ClassPathResource:
String resource = ""; //相对路径
Resource resource = new ClassPathResource(resource);
//获取当前类下，同一个包中的资源
Resource resource = new ClassPathResource("文件名称",this.getClass());
FileSystemResource:
String resource = "";
//文件系统的真实路径
Resource resource = new FileSystemResource(resource);
UrlResource:
String resource = "httP://...";
resource = "file://c:/applic...";
Resource resource = new UrlResource("file://c:/applicationContext.xml");
ServletContextResource:
需要在web环境中才可以
Resource resource = new ServletContextResource(servletContext,"/WEB-INF/classes/applicationContext.xml");
我们在使用spring容器的时候，由于applicationContext是beanFactory子类，封装了更多方法功能供我们调用，所以在使用applicationContext时，会使用特定格式的字符串表示各种类型
classPath:loaded from the classpath
file:loaded as a URL,from the fileSystem
http: loaded as a URL
none /data/config.xml Depends on the underlying ApplicationContext