如何在Java中删除句子的第一次和最后一次出现

Question

I have a following line : |A|B|C|D|100|E|GEN|smsplus|11|11|11| and I want to remove the first and last occurrence of | .

I have to check first if the | is available at first and last

I am sure that this will bring me some down votes but really don't know how to go about.

EDIT

I also have to check for the following :

A|B|C|D|100|E|GEN|smsplus|11|11|11| and |A|B|C|D|100|E|GEN|smsplus|11|11|11 and there is no 

possibilities for || that is why I did not want to give any explanation for the same.

thanks for your valuable time.

Answer 1

You can perhaps use the regex:

^\\|(.*)\\|$

And replace by $1 :

ideone demo

If the start and end of the string are not both | , there'll be no replacement.

EDIT: As per your last comment, if you want to remove the | if it's either at the start and/or at the end of the string, then use an OR operator (there's too many | in that question I think =P):

^\\||\\|$

Replace by nothing (empty string "" )

---

EDIT2:

If the first regex is closer to what you need but also want to remove multiple pipes, add quantifiers:

^\\|+(.*)\\|+$

If the second regex (in first edit) is what you need but also want to remove multiple pipes, add quantifiers again!

^\\|+|\\|+$

Note that the replacement strings remain the same in both cases

Answer 2

Your comments lead me to believe that you want to do this:

String result = subject.replaceAll("^\\||\\|$", "");

This will change each of the following strings:

|A|B|C|
|A|B|C
A|B|C|
A|B|C

to the same string A|B|C .

See it on regex101.com .

Answer 3

Use indexOf() and lastIndexOf() from java.lang.String package

    String s="|A|B|C|D|100|E|GEN|smsplus|11|11|11|";
    s=s.substring(s.indexOf("|"),s.lastIndexOf("|"));
    System.out.println(s);    //Prints A|B|C|D|100|E|GEN|smsplus|11|11|11

Answer 4

Try,

String input = "|A|B|C|D|100|E|GEN|smsplus|11|11|11|";
input = input.substring(1, input.length()-1);

or use StringUtils.removeStart, removeEnd

StringUtils.removeStart(input, "|");
StringUtils.removeEnd(input, "|");

or

StringUtils.strip(input, "|");