CODEWITHSUNDEEP
javastringreplace
Yubaraj
Yubaraj

Reputation: 3988

Replace character in multiple index

I have a String like:

AB524D000000000000231200000001D0000000000000000524

The length of string is 50. Above string is one. this type of string may have lenght 250 ie. five string example:

AB524D000000000000231200000001D0000000000000000524AB524D000000000000231200000001D0000000000000000524AB524D000000000000231200000001D0000000000000000524AB524D000000000000231200000001D0000000000000000524AB524D000000000000231200000001D0000000000000000524.

Now my requirement is I need to change D to C.

I used following code to replace for one string:

String code = key.substring(0, 2);
String currency = key.substring(2, 5);
String type = key.substring(5, 6);
String amount = key.substring(6, 22);
String rate = key.substring(22, 30);
String type2 = key.substring(30, 31);
String rAmount = key.substring(31, 47);
String currency2 = key.substring(47, 50);


String finalReq = code + currency + "C" + amount + rate + "C" + rAmount + currency2;

I got following output:

AB524C000000000000231200000001C0000000000000000524

this is good for one string I mean 50 length string. But string length may 0-250 (string one to 5) but pattern is same like : AB524D000000000000231200000001D0000000000000000524.

Which is the best logic to fulfill my requirement ?.

Note: I can not do string.replaceAll('D','C') because my zeroth and first index has character I mean it may have also D.

Upvotes: 0

Views: 1120

Answers (3)

Pshemo
Pshemo

Reputation: 124215

I would say that 

replaceAll("\\G(.{5})D(.{24})D(.{19})", "$1C$2C$3")

should do the trick but I don't know if your string will only contain data in format you described or if you want to replace only D or any character that can be in places that D is.

replaceAll uses regex as first parameter, and String that can use results of that regex as second parameter. In regex

  • . dot represents any character except new line
  • .{x} represents series of any characters that is length x like .{3} can match AbZ or 1X9,
  • regex inside parenthesis (...) will create group, and each group has its unique number. This number can be used later for example in replacement String via $x where x is number of group
  • so (.{5})D(.{24})D(.{19}) will match any 5 characters (and store them in group 1), then D then 24 characters (and create store them in group 2) then D and lastly any 19 characters (and store them in group 3)
  • in replacement "$1C$2C$3" I will use strings that ware matched in first group, then instead of D will put C then will include match from group 2, then again instead of D will put C and after that include last part of match (last 19 characters after second D stored in group 3)
  • Also assure match could be done only every 50 characters from start of the string I will add \\G represents start of the string or previously match (so there can't be any characters between previous match and current match).

Upvotes: 1

CodeIsLife
CodeIsLife

Reputation: 1245

if you are sure that every string is 50 char so :

     index = finalReq.length() % 50;
      for(int i = 0; i<index; i++){
        String code = key.substring(0 + 50 * i, 2 + 50 * i);
        String currency = key.substring(2 + 50 * i , 5 + 50 * i);
        ...

        replace ...

}

Upvotes: 0

Raunak Agarwal
Raunak Agarwal

Reputation: 7228

Just use java's String replace method.

String old = "AB524D000000000000231200000001D0000000000000000524AB524D000000000000231200000001D0000000000000000524AB524D000000000000231200000001D0000000000000000524AB524D000000000000231200000001D0000000000000000524AB524D000000000000231200000001D0000000000000000524";
String output = old.replace('D', 'C');

Upvotes: 0

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