java - Remove string after second colon in Java

Question

I would like to remove the string after the second colon and add a new string behind.

I have a maker when clicking on a marker I add the string using ALertDialog on the marker title so I can get those value to the process for a text file. But if I select that marker again I want to remove that text after colon so I don't add duplicate string again.

I checked this link but it uses a regular expression and I don't have any experience with that.

My String = W:3:ER1,ER2,ER3,,,,

Output = W:3

I would like to remove the string after the second colon so I can attach my string

Here is my onMarkerClick

      @Override
    public boolean onMarkerClick(final Marker marker) {
        final String[] title = {marker.getTitle()};
        Bitmap smallDot = Bitmap.createScaledBitmap(getBitmapFromVectorDrawable(getApplicationContext(),
                R.drawable.blue_dot), 15, 15, false);

        final String[] selectedItems = {"", "", "", "", ""};

        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle("Enable Relays");

        // add a checkbox list
        final String[] relays = {"Relay 1", "Relay 2", "Relay 3", "Relay 4", "Implement"};
        boolean[] checkedItems = {true, false, false, true, false};


        builder.setMultiChoiceItems(relays, null, new DialogInterface.OnMultiChoiceClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which, boolean isChecked) {

                if (isChecked) {
                    // If the user checked the item, add it to the selected items
                    selectedItems[which] = "ER" + (which + 1);
                } else if (!isChecked) {
                    // Else, if the item is already in the array, remove it
                    selectedItems[which] = "";
                }
                Toast.makeText(MainActivity.this, "" + Arrays.toString(selectedItems), Toast.LENGTH_LONG).show();

            }
        }).setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

//                title[0] +=  ":" + selectedItems[0] + "," + selectedItems[1] + "," + selectedItems[2] + "," + selectedItems[3] + "," + selectedItems[4];

                int commas = 0;
                for (int i = 0; i < title[0].length(); i++) {
                    if (title[0].charAt(i) == ',') commas++;
                }
                if (!title[0].contains("ER1") && commas <= 4)
                    title[0] += ":" + selectedItems[0];
                if (!title[0].contains("ER2") && commas <= 4)
                    title[0] += "," + selectedItems[1];
                if (!title[0].contains("ER3") && commas <= 4)
                    title[0] += "," + selectedItems[2];
                if (!title[0].contains("ER4") && commas <= 4)
                    title[0] += "," + selectedItems[3];
                if (!title[0].contains("ER5") && commas <= 4)
                    title[0] += "," + selectedItems[4];

                marker.setTitle(title[0]);
                marker.showInfoWindow();
                Toast.makeText(MainActivity.this, "" + title[0], Toast.LENGTH_LONG).show();

            }
        }).setNegativeButton("CANCEL", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        });

        // create and show the alert dialog
        AlertDialog dialog = builder.create();
        dialog.show();

        return true;
    }

标签： javaandroid

Answer 1

First we split on the last : to get the title. Then we parse on , from the last : to get items and we filter out empty ones.

import java.util.stream.Collectors;

public class Main {
    public static void main(String[] args) {
        String raw = "W:3:ER1,ER2,ER3,,,,";
        String title = raw.substring(0, raw.lastIndexOf(":"));
        String[] selectedItems = raw.substring(raw.lastIndexOf(":")+1).split(",");
        List<String> items = Arrays.asList(selectedItems).stream().filter(str ->
            ! "".equals(str)
        ).collect(Collectors.toList());


        System.out.println("Title "+ title);
        System.out.println("Items "+ items);
    }
}

Prints

Title W:3
Items [ER1, ER2, ER3]

Edit 1 : Should handle single colon

import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class Main {
    public static void main(String[] args) {
        String raw = "W:3";
        List<String> items;
        String title;
        if (raw.replaceAll("[^:]", "").length() > 1) { // String with every :
            title = raw.substring(0, raw.lastIndexOf(":"));
            String[] selectedItems = raw.substring(raw.lastIndexOf(":") + 1).split(",");
            items = Arrays.asList(selectedItems).stream().filter(str ->
                    !"".equals(str)
            ).collect(Collectors.toList());
        } else {
            title = raw;
            items = null;
        }


        System.out.println("Title "+ title);
        System.out.println("Items "+ items);
    }
}

And prints for raw = "W:3";

Title W:3
Items null