I'm busy with work these days, so many interesting things that happened these days have been delayed to write. I want to describe them in the pattern of cut back（倒叙）. 

Swimming

summer is coming, we five friends went  swimming sixteen days before. After we got there, there were many people in the swimming pool. We quickly wore our swimsuits and went into the pool. The water is so cold for me that I sneezed continuously. Since I didn’t learned swim, so I can just stay in the side of the pool and do some water exercises.  Suddenly, I found that my ring is lost. Because the ring is a gift from my boyfriend, It’s means a lot for me. I was worried about the ring, but you know ,I can’t swim even ,not to mention found it below the water. My friends suiyi、 ada、wangbotian and qiqi helped me to find the ring. But all efforts were failed. We found the ring, but  lost the pendant. Many people in the pool helped me, but we still can’t find the pendant. At last , I give it up. I think maybe I can’t find it forever. Though It’s important for me, I can’t do anything anymore. It’s lost in the water. I was very sad when suiyi said he found the pendant. I clutched the hands of suiyi, can’t say any words for him. He is always stand by the side of me all the time. Every time I’m in depression, I want to talk with him, He is so friendly, so kind to me. He is my best friend. I want to say Thank you very much for him here, and I also want to say Thanks for all my friends and people in that swimming poll. They were kind to me, give me help when I was in need.  

Another English Corner

Last Friday, I , ada, suiyi , pingzi and peng went to English corner together. The day is always cloudy last week , and that day is cloudy too. But we still decided to go to the renmin university of china. After we had the supper, we went there by bike. But on the way to English corner, It rained suddenly. And It was a heavy rain. The raindrop is very big. We were drenched. We went to McDonald's. In McDonald's, we order some drink, and talk with each other, It feel very well in that atmosphere, we played some games, tell  some  jokes .It seemed that we were still in high school ,we played happily, have no anxious about our work , no worried about the money or the diet. We laughed with no misgiving. Time flies, It almost 9:30 when we found the rain was stopped. Then, we come back school by bike. It’s really a happy day for me. In the modern time, people are busy with many thinks ,such as salary, house, houseworks and so on. It seems that we are lost in the modern city, we have no time for ourselves, ever just to walking in the garden or talking with best friends . we are busy, too busy to do other things that seemed not important for our life. Maybe It’s because the life in modern time is to quickly ,people must do everything quickly so to catch up with the step of modern life . In my opinion, the means of life is just for ourselves, we can’t do other things that is at the cost of our happy . If you have some time, I suggest you getting out for some exercise or calling you best friends to talk. It will be a wonderful feeling for you! Just try!

      I heard of English Corner of RenMin University of China before, and I want to go there for some experiences all the time. But there would  have some other things occupied my time when I wanted to go there in the past two years. As I will be graduate from BUTP next year, I must finalize my job this year. From many experiences of interviews for internship , I found English is so important in interview,and My oral English is too poor to speak in any public place. I must find some methods to improve my oral English , and the best method is to speak ,speak loudly!and then the English Corner is a good place for me.

When I arrived at RenMin University of China for the first time, there were many people in there. Because it's the frist time for me, I feel shy and afraid to speak with others。I just like a little insect followed after suiyi and idodo. I feel so terrible that why I can’t speak to others. Why?Why? I must speak , just speak. Then, I departed from my friends and looked for someone to practice. At first, I even could’ t express my idea clearly , but I just speak ,speak, no matter wrong of right. Half an hour later, I feel somewhat better. And I find another person to talk with…and then another too.

Time flies. It’s almost 10:00 when I found the sky is too dark. With a satisfaction and a determination to come here next time , I go to school with my friends. On our way to school, we talk about the experiences that we just had all the time. Everyone is happy and satisfied with this activity, and all said they would come here next Friday. And For me ,it’s really a good experience.

As a conclusion, we want to tell people , everything is easy for one who do it and difficulty for one who don’t do it.

I hope I can write a short essay every week  from now on. Welcome to give me suggestion and correct my errors in my essay. Thank you!

规则总结

\s 单个空格
\S 单个非空格
\d 单个数字
\D 单个非数字
.  单个任意字符
\w 单个字符 [a-zA-Z0-9]
\W 非字符

[abd] a,b,c中的任意一个
[a-z] z到z中的任意一个
[a-zA-Z] a到z或A到Z中的任意一个（取并集）
[a-z[HQY]]a到z或H,Q,Y中的任意一个（取并集）

[a-z&&[d-f]] d到f的任意一个（取交集）
[^abc] 不包含a,b,c的单个字符（取反）
[^0-9] 非数字
[a-z&&[^m-p]] a到z中不包含m到p

下面的修饰其前面的字符出现的次数
? : 一个字符可能出现0次或1次
* ：一个字符可能出现0次或多次
+ ：一个字符可能出现1次或多次

\w+ jack wang liu a
\d+ 12345 12453 34 1
\d?\d 月份 1 10 12 01

分组（）
(abc) 只能包含abc, 且abc在一起出现一次
(abc)* abc abcabc abcabcabc 多个abc
abc* ab abcc abccc

电子邮件的表达式
\w+@\w+(\.\w+)+

{}
(abc){3} abc恰好出现3次
(abc){0,3}abc出现0－3次
(abc){1,} abc至少出现一次， 可以多次

或：
(Mr|Mrs|Miss)三个单词中的一个

随着互联网技术的发展，XML技术变得越来越重要，从而出现了很多
与XML的整合应用方面的技术，SAX就是其中之一。在这里，我就简要
谈谈java怎样使用sax对xml文档的解析。

首先，让我们来谈谈SAX对XML文档的解析机制。一般情况下，SAX 处理器
分析XML代码将生成以下事件：

Start document
Start element ()
Characters (white space)
Start element ()
Characters ()
End element ()
............
End element ()

具体解析步骤如下
一、 创建事件处理程序，SAX 提供应用程序可扩展的类 DefaultHandler。
创建的解析类config必须继承类 DefaultHandler。
如：public class Config extends DefaultHandler{}
二、使用 JAXP 来创建解析器：使用 JAXP 中的类 XMLReaderFactory
来创建解析器。首先声明 XMLReader的一个对象 parser。然后使用
XMLReaderFactory的createXMLReader方法来创建 SAXParser。
XMLReader parser =
XMLReaderFactory.createXMLReader(
"org.apache.xerces.parsers.SAXParser");
三、一旦创建了解析器，则需要将 config 设置为内容处理程序，
以便于其接收事件。
parser.setContentHandler(this);

但是，当然总会有可能在试图进行解析时，数据有问题。这时应该创建
ErrorHandler 在这样的情况下，有一个处理程序来处理错误和内容。
parser.setErrorHandler(this);
四、准备对文件进行实际解析。应用程序文件传递给 parse()，然后应用程序
会继续运行。
parser.parse(confFile);
五、接下来就开始对文档进行解析了。前面说过SAX的处理机制，SAX在处理XML流
的过程中，首先产生startDocument()事件，实际上该事件什么也没有发生，因为
还没有定义任何解析的事件。使用 startDocument() 事件只是为了通知文档的开
始。类似其它 SAX 事件，该事件抛出 SAXException。
例如：
public void startDocument()
throws SAXException {
System.out.println(
"Tallying survey results...");
}

六、跟下来，就正式开始对文件进行解析了。这时SAX会产生一个startElement()
事件，对于每个元素，都会回送一个传递给 startElement() 事件的名称。不过
解析器实际所传递是：该元素的名称空间信息；该元素的实际名称或 localName；
名称空间别名和 localName 的组合（否则是限定名或 qname）；以及该元素任何
属性。startElement() 事件还提供对元素属性的访问。将这些属性传递进称为
Attributes的数据结构。根据属性在数组中位置或属性的名称，可以检索该属性值。
例如：
public void startElement(
String namespaceURI,
String localName,
String qName,
Attributes atts)
throws SAXException {
String s = (!"".equals(localName)) ? localName : qName;

System.out.print("Start element: ");
System.out.println(localName);
tag = s;
if (localName == "Connector") {
System.out.println("name: "
+ atts.getValue("name"));
} else if (localName == "port") {
thisQuestion = atts.getValue("servername");
}else if (localName == "maxThreadPoolSize") {
thisQuestion = atts.getValue("poolname");
}
if (localName == "Database") {
System.out.println("name: "
+ atts.getValue("name"));
} else if (localName == "driverName") {
thisQuestion = atts.getValue("dataname");
}else if (localName == "encoding") {
thisQuestion = atts.getValue("codename");
}
thisElement = localName;

for (int att = 0;att < atts.getLength(); att++) {
String attName = atts.getLocalName(att);
System.out.println(" "
+ attName + ": "
+ atts.getValue(attName));
}

}
七、有了元素，接下来用 characters() 来检索实际的数据。这时可以使用下面的
方法获得实际的数据：
可以用String s = new String(ch, start, length).trim();
这个方法来获得数据。
例如：
public void characters(char[] ch,
int start,
int length)
throws SAXException {

String s = new String(ch, start, length).trim();
if (!"".equals(s)) {
if ("port".equals(tag)) {
System.out.println(Integer.parseInt(s));
} else if ("maxThreadPoolSize".equals(tag)) {
System.out.println(Integer.parseInt(s));
}
//System.out.println(tag+" = "+s);
}

s = new String(ch, start, length).trim();
if (!"".equals(s)) {
if ("driverName".equals(tag)) {
System.out.println(s);
} else if ("encoding".equals(tag)) {
System.out.println(s);
}
//System.out.println(tag+" = "+s);
}
}
八、接下来的要做的就是用endElement()来结束对一个xml的 element的解析。
例如：下面的方法
public void endElement(String namespaceURI,
String localName,
String qName)
throws SAXException {

printIndent(indent);
System.out.println("End Element: "+localName);
indent = indent - 4;
thisQuestion = "";
thisElement = "";
九、最后就是告诉程序，xml文件解析完毕，此时，用endDocument()来结束程序。
例如：
public void endDocument() {}

总的来说，sax处理xml的方法还基本上是差不多的，只是一二步的方法相对多一点,
那些其他的方法我这里就不多说了，由读者自己去查找资料。