Java - Insert String into another String after string pattern?

Question

I'm trying to figure out how to insert a specific string into another (or create a new one) after a certain string pattern inside the original String.

For example, given this string,

"&2This is the &6String&f."

How would I insert "&l" after all "&x" strings, such that it returns,

"&2&lThis is the &6&lString&f&l."

I tried the following using positive look-behind Regex, but it returned an empty String and I'm not sure why. The "message" variable is passed into the method.

    String[] segments = message.split("(?<=&.)");

    String newMessage = "";

    for (String s : segments){
        s.concat("&l");
        newMessage.concat(s);
    }

    System.out.print(newMessage);

Thank you!

Raman Sahasi · Accepted Answer · 2017-03-21 04:02:10Z

5

You can use:

message.replaceAll("(&.)", "$1&l")

(&.) finds pattern where an ampersand (&) is followed by anything. (&x as you've written).
$1&l says replace the captured group by the captured group itself followed by &l.

code

String message = "&2This is the &6String&f.";
String newMessage = message.replaceAll("(&.)", "$1&l"); 
System.out.println(newMessage);

result

&2&lThis is the &6&lString&f&l.

answered Mar 21, 2017 at 4:02

Raman Sahasi

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5 Comments

BlackBeltPanda Over a year ago

I'm probably doing something wrong, but that didn't work for me. It just returned the original string. I tried: String newMessage = message.replaceAll("(&.)", "$1&l"); System.out.print(newMessage);

Raman Sahasi Over a year ago

@BlackBeltPanda I've compiled this code. You can take a look at it here : Java - Insert String into another String after string pattern Are you sure you're not printing message instead of newMessage?

BlackBeltPanda Over a year ago

Yes, I tried printing both to compare them and they look the same. It outputs: Original Message: &b[&3Obsidian&aAuctions&b] &5&cAttention, an auction is beginning! New Message: &b[&3Obsidian&aAuctions&b] &5&cAttention, an auction is beginning! It's like it doesn't want to match the regex.

Raman Sahasi Over a year ago

@BlackBeltPanda can you please edit your question and provide a Minimal, Complete, and Verifiable example.

BlackBeltPanda Over a year ago

Actually just figured it out. Another method was changing the "&" to a "§" so I modified the regex to look for "(§.)" and replace with "$1§l". Thank you!

Kevin Ng · Accepted Answer · 2017-03-21 04:37:34Z

0

My answer would be similar to the one above. It just this way would be reusable and customizable in many circumstances.

public class libZ
{
    public static void main(String[] args)
    {
        String a = "&2This is the &6String&f.";
        String b = patternAdd(a, "(&.)", "&l");
        System.out.println(b);
    }

    public static String patternAdd(String input, String pattern, String addafter)
    {
        String output = input.replaceAll(pattern, "$1".concat(addafter));
        return output;
    }
}

answered Mar 21, 2017 at 4:37

Kevin Ng

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