How to split a string on last occurrence of set a characters?

Question

I have a text file which looks like this,

sku_id||01276116147620|L|
s_code||01276116|L|
s_prnt_prd||147620|L|
s_clr_fmly||White|L|
s_disp_clr||White|L|
s_size_desc||L|L|
s_status_str||Clearance|L|
s_ftr_cd||0|L|

Currently I read the whole thing to a buffered reader and create a single string. Then I use the split function to split the line on the "|L|" characters. This is all good until the line s_size_desc||L|L|. Here the split function doesn't work as expected. I want it to split it on the second occurrence of "|L|" in that line. How can I do this?

Answer 1

1. Reverse string
2. Split on first occurrence of your delimiter string
3. Reverse string

Answer 2

Remember if you sort/reverse etc. you have to count the cost of doing so.

But this is one possibility where you just replace the spurious |L| after splitting -

String st = "sku_id||01276116147620|L|s_code||01276116|L|s_prnt_prd||147620|L|s_clr_fmly||White|L|s_disp_clr||White|L|s_size_desc||L|L|s_status_str||Clearance|L|s_ftr_cd||0|L|";

        for(String ss : st.split("\\|L\\|")) {
            System.out.println(ss.replaceAll("L\\|", ""));
        }

Answer 3

Try using a greedy regular expression, ie one that will match as much text as possible. For example, in Extended Regular Expressions,

(L\\|)+

will match one or more occurrences of "L|", and will match as many as possible, including the second "L|" in your problematic line. So split your string on a regular expression like this.

Answer 4

you can use this using a positive look behind which only use that |L| if it contains a character or number before,

String str="Your entire string";
str.split("(?<=\\w)\\|L\\|");

This should work.

Answer 5

Assuming that |L| you want to split on is always at the end of line you can use

yourString.split("(?m)\\|L\\|$")

(?m) is regex multiline flag and it makes ^ and $ anchors match start and end of lines (instead of start and end of entire string).

---

In case there are no lines separator other way to try would be checking if after |L| you split on there is no L| like

yourString.split("\\|L\\|(?!L\\|)")

---

Another solution would be creating your array without |L| while reading your data from file.

Scanner scanner = new Scanner(new File(yourFile));
while(scanner.hasNextLine()){
    String line = scanner.nextLine();
    int lastIndex = line.lastIndexOf("|L|");
    String lineWithoutL = line.substring(0,lastIndex);//do what you want with it
    System.out.println(lineWithoutL);
}