CharsetEncoder isLegalReplacement() method in Java with Examples

The isLegalReplacement() method is a built-in method of the java.nio.charset.CharsetEncoder gives us an indication on whether or not the given byte array is a legal replacement value for this encoder. A replacement is legal if it is possible to decode the replacement into one or more sixteen-bit Unicode characters.

Syntax:

public boolean isLegalReplacement(byte[] repl)

Parameters: The function accepts a mandatory parameter repl which specifies the byte array to be tested.

Return Value: The function returns a boolean value. It returns true if the byte array is a legal replacement of the encoder, else it returns false.

Below is the implementation of the above function:

Program 1:

// Java program to implement
// the above function
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;

public class Main {
    public static void main(String[] args) throws Exception
    {
        // Gets the encoder
        CharsetEncoder encoder = Charset.forName("UTF8").newEncoder();

        // Prints if legal or not
        System.out.println(encoder.isLegalReplacement(new byte[] {}));
    }
}

Output:

true

Program 2:

// Java program to implement
// the above function
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;

public class Main {
    public static void main(String[] args) throws Exception
    {
        // Gets the encoder
        CharsetEncoder encoder = Charset.forName("US-ASCII").newEncoder();

        // Prints if legal or not
        System.out.println(encoder.isLegalReplacement(new byte[] {}));
    }
}

Output:

true

Reference: https://docs.oracle.com/javase/10/docs/api/java/nio/charset/CharsetEncoder.html#isLegalReplacement(byte%5B%5D)