internalcreator.java

反向的AJAX。最大的特性是我们成为反向的Ajax。DWR1.x允许你用javascript异步的访问java代码。DWR2.0在这上允许你建立异步java访问javascript代码。 反向的Aj

/*
 * Copyright 2007 Tim Peierls
 *
 * 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.directwebremoting.guice;

import com.google.inject.Key;
import com.google.inject.Injector;

import java.util.Map;

import org.directwebremoting.extend.Creator;

/**
 * Specialized creator implementation that uses an injector to
 * look up its instances. This class is used by {@link InternalCreatorManager}.
 * @author Tim Peierls [tim at peierls dot net]
 */
class InternalCreator implements Creator
{
    InternalCreator(Injector injector, Key key, String scriptName)
    {
        this.injector = injector;
        this.key = key;
        this.scriptName = scriptName;
    }

    public void setProperties(Map params) throws IllegalArgumentException
    {
        // Do nothing, we ignore properties (since we inject everything we create).
    }

    public Class getType()
    {
        return (Class) key.getTypeLiteral().getType();
    }
    
    public Object getInstance() throws InstantiationException
    {
        return injector.getInstance(key);
    }

    public String getScope()
    {
        return Creator.PAGE; // i.e., tell DWR always to create
    }

    public boolean isCacheable()
    {
        return true;
    }

    public String getJavascript()
    {
        return scriptName;
    }
    
    private final Injector injector;
    private final Key key;
    private final String scriptName;
}