如何从java中的字符串中提取子字符串

Question

亲爱的,我有一个像这样的字符串,"... 1name:john,2name:lice,3name:mike ......".我想输出它的子串"1name:john".它在字符串中的位置不固定.我也使用substring方法,但无法得到它.你能帮我个忙吗？

谢谢.

Answer 1

String s = str.split(",")[n].trim();

如果位置是随机的,我建议制作地图:

Map<Integer, String> m = new HashMap<Integer, String>();
for (String s : str.split(",")) {
   s = s.trim();
   int keyvalstart = -1;
   for (int i = 0; i < s.length(); i++) {
      if (!Character.isDigit(i)) {
         keyvalstart = i;
         break;
      }
   }
   if (keyvalstart == -1) continue;
   String s_id    = s.substring(0, keyvalstart - 1);
   String keyvals = s.substring(keyvalstart);
   int    id      = Integer.parseInt(s_id);
   m.put(id, keyvals);
}

因此,地图将包含其各自值字符串的人员ID列表.如果您希望仅将名称存储为地图的值元素:

Map<Integer, String> m = new HashMap<Integer, String>();
for (String s : str.split(",")) {
   s = s.trim();
   int keyvalstart = -1;
   for (int i = 0; i < s.length(); i++) {
      if (!Character.isDigit(i)) {
         keyvalstart = i;
         break;
      }
   }
   if (keyvalstart == -1) continue;
   String s_id     = s.substring(0, keyvalstart - 1);
   int    id       = Integer.parseInt(s_id);
   String keyvals  = s.substring(keyvalstart);
   int    valstart = keyvals.indexOf("name: ") + "name: ".length();
   String name     = keyvals.substring(valstart);
   m.put(id, name);
}

如果要存储更多数据,在第二个示例中使用StringTokenizer更容易,如果您想存储更多数据,但我不知道您的分隔符是什么.您还需要将对象存储为地图的值以存储信息.

Answer 2

String s = "1name: john, 2name: lice, 3name: mike";
String[] names = s.split(", "); // comma and space

for(String name : names){
   System.out.println(name);
}