java replace-在用空格和换行符分隔的两个标签之间替换字符串中的文本

Question

String abc = 
"<Message>
    <Details> hello </Details>
</Message>
<Customer>
   <Details> John </Details>
</Customer>
<Bank>
  <Details> BANK1 <Details>
<Bank>"

Now I want replace string whatever there between "customer/Details"(here-John) with static text(ex: Peter), that is replace John with Peter. How to do this in java probably with ReplaceAll function + regular Expression. I dont want to disturb format of string which is in xml format after replacement. Expected output

String abc = 
"<Message>
    <Details> hello </Details>
</Message>
<Customer>
   <Details> Peter</Details>
</Customer>
<Bank>
  <Details> BANK1 <Details>
<Bank>"

Answer 1

You forgot the whitespace inside the tokens you are recognising:

abc.replaceAll("(<Customer>\\s*<Details>)[^<]+(</Details>\\s*</Customer>)", "$1 Fred $2");

The \\s character class recognises all whitespace including \\n .