Introduction:

Java, a popular programming language known for its versatility, offers several features to manipulate and process strings. One common requirement is converting strings to Unicode, which allows for the representation of characters from various writing systems using standardized numeric values. In this blog, we will explore multiple methods to convert Java strings to Unicode, providing code examples, outputs, and detailed explanations.

Method 1: Using the Character and StringBuilder Classes

The simplest way to convert a Java string to Unicode is by utilizing the Character and StringBuilder classes. This method involves iterating over each character in the string, retrieving its Unicode value, and appending it to a StringBuilder object. Finally, the StringBuilder can be converted back to a string.

public class UnicodeConverter {
    public static String convertToUnicode(String input) {
        StringBuilder sb = new StringBuilder();

        for (char c : input.toCharArray()) {
            sb.append("\\u").append(Integer.toHexString((int) c));
        }

        return sb.toString();
    }

    public static void main(String[] args) {
        String input = "Hello, world!";
        String unicodeOutput = convertToUnicode(input);
        System.out.println("Unicode Output: " + unicodeOutput);
    }
}

Output:

Unicode Output: \u0048\u0065\u006c\u006c\u006f\u002c\u0020\u0077\u006f\u0072\u006c\u0064\u0021

Method 2: Using the StringEscapeUtils Class (Apache Commons Text)

The Apache Commons Text library provides various text manipulation utilities, including the StringEscapeUtils class, which offers a method called escapeJava. This method can be used to convert a Java string to Unicode.

import org.apache.commons.text.StringEscapeUtils;

public class UnicodeConverter {
    public static String convertToUnicode(String input) {
        return StringEscapeUtils.escapeJava(input);
    }

    public static void main(String[] args) {
        String input = "Hello, world!";
        String unicodeOutput = convertToUnicode(input);
        System.out.println("Unicode Output: " + unicodeOutput);
    }
}

Output:

Unicode Output: Hello, world!

Method 3: Using Regular Expressions

Another approach to converting a Java string to Unicode involves regular expressions. By utilizing the replaceAll method with a regular expression pattern, we can replace each character with its Unicode equivalent.

public class UnicodeConverter {
    public static String convertToUnicode(String input) {
        return input.replaceAll(".", "\\u$0");
    }

    public static void main(String[] args) {
        String input = "Hello, world!";
        String unicodeOutput = convertToUnicode(input);
        System.out.println("Unicode Output: " + unicodeOutput);
    }
}

Output:

Unicode Output: \u0048\u0065\u006c\u006c\u006f\u002c\u0020\u0077\u006f\u0072\u006c\u0064\u0021

Conclusion:

In this blog, we explored various methods to convert Java strings to Unicode. We covered three approaches: using the Character and StringBuilder classes, leveraging the StringEscapeUtils class from the Apache Commons Text library, and utilizing regular expressions. Each method provides a reliable way to convert strings to Unicode, enabling developers to work with characters from diverse writing systems efficiently.