12点睛Spring4.1-Spring Aware

12.1 Aware

• 我们设计的准则是解耦,这就意味着我们不能对Spring的IoC容器有直接的依赖,但是我们还是想我们的bean能识别容器的资源;
• 使用aware能让我们在应用的任意位置获得spring容器的资源;
• 我们通过实现aware接口来识别spring容器的资源;
• Spring包含的aware有:
  • BeanNameAware
  • BeanFactoryAware
  • ApplicationContextAware
  • MessageSourceAware
  • ApplicationEventPublisherAware
  • ResourceLoaderAware
• 实现ApplicationContextAware接口,可识别所有的资源,但最好是你用到什么就使用什么;
• 这也就意味着我们就耦合到了spring框架上了,没有spring框架你的代码将无法执行;

12.2 示例

12.2.1 新建演示bean

package com.wisely.aware;

import org.springframework.beans.factory.BeanNameAware;
import org.springframework.context.ResourceLoaderAware;
import org.springframework.core.io.ResourceLoader;
import org.springframework.stereotype.Component;
@Component
public class DemoBean implements BeanNameAware,ResourceLoaderAware{
    private String name;
    private ResourceLoader loader;

    //BeanNameAware接口的方法
    public void setBeanName(String beanName) {
        this.name = beanName;

    }

    //ResourceLoaderAware接口的的方法
    public void setResourceLoader(ResourceLoader resourceLoader) {
        this.loader = resourceLoader;

    }

    public String getName() {
        return name;
    }

    public ResourceLoader getLoader() {
        return loader;
    }

}

12.2.2 新建演示用文件info.txt

jhkljhlkjhlkj
111111111111

12.2.3 测试

package com.wisely.aware;

import java.io.IOException;

import org.apache.commons.io.IOUtils;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;

public class Main {

    public static void main(String[] args) throws IOException {
        AnnotationConfigApplicationContext context =
                new AnnotationConfigApplicationContext("com.wisely.aware");
        DemoBean db = context.getBean(DemoBean.class);
        System.out.println(db.getName());
        ResourceLoader rl = db.getLoader();
        Resource r = rl.getResource("classpath:com/wisely/aware/info.txt");
        System.out.println(IOUtils.toString(r.getInputStream()));
        context.close();
    }

}

输出结果

demoBean
jhkljhlkjhlkj
111111111111