接口类
public interface oneinterface {
String hello(String word);
}

接口实现类
public class interfaceimp implements oneinterface {
@Override
public String hello(String word){
return("hello "+word);
}
}

不用bean需要创建实例：
public static void main(String[] args) {
oneinterface oif = new interfaceimp();
System.out.println(oif.hello("yjc"));

}

使用bean管理实例：

xml文件添加bean配置：
<bean id="nihao" class="interfaceimp"> </bean>

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("spring-ioc.xml");
interfaceimp in = (interfaceimp)context.getBean("nihao");
System.out.println(in.hello("yjc"));
}