学习 Spring (七) Resource

Spring入门篇 学习笔记

Resource: Spring 针对资源文件的统一接口

• UrlResource: URL 对应的资源，根据一个 URL 地址即可构建
• ClassPathResource: 获取类路径下的资源文件
• FileSystemResource: 获取文件系统里面的资源
• ServletContextResource: ServletContext 封装的资源，用于访问 ServletContext 环境下的资源
• InputStreamResource: 针对于输入流封装的资源
• ByteArrayResource: 针对于字节数组封装的资源

ResourceLoader: 所有的 application context 都实现了 ResourceLoader 接口

public interface ResourceLoader{
    Resource getResource(String location);
}

ResourceLoader 注入参数前缀：

前缀	例子	解释
classpath:	classpath:com/myapp/config.xml	从 classpath 加载
file:	file:/data/config.xml	从文件系统加载
http:	http://myserver/logo.png	从 URL 加载
无	/data/config.xml	依赖于 ApplicationContext

示例

新建类：

public class MoocResource implements ApplicationContextAware  {

	private ApplicationContext applicationContext;

	@Override
	public void setApplicationContext(ApplicationContext applicationContext)
			throws BeansException {
		this.applicationContext = applicationContext;
	}

	public void resource() throws IOException {
		//Resource resource = applicationContext.getResource("classpath:config.txt");
		//Resource resource = applicationContext.getResource("file:E:\\project\\java\\demo\\learningspring\\src\\main\\resources\\config.txt");
		//Resource resource = applicationContext.getResource("https://www.cnblogs.com/victorbu/p/10430698.html");
		Resource resource = applicationContext.getResource("config.txt");
		System.out.println(resource.getFilename());
		System.out.println(resource.contentLength());
	}

}

添加配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd" >

        <bean  id="moocResource" class="com.karonda.resource.MoocResource" ></bean>

 </beans>

添加测试类：

@RunWith(BlockJUnit4ClassRunner.class)
public class TestResource extends UnitTestBase {

	public TestResource() {
		super("classpath:spring-resource.xml");
	}

	@Test
	public void testResource() {
		MoocResource resource = super.getBean("moocResource");
		try {
			resource.resource();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}

源码：learning-spring