Regular expression pattern for matching and splitting a string in java

Question

I have this input string

Click ##$#here||action1#$## to do action A
and Click ##$#here||action2#$## to do action B 
and Click ##$#here||action3#$## to do action C

And I need the output strnig as

Click here to do action A
and Click here to do action B
and Click here to do action C

##$#here||action1#$## is an opcode pattern with "here" is replacement_string that replaces the whole opcode pattern and the "action 1" is the underlying action that has to be performed when user clicks on the "here" string (Hyper Link)

TRIED

String msg =Click ##$#here||action1#$## to do action A
and Click ##$#here||action2#$## to do action B 
and Click ##$#here||action3#$## to do action C;

String pattern1 = "##$#", pattern2 = "#$##";

String regexString = Pattern.quote(pattern1) + "(.*?)" + Pattern.quote(pattern2);
Pattern pattern = Pattern.compile(regexString);
Matcher matcher = pattern.matcher(msg);

while (matcher.find()) {
    String action = matcher.group(1);
    final String replaceAction[] = action.split("\\|\\|");
    String display = msg.replace(pattern1 + action + pattern2, replaceAction[0]);

    SpannableString ss = new SpannableString(display);
    ClickableSpan clickableSpan = new ClickableSpan() {
        @Override
        public void onClick(View textView) {
            Log.e("CLICKED", "CLICKED");
            Log.e("Action Intent", replaceAction[1]);
        }

        @Override
        public void updateDrawState(TextPaint ds) {
            super.updateDrawState(ds);
            ds.setUnderlineText(true);
        }
    };

    ss.setSpan(clickableSpan, display.indexOf(replaceAction[0]),
            display.indexOf(replaceAction[0]) + replaceAction[0].length(),
            Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
    testTV.append(ss);
    testTV.setMovementMethod(LinkMovementMethod.getInstance());
}

The above code sets the testTV with the string of

Click here to do action A
and Click ##$#here||action2#$## to do action B 
and Click ##$#here||action3#$## to do action C

Click ##$#here||action1#$## to do action A
and Click here to do action B 
and Click ##$#here||action3#$## to do action C

Click ##$#here||action1#$## to do action A
and Click ##$#here||action2#$## to do action B 
and Click here to do action C

Any help or a notion would be strongly appreciated!!!

Why don't you just use the replace API to replace the sub-string with a new string? Why is a pattern selection needed here? — Kishore Bandi
– Kishore Bandi, Commented Mar 4, 2016 at 6:48
I think I got it correct with matching and spitting. But the problem seems to be appending the text message in the textView. How do I get It correct. Just the way I've in the example above? — Samuel Robert
– Samuel Robert, Commented Mar 4, 2016 at 6:49

Andreas · Accepted Answer · 2016-03-04 16:25:30Z

2

The following regex will do it:

##\$#(.*?)\|\|action\d+#\$##

You can use the replaceAll() method like this:

str.replaceAll("##\\$#(.*?)\\|\\|action\\d+#\\$##", "$1")

See this regex101 demo.

UPDATE

The problem is that you're appending the entire msg to textTV on each iteration of find(). You need to build it up incrementally.

Something like this:

Pattern p = Pattern.compile("##\\$#(.*?)\\|\\|(.*?)#\\$##");
Matcher m = p.matcher(msg);
int prevEnd;
for (prevEnd = 0; m.find(); prevEnd = m.end()) {
    String plainText = msg.substring(prevEnd, m.start());
    String linkText = m.group(1);
    String action = m.group(2);

    SpannableString ss = new SpannableString(plainText + linkText);
    ClickableSpan clickableSpan = new ClickableSpan() {
        // code here
    };
    ss.setSpan(clickableSpan, plainText.length(), ss.length(),
               Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
    testTV.append(ss);
    testTV.setMovementMethod(LinkMovementMethod.getInstance());
}
if (prevEnd < msg.length()) {
    testTV.append(msg.substring(prevEnd));
}

edited Mar 4, 2016 at 16:25

answered Mar 4, 2016 at 6:48

Andreas

160k13 gold badges164 silver badges262 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Samuel Robert Over a year ago

I appreciate your help. But, ##\$#(.*?)\|\|action\d+#\$## is not the pattern I was looking for. B'cos, replace_string and action could be any characters in unicode. The actual pattern looks like this. ##$#replace_string||action_string#$##

Samuel Robert Over a year ago

By the way, is the argument $1 means (.*?) ?

Andreas Over a year ago

@SamuelRobert Correct. See appendReplacement()

greenPadawan · Accepted Answer · 2016-03-04 06:58:10Z

0

You can try to assign the updated value in the string msg inside the loop like msg = display; after the statement,

String display = msg.replace(pattern1 + action + pattern2, replaceAction[0]);

answered Mar 4, 2016 at 6:58

greenPadawan

1,5814 gold badges19 silver badges32 bronze badges

1 Comment

Samuel Robert Over a year ago

That did not help buddy.. :-(

Samuel Robert · Accepted Answer · 2016-03-04 10:14:37Z

0

After experimenting with it for an hour I found out that the working solution is

    String regexString = Pattern.quote(pattern1) + "(.*?)" + "\\|\\|" + "(.*?)" + Pattern.quote(pattern2);
    Pattern pattern = Pattern.compile(regexString);
    Matcher matcher = pattern.matcher(msg);

    while (matcher.find()) {
        String replace = matcher.group(1); //Replacement string
        String action = matcher.group(2);  //Action String

        msg = msg.replaceFirst(regexString, replace);
    }

Log.e ("Display Message", msg);

answered Mar 4, 2016 at 10:14

Samuel Robert

11.4k8 gold badges46 silver badges68 bronze badges

1 Comment

greenPadawan Over a year ago

This is essentially what I was suggesting you to do. The idea was that since the replacement was working just once, you replace the original message string with the one with the substituted regex. However, whatever way works for you is fine.

Collectives™ on Stack Overflow

Regular expression pattern for matching and splitting a string in java

3 Answers 3

3 Comments

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related