.map.put(key, contextObject); |
| } |
| |
| // Can't use Class<?> because API needs to match specification |
| /** |
| * Obtain the context object for the given key. |
| * |
| * @param key The key of the required context object |
| * |
| * @return The value of the context object associated with the given key |
| * |
| * @throws NullPointerException |
| * If the supplied key is <code>null</code> |
| */ |
| public Object getContext(@SuppressWarnings("rawtypes") Class key) { |
| if (key == null) { |
| throw new NullPointerException(); |
| } |
| if (this.map == null) { |
| return null; |
| } |
| return this.map.get(key); |
| } |
| |
| public abstract ELResolver getELResolver(); |
| |
| /** |
| * Obtain the ImportHandler for this ELContext, creating one if necessary. |
| * This method is not thread-safe. |
| * |
| * @return the ImportHandler for this ELContext. |
| * |
| * @since EL 3.0 |
| */ |
| public ImportHandler getImportHandler() { |
| if (importHandler == null) { |
| importHandler = new ImportHandler(); |
| } |
| return importHandler; |
| } |
| |
| public abstract FunctionMapper getFunctionMapper(); |
| |
| public Locale getLocale() { |
| return this.locale; |
| } |
| |
| public void setLocale(Locale locale) { |
| this.locale = locale; |
| } |
| |
| public abstract VariableMapper getVariableMapper(); |
| |
| /** |
| * Register an EvaluationListener with this ELContext. |
| * |
| * @param listener The EvaluationListener to register |
| * |
| * @since EL 3.0 |
| */ |
| public void addEvaluationListener(EvaluationListener listener) { |
| listeners.add(listener); |
| } |
| |
| /** |
| * Obtain the list of registered EvaluationListeners. |
| * |
| * @return A list of the EvaluationListener registered with this ELContext |
| * |
| * @since EL 3.0 |
| */ |
| public List<EvaluationListener> getEvaluationListeners() { |
| return listeners; |
| } |
| |
| /** |
| * Notify interested listeners that an expression will be evaluated. |
| * |
| * @param expression The expression that will be evaluated |
| * |
| * @since EL 3.0 |
| */ |
| public void notifyBeforeEvaluation(String expression) { |
| for (EvaluationListener listener : listeners) { |
| try { |
| listener.beforeEvaluation(this, expression); |
| } catch (Throwable t) { |
| Util.handleThrowable(t); |
| // Ignore - no option to log |
| } |
| } |
| } |
| |
| /** |
| * Notify interested listeners that an expression has been evaluated. |
| * |
| * @param expression The expression that was evaluated |
| * |
| * @since EL 3.0 |
| */ |
| public void notifyAfterEvaluation(String expression) { |
| for (EvaluationListener listener : listeners) { |
| try { |
| listener.afterEvaluation(this, expression); |
| } catch (Throwable t) { |
| Util.handleThrowable(t); |
| // Ignore - no option to log |
| } |
| } |
| } |
| |
| /** |
| * Notify interested listeners that a property has been resolved. |
| * |
| * @param base The object on which the property was resolved |
| * @param property The property that was resolved |
| * |
| * @since EL 3.0 |
| */ |
| public void notifyPropertyResolved(Object base, Object property) { |
| for (EvaluationListener listener : listeners) { |
| try { |
| listener.propertyResolved(this, base, property); |
| } catch (Throwable t) { |
| Util.handleThrowable(t); |
| // Ignore - no option to log |
| } |
| } |
| } |
| |
| /** |
| * Determine if the specified name is recognised as the name of a lambda |
| * argument. |
| * |
| * @param name The name of the lambda argument |
| * |
| * @return <code>true</code> if the name is recognised as the name of a |
| * lambda argument, otherwise <code>false</code> |
| * |
| * @since EL 3.0 |
| */ |
| public boolean isLambdaArgument(String name) { |
| for (Map<String,Object> arguments : lambdaArguments) { |
| if (arguments.containsKey(name)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Obtain the value of the lambda argument with the given name. |
| * |
| * @param name The name of the lambda argument |
| * |
| * @return The value of the specified argument |
| * |
| * @since EL 3.0 |
| */ |
| public Object getLambdaArgument(String name) { |
| for (Map<String,Object> arguments : lambdaArguments) { |
| Object result = arguments.get(name); |
| if (result != null) { |
| return result; |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * Called when starting to evaluate a lambda expression so that the |
| * arguments are available to the EL context during evaluation. |
| * |
| * @param arguments The arguments in scope for the current lambda |
| * expression. |
| * @since EL 3.0 |
| */ |
| public void enterLambdaScope(Map<String,Object> arguments) { |
| lambdaArguments.push(arguments); |
| } |
| |
| /** |
| * Called after evaluating a lambda expression to signal that the arguments |
| * are no longer required. |
| * |
| * @since EL 3.0 |
| */ |
| public void exitLambdaScope() { |
| lambdaArguments.pop(); |
| } |
| |
| /** |
| * Coerce the supplied object to the requested type. |
| * |
| * @param obj The object to be coerced |
| * @param type The type to which the object should be coerced |
| * |
| * @return An instance of the requested type. |
| * |
| * @throws ELException |
| * If the conversion fails |
| * |
| * @since EL 3.0 |
| */ |
| public Object convertToType(Object obj, Class<?> type) { |
| |
| boolean originalResolved = isPropertyResolved(); |
| setPropertyResolved(false); |
| try { |
| ELResolver resolver = getELResolver(); |
| if (resolver != null) { |
| Object result = resolver.convertToType(this, obj, type); |
| if (isPropertyResolved()) { |
| return result; |
| } |
| } |
| } finally { |
| setPropertyResolved(originalResolved); |
| } |
| |
| return ELManager.getExpressionFactory().coerceToType(obj, type); |
| } |
| } |