替换字符串中的值

Question

I have the following code and in need to replace the value on time from PT14H01M00S to 14:01:00 the following code is omit the first two char but I get 14H01M00S ,there is no way to do that without using string builder?

String time = "PT14H01M00S";
String substring = time .substring(2);
substring.replace("H", ":");
substring.replace("M", ":");
substring.replace("S", "");

System.out.println(substring);

Answer 1

You could use a regex and replace

^..(\d\d)H(\d\d)M(\d\d)S$

with

$1:$2:$3

(I leave the details of the code as an exercise for the reader.)

Answer 2

you forgot to do

String time = "PT14H01M00S";
String substring = time .substring(2);
substring = substring.replace("H", ":");
substring = substring.replace("M", ":");
substring = substring.replace("S", "");

System.out.println(substring);

so the substring is not getting the new value returned from replace method

ran it in here and got

Answer 3

It seems like you are trying to parse and format a JodaTime Period . You should not do it using the String class API. Use appropriate formatter already provided in JodaTime API.

You should build 2 PeriodFormatter s using PeriodFormatterBuilder class, one for parsing the given string into a Period , and then second for formatting the Period to the required format:

String periodString = "PT14H01M00S";

PeriodFormatter parser = new PeriodFormatterBuilder()
        .appendLiteral("PT")
        .appendHours().appendSuffix("H")
        .appendMinutes().appendSuffix("M")
        .appendSeconds().appendSuffix("S")
        .toFormatter();

PeriodFormatter formatter = new PeriodFormatterBuilder()
        .minimumPrintedDigits(2)
        .printZeroAlways()
        .appendHours()
        .appendSeparator(":")
        .appendMinutes()
        .appendSeparator(":")
        .appendSeconds()
        .toFormatter();

System.out.println(formatter.print(parser.parsePeriod(periodString)));

Output:

14:01:00

Answer 4

use this code instead :

 String time = "PT14H01M00S";
 String substring = time .substring(2);
 substring = substring.replace("H", ":");
 substring = substring.replace("M", ":");
 substring = substring.replace("S", "");

Answer 5

我认为这应该工作

String time = "PT14H01M00S".substring(2, time.length - 1).replace(/H|M/, ":");

Answer 6

the replace method doesn't change the string it was called upon, it returns a new string.

So what you want is:

String time = "PT14H01M00S";
String substring = time .substring(2);
substring = substring.replace("H", ":");
substring = substring.replace("M", ":");
substring = substring.replace("S", "");

Answer 7

I recommend the use of regular expressions to do this kind of tasks. They are very powerful to search and replace patterns of text.

Answer 8

use this code instead

 String substring = time .substring(2);
 substring = substring.replaceAll("[HM]",":").replace("S", "");