java 正则表达式 求解 求代码 急

[Felix Yin]

<tr>
<td class="">10.5.238.184</td>
<td class="">QM_BRK_11</td>
<td class="">NBL.OUT.FILTER.REQ</td>
<td class="">0</td>
</tr>

<tr>
<td class="red">10.5.238.184</td>
<td class="red">QM_BRK_11</td>
<td class="red">NBL.OUT.MSGSERVER.REQ</td>
<td class="red">18753</td>
</tr>

我获得一个页面文件，现在我要过滤，只要class="red"的 比如：<td class="red">10.5.238.184</td>
然后在控制台输出，。求解，能提供代码，

[brightyq]

实在是用不着正则，
只需判断每一行是否以<td class="red">开头即可，如果是就输出。

[MiceRice]

最土就是这样：
String html = "<tr>\n<td class=\"\">10.5.238.184</td>\n<td class=\"\">QM_BRK_11</td>\n<td class=\"\">NBL.OUT.FILTER.REQ</td>\n<td class=\"\">0</td>\n</tr>\n\n<tr>\n<td class=\"red\">10.5.238.184</td>\n<td class=\"red\">QM_BRK_11</td>\n<td class=\"red\">NBL.OUT.MSGSERVER.REQ</td>\n<td class=\"red\">18753</td>\n</tr>";

Pattern pattern = Pattern.compile("<td class=\"red\">[^<]*</td>");

Matcher matcher = pattern.matcher(html);

while (matcher.find()) {
System.out.println(matcher.group(0));
}


局限性就是td里面不能有其它属性，如果要能智能点，那么就还需要修改。

[Felix Yin]

3QU，
请问System.out.println(matcher.group(0));
matcher.group(0)是什么意思。
[Quote=引用 2 楼 的回复:]
最土就是这样：
String html = "<tr>\n<td class=\"\">10.5.238.184</td>\n<td class=\"\">QM_BRK_11</td>\n<td class=\"\">NBL.OUT.FILTER.REQ</td>\n<td class=\"\">0</td>\n</tr>\n\n<tr>\n<td class=\"red\">10.5.238.……
[/Quote]

[MiceRice]

group(0)：取出匹配的整段
数字还可以是1～n，那么就是取出制定的匹配区，比如：

Pattern pattern = Pattern.compile("<td class=\"red\">([^<]*)</td>"); // 多加了小括号
System.out.println(matcher.group(1)); // 1，代表第一个小括号

[MiceRice]

给你个匹配能力更强的写法：

String html = "<tr>\n<td class=\"\">10.5.238.184</td>\n<td class=\"\">QM_BRK_11</td>\n<td class=\"\">NBL.OUT.FILTER.REQ</td>\n<td class=\"\">0</td>\n</tr>\n\n<tr>\n<td a=\"a\" class=\"red\" >10.5.238.184</td>\n<td class=\"red\" b=\"b\">QM_BRK_11</td>\n<td class=\"red\">NBL.OUT.MSGSERVER.REQ</td>\n<td class=\"red\">18753</td>\n</tr>";

Pattern pattern = Pattern.compile("<td\\s+([^>]+\\s+)*class=\"red\"\\s*([^>]+\\s*)*>([^<]*)</td>");

Matcher matcher = pattern.matcher(html);

while (matcher.find()) {
System.out.println(matcher.group(0));
System.out.println(matcher.group(3));
}

[Felix Yin]

谢[Quote=引用 5 楼 的回复:]
给你个匹配能力更强的写法：

String html = "<tr>\n<td class=\"\">10.5.238.184</td>\n<td class=\"\">QM_BRK_11</td>\n<td class=\"\">NBL.OUT.FILTER.REQ</td>\n<td class=\"\">0</td>\n</tr>\n\n<tr>\n<td a=\"a\" class=\……
[/Quote]