Unable to remove String from an Array

Question

I am currently having a little problem removing a string from an array list. Code is as follows:

    String selectedCol = req.getParameter("col");
    if (selectedCol != null) {
        ArrayList < String > ar = new ArrayList < String > ();
        String removeColumn = layout.getColumn(selectedCol).getName();
        String layOut = "layout." + key + "." + layout.getName() + ".group";
        List < String > list = Arrays.asList(props.getProp(layOut, null).replace("[", "").replace("]", "").split(","));
        ar.addAll(list);
        ar.removeAll(Arrays.asList(removeColumn));
        props.putString(layOut, ar.toString().trim());
    }

so array "ar" populates the following:

[contact, created]

I thought it could be the list size which could be incorrect however it shows up with the correct size when I do ar.size()

The following variable:

removeColumn

is populated with "created".

I have tried the following:

ar.removeAll(Arrays.asList(removeColumn));

and

ar.remove(removeColumn);

which should result in:

[contact]

however using removeall or remove did not work. I am trying to achieve this without the need of looping through.

Help?

does your array really contains the exact string you're triing to remove? If the case is different then this will not work. — Nemesis
– Nemesis, Commented May 10, 2017 at 12:29
@Nemisis I think you are right. I think the in the array is causing an issue hence why its not removing the string from the array. — Sammy Sung
– Sammy Sung, Commented May 10, 2017 at 12:30

Boann · Accepted Answer · 2017-05-10 12:31:06Z

4

You've generated the list from a string by splitting it on ",", but there are spaces between items in the string, so the two strings in your list are: "contact" and " created".

If you must parse a string in this way, change the split regex to ", ", or if you need it to be more tolerant to sloppy input, "\\s*,\\s*", allowing optional spaces before or after.

answered May 10, 2017 at 12:31

Boann

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Comments

Deep · Accepted Answer · 2017-05-10 13:11:42Z

0

Your array elements may have some white spaces. Which is leading to mismatch. You can use “\s*,\s*” in split to get rid of those white spaces. Also use trim() to remove any leading or trailing spaces.

For Example:

    List < String > list = Arrays.asList(props.getProp(layOut, null).replace("[", "").replace("]", "").trim().split("\\s*,\\s*"));

answered May 10, 2017 at 13:11

Deep

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