如何使用Java中的正则表达式用字符串中的连续数字替换某些子字符串？

Question

I have the following text:

some cool color #12eedd more cool colors #4567aa

I want that this string will be transformed to:

some cool color #{1} more cool colors #{2}

How is it possible to do it in Java (1.6)?

What I've found so far is the regex for color: #[0-9abcdef]{3,6}

Answer 1

You can use appendReplacement and appendTail from Matcher class

String data = "some cool color #12eedd more cool colors #4567aa";
StringBuffer sb = new StringBuffer();

Pattern p = Pattern.compile("#[0-9a-f]{3,6}", Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher(data);
int i = 1;
while (m.find()) {
    m.appendReplacement(sb, "#{" + i++ + "}");
}
m.appendTail(sb);//in case there is some text left after last match

String replaced = sb.toString();
System.out.println(replaced);

output:

some cool color #{1} more cool colors #{2}

Answer 2

You can try without regex as this

    String str="some cool color #12eedd more cool colors #4567aa";
    StringBuilder sb=new StringBuilder();
    String[] arr=str.split(" ");
    int count=1;
    for(String i:arr){
       if(i.charAt(0)=='#'){
           sb.append("#{"+count+"} ");
           count++;
       }
        else {
           sb.append(i+" ");
       }
    }
    System.out.println(sb.toString());

out put:

 some cool color #{1} more cool colors #{2}

Answer 3

Well may be this is not you are looking for but you have other option without using regex, this is simple with little bit complexion :)

StringBuilder q = new StringBuilder("some cool color #12eedd more cool colors #4567aa");
int i;
int j=1;
while(q.indexOf("#")>0){
    q.replace(i=q.indexOf("#"),i+7, "${"+ j++ +"}");
}
String result = q.toString().replaceAll("\\$", "#");
System.out.println(result);

Output:

some cool color #{1} more cool colors #{2}