| // Copyright 2006 The Apache Software Foundation |
| // |
| // Licensed 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 org.apache.tapestry5.internal.bindings; |
| |
| import org.apache.tapestry5.Binding; |
| import org.apache.tapestry5.ioc.BaseLocatable; |
| import org.apache.tapestry5.ioc.Location; |
| import org.apache.tapestry5.ioc.internal.util.TapestryException; |
| |
| import java.lang.annotation.Annotation; |
| |
| /** |
| * Abstract base class for bindings. Assumes that the binding is read only and invariant. Subclasses must provide an |
| * implementation of {@link Binding#get()}. |
| */ |
| public abstract class AbstractBinding extends BaseLocatable implements Binding |
| { |
| public AbstractBinding() |
| { |
| this(null); |
| } |
| |
| protected AbstractBinding(Location location) |
| { |
| super(location); |
| } |
| |
| /** |
| * @throws TapestryException always |
| */ |
| public void set(Object value) |
| { |
| throw new TapestryException(BindingsMessages.bindingIsReadOnly(this), this, null); |
| } |
| |
| /** |
| * Returns true. Subclasses that do not supply a fixed, read-only value should override this method to return |
| * false. |
| */ |
| public boolean isInvariant() |
| { |
| return true; |
| } |
| |
| /** |
| * Returns the actual class, by invoking {@link Binding#get()}. Subclasses may override this method to work more |
| * efficiently (say, when the binding type is known statically). |
| */ |
| public Class getBindingType() |
| { |
| return get().getClass(); |
| } |
| |
| /** |
| * Always returns null. Bindings that provide access to a method or field will override this method to return the |
| * appropriate annotation. |
| */ |
| public <T extends Annotation> T getAnnotation(Class<T> annotationClass) |
| { |
| return null; |
| } |
| |
| } |