kelly.core.injector.AbstractSpringInjector.java Source code

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Here is the source code for kelly.core.injector.AbstractSpringInjector.java

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/*
 * Copyright 2002-2012 Zhuo Ying. All rights reserved.
 * Email: yingzhor@gmail.com
 *
 * 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 kelly.core.injector;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import kelly.core.annotation.Inject;
import kelly.core.annotation.Nullable;
import kelly.core.exception.InjectException;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.util.ReflectionUtils;

/**
 * kellyspring?
 * 
 * @author ?(yingzhor@gmail.com)
 *
 */
public abstract class AbstractSpringInjector implements Injector {

    private final ApplicationContext applicationContext;

    protected abstract ApplicationContext getApplicationContext();

    public AbstractSpringInjector() {
        this.applicationContext = getApplicationContext();
    }

    @Override
    public final void inject(Object bean) {
        if (bean == null)
            return;

        Field[] fields = getFieldsIncludingSuperclass(bean);

        for (Field field : fields) {
            Inject inject = field.getAnnotation(Inject.class);
            boolean nullable = field.getAnnotation(Nullable.class) != null;
            if (inject == null) {
                continue;
            } else {

                String beanName = inject.value();
                Object com = null;
                if ("".equals(beanName)) { // 
                    com = getBeanFromApplicationContext(field.getType());
                } else {
                    com = getBeanFromApplicationContext(beanName);
                }

                if (com == null) {
                    if (nullable) {
                        continue;
                    } else {
                        throw new InjectException("Inject failed for field " + field.toString());
                    }
                }
                ReflectionUtils.makeAccessible(field);
                ReflectionUtils.setField(field, bean, com);
            }
        }
    }

    // -------------------------------------------------------------------------

    private Field[] getFieldsIncludingSuperclass(Object bean) {
        Class<?> type = bean.getClass();
        List<Field> fields = new ArrayList<Field>();
        while (type != null) {
            fields.addAll(Arrays.asList(type.getDeclaredFields()));
            type = type.getSuperclass();
        }
        return fields.toArray(new Field[fields.size()]);
    }

    private Object getBeanFromApplicationContext(Class<?> beanType) {
        try {
            return applicationContext.getBean(beanType);
        } catch (BeansException e) {
            return null;
        }
    }

    private Object getBeanFromApplicationContext(String beanName) {
        try {
            return applicationContext.getBean(beanName);
        } catch (BeansException e) {
            return null;
        }
    }
}