org.springframework.data.gemfire.config.DiskStoreBeanPostProcessor.java Source code

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Here is the source code for org.springframework.data.gemfire.config.DiskStoreBeanPostProcessor.java

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/*
 * Copyright 2010-2013 the original author or authors.
 *
 * 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.springframework.data.gemfire.config;

import java.io.File;
import java.lang.reflect.Field;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.data.gemfire.DiskStoreFactoryBean.DiskDir;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;

/**
 * The DiskStoreBeanPostProcessor class post processes any GemFire Disk Store DiskDir Spring beans defined
 * in the application context to ensure that the Disk Store directory location (disk-dir) actually exists
 * before creating the Disk Store.
 *
 * @author John Blum
 * @see org.springframework.beans.factory.config.BeanPostProcessor
 * @see org.springframework.data.gemfire.DiskStoreFactoryBean.DiskDir
 * @since 1.5.0
 */
@SuppressWarnings("unused")
public class DiskStoreBeanPostProcessor implements BeanPostProcessor {

    protected final Log log = LogFactory.getLog(getClass());

    @Override
    public Object postProcessBeforeInitialization(final Object bean, final String beanName) throws BeansException {
        if (log.isDebugEnabled()) {
            log.debug(String.format("Post Processing Bean (%1$s) of Type (%2$s) with Name (%3$s)...%n", bean,
                    ObjectUtils.nullSafeClassName(bean), beanName));
        }

        if (bean instanceof DiskDir) {
            createIfNotExists((DiskDir) bean);
        }

        return bean;
    }

    private void createIfNotExists(final DiskDir diskDirectory) {
        String location = readField(diskDirectory, "location");

        File diskDirectoryFile = new File(location);

        Assert.isTrue(diskDirectoryFile.isDirectory() || diskDirectoryFile.mkdirs(),
                String.format("Failed to create Disk Directory (%1$s)%n!", location));

        if (log.isInfoEnabled()) {
            log.info(String.format("The Disk Directory either exists or was created @ Location (%1$s).%n",
                    location));
        }
    }

    @SuppressWarnings("unchecked")
    private <T> T readField(final Object obj, final String fieldName) {
        try {
            Class type = obj.getClass();
            Field field;

            do {
                field = type.getDeclaredField(fieldName);
                type = type.getSuperclass(); // traverse up the object class hierarchy
            } while (field == null && !Object.class.equals(type));

            if (field == null) {
                throw new NoSuchFieldException(
                        String.format("Field (%1$s) does not exist on Object of type (%2$s)!", fieldName,
                                ObjectUtils.nullSafeClassName(obj)));
            }

            field.setAccessible(true);

            return (T) field.get(obj);
        } catch (Exception e) {
            throw new RuntimeException(String.format("Failed to read field (%1$s) on Object of type (%2$s)!",
                    fieldName, ObjectUtils.nullSafeClassName(obj)), e);
        }
    }

    @Override
    public Object postProcessAfterInitialization(final Object bean, final String beanName) throws BeansException {
        return bean;
    }

}