CODEWITHSUNDEEP
java
Atish Bundhe
Atish Bundhe

Reputation: 545

StringTokenizer breaking string on wrong delimiter

I am using the StringTokenizer in java to tokenize the string as shown in following is my code

import java.util.StringTokenizer;

public class Test {
    public static void main(String[] args) {
        String str = "key1@@@@@val1#####key2@@@@@val2#####key3@@@@@val3#####key4@@@@@val4###val4###val4#####key5@@@@@val5";

        StringTokenizer st = new StringTokenizer(str,"#####");
        while(st.hasMoreTokens()){
            System.out.println(st.nextElement());
        }
    }

}

The output is

key1@@@@@val1

key2@@@@@val2

key3@@@@@val3

key4@@@@@val4

val4

val4

key5@@@@@val5

Actually the delimiter is "#####" so why it is breaking at "###"

Expected output

key1@@@@@val1

key2@@@@@val2

key3@@@@@val3

key4@@@@@val4###val4###val4

key5@@@@@val5

I know i can do it by using another delimiter than ### but I want to know exact reason behind this.

Upvotes: 0

Views: 522

Answers (4)

Vish
Vish

Reputation: 842

If you want multiple delimiters to be used for breaking string, you can use the following as the example. 

    String msg = "http://192.173.15.36:8084/";
    StringTokenizer st = new StringTokenizer(msg, "://.");
    while (st.hasMoreTokens()) {
        System.out.println(st.nextToken());
    }

More details here

Upvotes: 0

Mustafa sabir
Mustafa sabir

Reputation: 4360

The delimeter is a character which is not considered as a token, so also mentioning # as delimeter it will give you the same output. Quoting from java docs

The characters in the delim argument are the delimiters for separating tokens. Delimiter characters themselves will not be treated as tokens.

Hence any character mentioned as delimeter will completely be ignored and the remaining String will be tokenised.

And quoting from same source as an better alternative for your purpose:-

StringTokenizer is a legacy class that is retained for compatibility reasons although its use is discouraged in new code. It is recommended that anyone seeking this functionality use the split method of String or the java.util.regex package instead.

Use string.split("#####")

Upvotes: 2

antonio
antonio

Reputation: 18242

In StringTokenizer you specify the characters that are going to be used as delimiters.

Your line

StringTokenizer st = new StringTokenizer(str, "#####");

is equivalent to

StringTokenizer st = new StringTokenizer(str, "#");

To understand the case you can do

StringTokenizer st = new StringTokenizer(str, "#@");

Upvotes: 2

amit
amit

Reputation: 178421

The StringTokenizer splits according to each of the characters in the provided delim argument.

In your case, you generate a StringTokenizer that splits according to '#' only.

From the java docs of StringTokenizer(String,String)

.... The characters in the delim argument are the delimiters for separating tokens. Delimiter characters themselves will not be treated as tokens....

Upvotes: 3

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