Examples of CharEncoder Class
Example 1: Basic use of CharsetEncoder
In this example, the input string is encoded into bytes using the CharsetEncoder with UTF-8 character encoding.
It covers on how to construct a CharsetEncoder, encode the characters, place the input text within a CharBuffer, then output the data that has been encoded. It has basic error handling to address any issues that may come up during the encoding process.
Java
// Java Program to construct a // CharsetEncoder using CharBuffer import java.nio.*; import java.nio.charset.*; //Driver class public class Main { // Main method public static void main(String[] args){ // Create a Charset Charset ch = Charset.forName("UTF-8"); // Initialize a CharsetEncoder CharsetEncoder ec = ch.newEncoder(); // Input string String str = "CharsetEncoder Example"; // Wrap the input text in a CharBuffer CharBuffer charBuffer = CharBuffer.wrap(str); try { // Encode the characters ByteBuffer bf = ec.encode(charBuffer); // Print the encoded data String ans = new String(bf.array()); System.out.println(ans); } catch (Exception e) { // Handle the exception e.printStackTrace(); } } } |
Output:
CharsetEncoder Example
Example 2: Error Handling
The UTF-8 character encoding can encode only the characters that lie within the Unicode standard. There are some special characters or symbols that cannot be recognized by this encoding technique. In order to prevent problems, the errors need to be handled using some methods. In the below given example, we have given an input string which contains a special symbol ‘Ω’, that is not mappable using UTF-8. We use the ‘onUnmappableCharacter‘ and ‘CodingErrorAction.REPLACE‘ methods to replace these unmappable characters with any different character.
In the code below, whenever we encounter ‘Ω’, it is replaced by ‘?‘ which indicates that the special symbol is replaced with a fallback character for error handling.
Java
// Java Program for Error handling // Using onUnmappableCharacter import java.nio.*; import java.nio.charset.*; //Driver Class public class Main { //Main method public static void main(String[] args){ // Create a Charset Charset ch = Charset.forName("UTF-8"); // Initialize a CharsetEncoder CharsetEncoder ec = ch.newEncoder(); // Input string (with Ω as an unmappable character) String str = "Charset Ω Encoder"; // Handle the error by replacing the unmappable // character with a question mark ec.onUnmappableCharacter(CodingErrorAction.REPLACE); ec.replaceWith("?".getBytes()); // Wrap the string into a CharBuffer CharBuffer cb = CharBuffer.wrap(str); try { // Encode the characters ByteBuffer bf = ec.encode(cb); // Convert the ByteBuffer to a String String ans = new String(bf.array()); System.out.println("Encoded String: " + ans); } catch (Exception e) { // Handle the exception System.err.println("Error: " + e.getMessage()); } } } |
Output:
Encoded String: Charset ? Encoder
java.nio.charset.CharsetEncoder Class in Java
For the purpose of character encoding and decoding, java offers a number of classes in the ‘java.nio.charset’ package. The ‘CharsetEncoder’ class of this package performs the important task of encoding. In this article, let us understand this class, its syntax, different methods, and some examples of error handling and optimization techniques.
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