2013年6月27日

Serializable

摘要: 转自http://blog.csdn.net/cdl2008sky/article/details/6747396Serizlizable 作用对于一个存在于Java虚拟机中的对象来说,其内部的状态只保持在内存中。JVM停止之后,这些状态就丢失了。在很多情况下,对象的内部状态是需要被持久化下来的。提到持久化,最直接的做法是保存到文件系统或是数据库之中。比如:对象关系映射(Object-relational mapping)。对象序列化机制(object serialization)是Java语言内建的一种对象持久化方式,可以很容易的在JVM中的活动对象和字节数组(流)之间进行转换。除了可以很简 阅读全文

posted @ 2013-06-27 09:09 Step-BY-Step 阅读(550) 评论(0) 推荐(0) 编辑

Interface Serializable

摘要: public interface SerializableSerializability of a class is enabled by the class implementing the java.io.Serializable interface. Classes that do not implement this interface will not have any of their state serialized or deserialized. All subtypes of a serializable class are themselves serializable. 阅读全文

posted @ 2013-06-27 09:02 Step-BY-Step 阅读(418) 评论(0) 推荐(0) 编辑

ICMP and InetAddress.isReachable()

摘要: In Java it is only possible to work with two types of sockets: stream based ones (or TCP ones -java.net.Socketandjava.net.ServerSocket) and datagram based ones (or UDP ones -java.net.DatagramSocketandjava.net.MulticastSocket).The open bug4727550asks to support other socket types, that will allow, fo 阅读全文

posted @ 2013-06-27 06:33 Step-BY-Step 阅读(772) 评论(0) 推荐(0) 编辑

Java 程序检查远程服务器状态

摘要: 通常我们以命令的方式判断远程服务器是否正常运行有两种方式,ping或telnet一个远程端口。假设我们要检查的远程服务器都是 Linux 系统。从 JDK 1.5 以后,InetAddress类提供一个isReachable()方法,用来判断远程主机是否可以到达,这个方法的使用的时候一定要注意以下几点:如果客户端是 Windows 系统,JDK不会向服务器发送ICMP的请求,因为 Windows 没有提供可被调用的底层接口,这时 JDK 会自动向服务器的Port 7发起一个 Socket 连接,如果连接也失败,则认为服务器无法到达,返回False。 注意在客户端执行此程序无须管理员用户,但要求 阅读全文

posted @ 2013-06-27 06:19 Step-BY-Step 阅读(3007) 评论(0) 推荐(0) 编辑

JQuery UI

摘要: jQuery UI offers a combination of interaction, effects, widgets, utilities, and themes designed to work well together or on their own.This is very usefull for the front end. 阅读全文

posted @ 2013-06-27 05:18 Step-BY-Step 阅读(226) 评论(0) 推荐(0) 编辑

the structure of the project (MVC)

摘要: HTML <--- JSP <---- JS <---- Java controller <---- DAO <---- DatabaseThe JSP Model 2 architecture.Architecturally, JSP may be viewed as a high-levelabstractionofJava servlets. JSPs are translated intoservletsat runtime; each JSP's servlet is cached and re-used until the original J 阅读全文

posted @ 2013-06-27 05:16 Step-BY-Step 阅读(241) 评论(0) 推荐(0) 编辑

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