这几天开始了XML之旅,一些体会和大家说说……
XML涉及的方面太多,学起来比较费劲。不过学XML首先得学好XPATH。
1、先要了解XML结构.
1)序言
<?xml version="1.0"?>
<!DOCTYPE 文档元素 SYSTEM "url">
2)主体
<books>
<book>
<书名>XML</书名>
<价格>100</价格>
</book>
</books>
3)尾声
尾声不是必须的
2、明确“根元素”不是“文档元素”
3、一个简单练习
1)定义DTD
<? xml version="1.0" encoding="UTF-8" ?> <!-- 元素类型声明 --> <! ELEMENT players (player*) > <! ELEMENT player (name,score_1,score_2,touch_times) > <! ELEMENT name (#PCDATA) > <! ELEMENT score_1 (#PCDATA) > <! ELEMENT score_2 (#PCDATA) > <! ELEMENT touch_times (#PCDATA) >
也可以用schema来验证有效性，以后再和大家讨论下schema
2)XML文档
<? xml version="1.0" encoding="UTF-8" ?> <? xml-stylesheet type="text/xsl" href="x_players.xsl" ?> <! DOCTYPE players SYSTEM "x_players.dtd" > < players > < player > < name > Vivian Richards </ name > < score_1 > 76 </ score_1 > < score_2 > 26 </ score_2 > < touch_times > 276 </ touch_times > </ player > < player > < name > Sachin Tendulkar </ name > < score_1 > 45 </ score_1 > < score_2 > 30 </ score_2 > < touch_times > 250 </ touch_times > </ player > < player > < name > Steve Waugh </ name > < score_1 > 49 </ score_1 > < score_2 > 22 </ score_2 > < touch_times > 208 </ touch_times > </ player > < player > < name > Sunil Gavaskar </ name > < score_1 > 86 </ score_1 > < score_2 > 32 </ score_2 > < touch_times > 200 </ touch_times > </ player > </ players >
3)用XSL转换显示内容
<? xml version="1.0" encoding="UTF-8" ?> < xsl:stylesheet version ="1.0" xmlns:xsl ="http://www.w3.org/1999/XSL/Transform" xmlns:fo ="http://www.w3.org/1999/XSL/Format" > < xsl:output method ="html" media-type ="all" /> < xsl:template match ="/" > < html > < head > < title > 选手得分情况表 </ title > < style type ="text/css" > table{font-size:12px;background-color:black;} th{text-align:center;background-color:#ccc;} td{background-color:white;width:150px;} </ style > </ head > < body > < div align ="center" > < h1 > 选手得分情况表 </ h1 > </ div > < div align ="center" > < table cellpadding ="5px" cellspacing ="1px" > < tbody > < tr > < th > 选手 </ th > < th > No.得分超过50的次数 </ th > < th > 得分超过100的次数 </ th > < th > No.有效接球次数 </ th > </ tr > < xsl:for-each select ="players/player" > < tr > < td >< xsl:value-of select ="name" /></ td > < td >< xsl:value-of select ="score_1" /></ td > < td >< xsl:value-of select ="score_2" /></ td > < td >< xsl:value-of select ="touch_times" /></ td > </ tr > </ xsl:for-each > </ tbody > </ table > </ div > </ body > </ html > </ xsl:template > </ xsl:stylesheet >
这样,就用到了DTD和XSL,要明白XSL转换,首先要了解XPATH语言.
XPATH实现了对XML文档的定位.上面的例子中match="/"匹配了文档的根节点.定义了文档的上下文.
接着用<xsl:for-each>来循环并取出相应节点的文本内容.其中select属性包含了XPATH表达式和定位路径.
