How do I split up string using regular expression?

By Wayan in Regex 0 Comment

This code snippet uses the java.util.regex.Pattern.split() method to split-up input string separated by commas or whitespaces (spaces, tabs, new lines, carriage returns, form feeds).

package org.kodejava.regex;

import java.util.regex.Pattern;

public class RegexSplitExample {
    public static void main(String[] args) {
        // Pattern for finding commas, whitespaces (spaces, tabs, new lines,
        // carriage returns, form feeds).
        String pattern = "[,\\s]+";
        String colors = """
                Red,White, Blue   Green        Yellow,
                Orange Pink""";

        Pattern splitter = Pattern.compile(pattern);
        String[] results = splitter.split(colors);

        for (String color : results) {
            System.out.format("Color = \"%s\"%n", color);
        }
    }
}

The result of our code snippet is:

Color = "Red"
Color = "White"
Color = "Blue"
Color = "Green"
Color = "Yellow"
Color = "Orange"
Color = "Pink"

How do I split a string using Scanner class?

By Wayan in Core API, Util Package 0 Comment

Instead of using the StringTokenizer class or the String.split() method we can use the java.util.Scanner class to split a string.

package org.kodejava.util;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class ScannerTokenDemo {
    public static void main(String[] args) {
        // This file contains some data as follows:
        // a, b, c, d
        // e, f, g, h
        // i, j, k, l
        File file = new File("data.txt");
        try {
            // Here we use the Scanner class to read file content line-by-line.
            Scanner scanner = new Scanner(file);
            while (scanner.hasNextLine()) {
                String line = scanner.nextLine();

                // From the above line of code we got a line from the file
                // content. Now we want to split the line with comma as the 
                // character delimiter.
                Scanner lineScanner = new Scanner(line);
                lineScanner.useDelimiter(",");
                while (lineScanner.hasNext()) {
                    // Get each split data from the Scanner object and print
                    // the value.
                    String part = lineScanner.next();
                    System.out.print(part + ", ");
                }                
                System.out.println();
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
}

How do I split a string?

By Wayan in Core API, Lang Package 0 Comment

Prior to Java 1.4 we use java.util.StringTokenizer class to split a tokenized string, for example a comma separated string. Starting from Java 1.4 and later the java.lang.String class introduce a String.split(String regex) method that simplify this process.

Below is a code snippet how to do it.

package org.kodejava.lang;

import java.util.Arrays;

public class StringSplit {
    public static void main(String[] args) {
        String data = "1,Diego Maradona,Footballer,Argentina";
        String[] items = data.split(",");

        // Iterates the array to print it out.
        for (String item : items) {
            System.out.println("item = " + item);
        }

        // Or simply use Arrays.toString() when print it out.
        System.out.println("item = " + Arrays.toString(items));
    }
}

The result of the code snippet:

item = 1
item = Diego Maradona
item = Footballer
item = Argentina
item = [1, Diego Maradona, Footballer, Argentina]

How do I use StringTokenizer to split a string?

By Wayan in Core API, Util Package 0 Comment

The code below is an example of using StringTokenizer to split a string. In the current JDK this class is discouraged to be used, use the String.split(...) method instead or using the new java.util.regex package.

package org.kodejava.util;

import java.util.StringTokenizer;

public class StringTokenizerExample {
    public static void main(String[] args) {
        StringTokenizer st =
            new StringTokenizer("A StringTokenizer sample");

        // get how many tokens inside st object
        System.out.println("Tokens count: " + st.countTokens());

        // iterate st object to get more tokens from it
        while (st.hasMoreElements()) {
            String token = st.nextElement().toString();
            System.out.println("Token = " + token);
        }

        // split a date string using a forward slash as delimiter
        st = new StringTokenizer("2021/09/14", "/");
        while (st.hasMoreElements()) {
            String token = st.nextToken();
            System.out.println("Token = " + token);
        }
    }
}

Here is the result of this sample code:

Tokens count: 3
Token = A
Token = StringTokenizer
Token = sample
Token = 2021
Token = 09
Token = 14