正则表达式matcher.group用法

 1     @Test
 2     public void test1() {
 3         Pattern pattern = Pattern.compile("页面下载失败\\.url:\\[http://[a-z0-9]+\\.(.+)/.+\\]\\.当前时间戳:\\[([0-9]+)\\]");
 4         Matcher matcher = pattern.matcher("页面下载失败.url:[http://item.jd.com/15626278.html].当前时间戳:[1471415298943]");
 5         if(matcher.find()){
 6             String top_domain = matcher.group(1);
 7             String curr_time = matcher.group(2);
 8             System.out.println(top_domain+"--"+"--"+curr_time);//jd.com----1471415298943
 9         }
10     }
11     
12     @Test
13     public void test2(){
14         String url = "https://item.jd.com/698763154.html";
15         Pattern pattern = Pattern.compile("https://item.jd.com/([0-9]+).html");
16         Matcher matcher = pattern.matcher(url);
17         if(matcher.find()){
18             System.out.println(matcher.group(1));//698763154
19             System.out.println(matcher.group(0));//https://item.jd.com/698763154.html
20         }
21     }
22     
23     @Test
24     public void test3(){
25         String str = "Hello,World! in Java.";
26         Pattern pattern = Pattern.compile("W(or)(ld!)");
27         Matcher matcher = pattern.matcher(str);
28         while(matcher.find()){
29              System.out.println("Group 0:"+matcher.group(0));//得到第0组——整个匹配
30              System.out.println("Group 1:"+matcher.group(1));//得到第一组匹配——与(or)匹配的
31              System.out.println("Group 2:"+matcher.group(2));//得到第二组匹配——与(ld!)匹配的，组也就是子表达式
32              System.out.println("Start 0:"+matcher.start(0)+" End 0:"+matcher.end(0));//总匹配的索引
33              System.out.println("Start 1:"+matcher.start(1)+" End 1:"+matcher.end(1));//第一组匹配的索引
34              System.out.println("Start 2:"+matcher.start(2)+" End 2:"+matcher.end(2));//第二组匹配的索引
35              System.out.println(str.substring(matcher.start(0),matcher.end(1)));//从总匹配开始索引到第1组匹配的结束索引之间子串——Wor
36         }        
37     }