com.google.gwt.sample.dynatablemvp.server.loc.SpringServiceLocator.java Source code

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Here is the source code for com.google.gwt.sample.dynatablemvp.server.loc.SpringServiceLocator.java

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/*
 * Copyright 2011 Google Inc.
 * 
 * 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 com.google.gwt.sample.dynatablemvp.server.loc;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import javax.servlet.http.HttpServletRequest;

import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.google.web.bindery.requestfactory.server.RequestFactoryServlet;
import com.google.web.bindery.requestfactory.shared.ServiceLocator;

/**
 * This class provides an example of implementing a ServiceLocator to allow
 * RequestFactory to work with instances of service objects, instead of its default
 * behavior of mapping service calls to static methods.
 * <p>
 * There is a reference to this class in an {@literal @}Service annotation in
 * {@link com.nsn.sprint.shared.DynaTableRequestFactory}
 */
class SpringServiceLocator<E> implements ServiceLocator {

    final private Class<E> entityClass;

    @SuppressWarnings("unchecked")
    public SpringServiceLocator() {
        Type genSup = getClass().getGenericSuperclass();
        if (genSup instanceof ParameterizedType) {
            ParameterizedType genericSuperclass = (ParameterizedType) getClass().getGenericSuperclass();
            this.entityClass = (Class<E>) genericSuperclass.getActualTypeArguments()[0];
        } else
            this.entityClass = null;

    }

    public Class<E> getEntityClass() {
        return entityClass;
    }

    @Override
    public Object getInstance(Class<?> clazz) {
        final Object bean;
        if (clazz.equals(entityClass)) {
            HttpServletRequest request = RequestFactoryServlet.getThreadLocalRequest();
            ApplicationContext context = WebApplicationContextUtils
                    .getWebApplicationContext(request.getSession().getServletContext());
            bean = context.getBean(entityClass);
        } else
            bean = null;
        return bean;
    }

}