| /* |
| * 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; |
| |
| public abstract class ValueExpression extends Expression { |
| |
| private static final long serialVersionUID = 8577809572381654673L; |
| |
| /** |
| * @param context The EL context for this evaluation |
| * |
| * @return The result of evaluating this value expression |
| * |
| * @throws NullPointerException |
| * If the supplied context is <code>null</code> |
| * @throws PropertyNotFoundException |
| * If a property/variable resolution failed because no match |
| * was found or a match was found but was not readable |
| * @throws ELException |
| * Wraps any exception throw whilst resolving a property or |
| * variable |
| */ |
| public abstract Object getValue(ELContext context); |
| |
| /** |
| * @param context The EL context for this evaluation |
| * @param value The value to set the property to which this value |
| * expression refers |
| * |
| * @throws NullPointerException |
| * If the supplied context is <code>null</code> |
| * @throws PropertyNotFoundException |
| * If a property/variable resolution failed because no match |
| * was found |
| * @throws PropertyNotWritableException |
| * If a property/variable resolution failed because a match was |
| * found but was not writable |
| * @throws ELException |
| * Wraps any exception throw whilst resolving a property or |
| * variable |
| */ |
| public abstract void setValue(ELContext context, Object value); |
| |
| /** |
| * @param context The EL context for this evaluation |
| * |
| * @return <code>true</code> if this expression is read only otherwise |
| * <code>false</code> |
| * |
| * @throws NullPointerException |
| * If the supplied context is <code>null</code> |
| * @throws PropertyNotFoundException |
| * If a property/variable resolution failed because no match |
| * was found or a match was found but was not readable |
| * @throws ELException |
| * Wraps any exception throw whilst resolving a property or |
| * variable |
| */ |
| public abstract boolean isReadOnly(ELContext context); |
| |
| /** |
| * @param context The EL context for this evaluation |
| * |
| * @return The type of the result of this value expression |
| * |
| * @throws NullPointerException |
| * If the supplied context is <code>null</code> |
| * @throws PropertyNotFoundException |
| * If a property/variable resolution failed because no match |
| * was found or a match was found but was not readable |
| * @throws ELException |
| * Wraps any exception throw whilst resolving a property or |
| * variable |
| */ |
| public abstract Class<?> getType(ELContext context); |
| |
| public abstract Class<?> getExpectedType(); |
| |
| /** |
| * @param context The EL context for this evaluation |
| * |
| * @return This default implementation always returns <code>null</code> |
| * |
| * @since EL 2.2 |
| */ |
| public ValueReference getValueReference(ELContext context) { |
| // Expected to be over-ridden by implementation |
| context.notifyBeforeEvaluation(getExpressionString()); |
| context.notifyAfterEvaluation(getExpressionString()); |
| return null; |
| } |
| } |