使用Pattern.compile解析一条线

Question

我想解析下面一行，在Java中的myline，它一直抛出空值。

这是我的尝试获得'000000010'。

myline = "<status> <id>000000010</id> <created_at>2012/03/11</created_at> <text>@joerogan Played as Joe Savage Rogan in Undisputed3 Career mode, won Pride GP, got UFC title shot against Shields, lost 3 times, and retired</text> <retweet_count>0</retweet_count> <user> <name>Siggi Eggertsson</name> <location>Berlin, Germany</location> <description></description> <url>http://www.siggieggertsson.com</url> </user></status>" 
p = Pattern.compile("(?i)<id.*?>(.+?)</id>", Pattern.DOTALL); 
m = regex.matcher(myline); 
id =m.group(1); 

有什么建议吗？

Answer 1

您不应该首先使用正则表达式来解析XML。

但是，除此之外，你没有正确使用正则表达式。这是不够的，实例化一个matcher对象，你还需要告诉它做的事：

if (m.find()) 
{ 
    id = m.group(1); 
} 

Answer 2

本网站可能为你提供的解析使用Java XML的一些信息 - http://www.java-samples.com/showtutorial.php?tutorialid=152

Answer 3

这个作品

String myline = "<status> <id>000000010</id> <created_at>2012/03/11</created_at> <text>@joerogan Played as Joe Savage Rogan in Undisputed3 Career mode, won Pride GP, got UFC title shot against Shields, lost 3 times, and retired</text> <retweet_count>0</retweet_count> <user> <name>Siggi Eggertsson</name> <location>Berlin, Germany</location> <description></description> <url>http://www.siggieggertsson.com</url> </user></status>"; 
Pattern p = Pattern.compile(".*<id>(.+)</id>.*"); 
Matcher m = p.matcher(myline); 
if (m.matches()) { 
    String id = m.group(1); 
    System.out.println(id); 
} 

[编辑：]这也适用，并且它的更好：

String myline = "<status> <id>000000010</id> <created_at>2012/03/11</created_at> <text>@joerogan Played as Joe Savage Rogan in Undisputed3 Career mode, won Pride GP, got UFC title shot against Shields, lost 3 times, and retired</text> <retweet_count>0</retweet_count> <user> <name>Siggi Eggertsson</name> <location>Berlin, Germany</location> <description></description> <url>http://www.siggieggertsson.com</url> </user></status>"; 
Pattern p = Pattern.compile("<id>(.+)</id>"); 
Matcher m = p.matcher(myline); 
if (m.find()) { 
    String id = m.group(1); 
    System.out.println(id); 
} 

Answer 4

强烈建议使用XML解析器。有一种内置于Java的，这是针对您的问题的示例解决方案。为简单起见省略了异常处理程序

DocumentBuilderFactory factory = DocumentBuilderFactory 
     .newInstance(); 
DocumentBuilder builder = factory.newDocumentBuilder(); 
String input = "<status> <id>000000010</id> <created_at>2012/03/11</created_at> <text>@joerogan Played as Joe Savage Rogan in Undisputed3 Career mode, won Pride GP, got UFC title shot against Shields, lost 3 times, and retired</text> <retweet_count>0</retweet_count> <user> <name>Siggi Eggertsson</name> <location>Berlin, Germany</location> <description></description> <url>http://www.siggieggertsson.com</url> </user></status>"; 
Document document = builder.parse(new InputSource(new StringReader(
     input))); 
String value = document.getElementsByTagName("id").item(0) 
     .getTextContent(); 
System.out.println(value);