Spring源码——Resource

Resource

定义

资源文件来自于classPath或者本地文件。

/**
 * Interface for a resource descriptor that abstracts from the actual
 * type of underlying resource, such as a file or class path resource.
 *
 * <p>An InputStream can be opened for every resource if it exists in
 * physical form, but a URL or File handle can just be returned for
 * certain resources. The actual behavior is implementation-specific.
 *

基本方法

基本方法的单元测试以及输出

/**
 * org.springframework.core.io.Resource test
 * Created by jinglongjun on 2017/3/30.
 */
public class TestResource {
    @Test
    public void testResource() throws IOException {
        Resource resource = new ClassPathResource("spring.xml");
        System.out.println(resource.exists());
        System.out.println(resource.getDescription());
        System.out.println(resource.getURL().getPath());
    }
}

输出结果：

true
class path resource [spring.xml]
/Users/jinglongjun/programe/workspace/spring/target/test-classes/spring.xml

Resouce继承关系

ClassPathResource

通过给定的ClassLoader或者ClassPath来加载资源。

/**
 * Create a new {@code ClassPathResource} for {@code ClassLoader} usage.
 * A leading slash will be removed, as the ClassLoader resource access
 * methods will not accept it.
 * @param path the absolute path within the classpath
 * @param classLoader the class loader to load the resource with,
 * or {@code null} for the thread context class loader
 * @see ClassLoader#getResourceAsStream(String)
 */
public ClassPathResource(String path, ClassLoader classLoader) {
Assert.notNull(path, "Path must not be null");
String pathToUse = StringUtils.cleanPath(path);
if (pathToUse.startsWith("/")) {
pathToUse = pathToUse.substring(1);
}
this.path = pathToUse;
this.classLoader = (classLoader != null ? classLoader : ClassUtils.getDefaultClassLoader());
}