How to split a String in Java

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In this post we will discuss on how to split a String using Java classes such as String, StringTokenizer and Scanner.

String.split(delimiter)

String.split(delimiter) splits the text at the given delimiter and creates an array of String objects.

String textToSplit = "1-John-Doe-35";
for (String token : textToSplit.split("-")) {
	System.out.println(token);
}

Output

1
John
Doe
35

But when you want to split the text using pipe symbol (|), you need to escape that character, because pipe symbol is a meta character used in regex. So the code will be as follows:

textToSplit = "1|John|Doe|35";
for (String token : textToSplit.split("\\|")) {
	System.out.println(token);
}

StringTokenizer(String)

  • StringTokenizer’s constructor accepts a String that needs split
  • Without delimiter, StringTokenizer breaks the String into tokens at word boundaries
  • Unlike String.split(), StringTokenizer splits the text as needed
  • Delimiters also can be specified per token basis, giving us the flexibility to change the delimiters as we proceed in the loop
  • StringTokenizer.hasMoreTokens() returns boolean signifying if more tokens available or not
  • StringTokenizer.nextToken() returns the token
textToSplit = "1 John Doe 35";
StringTokenizer tokenizer1 = new StringTokenizer(textToSplit);
while (tokenizer1.hasMoreTokens()) {
	System.out.println(tokenizer1.nextToken());
}

StringTokenizer(String, delimiters)

  • In this constructor variant StringTokenizer takes delimiters as the second parameter where you can pass one or more delimiters
textToSplit = "1|John|Doe|35";
StringTokenizer tokenizer2 = new StringTokenizer(textToSplit, "|");
while (tokenizer2.hasMoreTokens()) {
	System.out.println(tokenizer2.nextToken());
}

Scanner(String).useDelimiter(delimiter)

  • Scanner can parse a String using regex
  • Scanner provides useDelimiter method that accepts delimiter and returns Scanner again
  • Using Scanner.hasNext(), we can check for the availability of tokens
  • Scanner.next() returns a token
textToSplit = "1|John|Doe|35";
Scanner scanner = new Scanner(textToSplit).useDelimiter("\\|");
while (scanner.hasNext()) {
	System.out.println(scanner.next());
}
scanner.close();

Full Example

package com.techstackjournal;

import java.util.Scanner;
import java.util.StringTokenizer;

public class SplitString {

	public static void main(String[] args) {

		String textToSplit = "1-John-Doe-35";
		System.out.println("String.split using hyphen:");
		for (String token : textToSplit.split("-")) {
			System.out.println(token);
		}

		System.out.println();

		textToSplit = "1|John|Doe|35";
		System.out.println("String.split using pipe:");
		for (String token : textToSplit.split("\\|")) {
			System.out.println(token);
		}

		System.out.println();

		textToSplit = "1 John Doe 35";
		System.out.println("Default StringTokenizer:");
		StringTokenizer tokenizer1 = new StringTokenizer(textToSplit);
		while (tokenizer1.hasMoreTokens()) {
			System.out.println(tokenizer1.nextToken());
		}

		System.out.println();

		textToSplit = "1|John|Doe|35";
		System.out.println("StringTokenizer with delim:");
		StringTokenizer tokenizer2 = new StringTokenizer(textToSplit, "|");
		while (tokenizer2.hasMoreTokens()) {
			System.out.println(tokenizer2.nextToken());
		}

		System.out.println();

		textToSplit = "1|John|Doe|35";
		Scanner scanner = new Scanner(textToSplit).useDelimiter("\\|");
		System.out.println("Using Scanner:");
		while (scanner.hasNext()) {
			System.out.println(scanner.next());
		}
		scanner.close();
	}
}

Output:

String.split using hyphen:
1
John
Doe
35

String.split using pipe:
1
John
Doe
35

Default StringTokenizer:
1
John
Doe
35

StringTokenizer with delim:
1
John
Doe
35

Using Scanner:
1
John
Doe
35

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