Spring中ClassPathXmlApplicationContext类的简单使用

1、简单的用ApplicationContext作测试的话,得到Spring中定义的Bean实例(对象).能够用:

ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml"); RegisterDAO registerDAO = (RegisterDAO)ac.getBean("RegisterDAO");

若是是两个以上: ApplicationContext ac = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml","dao.xml"});

或者用通配符: ApplicationContext ac = new ClassPathXmlApplicationContext("classpath:/*.xml");

2、ClassPathXmlApplicationContext[只能读放在web-info/classes目录下的配置文件]和FileSystemXmlApplicationContext的区别

classpath:前缀是不须要的,默认就是指项目的classpath路径下面; 若是要使用绝对路径,须要加上file:前缀表示这是绝对路径;

对于FileSystemXmlApplicationContext: 默认表示的是两种:

1.没有盘符的是项目工做路径,即项目的根目录; 2.有盘符表示的是文件绝对路径.

若是要使用classpath路径,须要前缀classpath:

public class HelloClient {

protected static final Log log = LogFactory.getLog(HelloClient.class);

public static void main(String[] args) { // Resource resource = new ClassPathResource("appcontext.xml"); // BeanFactory factory = new XmlBeanFactory(resource);

// 用classpath路径
// ApplicationContext factory = new ClassPathXmlApplicationContext("classpath:appcontext.xml");
// ApplicationContext factory = new ClassPathXmlApplicationContext("appcontext.xml");

// ClassPathXmlApplicationContext使用了file前缀是能够使用绝对路径的
// ApplicationContext factory = new ClassPathXmlApplicationContext("file:F:/workspace/example/src/appcontext.xml");

// 用文件系统的路径,默认指项目的根路径
// ApplicationContext factory = new FileSystemXmlApplicationContext("src/appcontext.xml");
// ApplicationContext factory = new FileSystemXmlApplicationContext("webRoot/WEB-INF/appcontext.xml");


// 使用了classpath:前缀,这样,FileSystemXmlApplicationContext也可以读取classpath下的相对路径
// ApplicationContext factory = new FileSystemXmlApplicationContext("classpath:appcontext.xml");
// ApplicationContext factory = new FileSystemXmlApplicationContext("file:F:/workspace/example/src/appcontext.xml");

// 不加file前缀
ApplicationContext factory = new FileSystemXmlApplicationContext("F:/workspace/example/src/appcontext.xml");
IHelloWorld hw = (IHelloWorld)factory.getBean("helloworldbean");
log.info(hw.getContent("luoshifei"));

} }