CharsetEncoder encode(CharBuffer in) method in Java with Examples

The java.nio.charset.The CharsetEncoder package includes an encode(CharBuffer input) method by the standard. CharsetEncoder, which converts the remaining characters in a single input character buffer into an entirely new allocated byte-buffer. The complete encoding process is implemented by the encode() method alone. If the operation is currently taking place, the corresponding method shouldn't be called.

When text data needs to be converted into binary format for transmission or storage, this method is very effective because it ensures that the character data follows the selected encoding standard (e.g., ISO-8859-1, UTF-8). After processing the input CharBuffer, the encode method yields a ByteBuffer with the encoded bytes in it.

Syntax:

Parameters: The method takes as input a required argument that defines the input character buffer.

Return Value: The function returns the result of the encoding process in a newly allocated byte buffer.

Error and Exceptions:

There are four exceptions raised by the function, which are explained as follows:

IllegalStateException: If an encoding method is currently in progress, it is thrown.

MalformedInputException: If the current malformed-input action is CodingErrorAction.REPORT and the character sequence beginning at the current location in the input buffer is not a valid sixteen-bit Unicode sequence; it is thrown.

UnmappableCharacterException: If the current unmappable-character action is CodingErrorAction.REPORT and the character sequence beginning at the current location of the input buffer cannot be mapped to an equivalent byte sequence; it is thrown.

Example 1:

For handling character-to-byte conversion, more specifically, the UTF-8 encoding scheme, the code makes use of the CharsetEncoder class. Charset.forName("UTF8").newEncoder() is used to initialize an encoder that creates a CharBuffer for encoding using the CharBuffer.wrap() method and newEncoder(). The data of the CharBuffer is transformed into a ByteBuffer, which holds the encoded bytes, by using the encode method. Text processing in certain encodings requires compatibility between encoded byte representations and character data, which is ensured by this method.

Implementation:

FileName: CharsetCharBufferExample1.java

Output:

 java.nio.HeapByteBuffer[pos=0 lim=11 cap=12] 

Example 2:

In the implementation of CharsetEncoder, the code illustrates how to encode character data using UTF-16 character encoding into bytes. It is used to set up the encoder using Charset.forName("UTF16").To prepare the string data as a CharBuffer, use CharBuffer.wrap() and newEncoder(). The encoding method essentially translates characters into a byte sequence according to the UTF-16 standard by converting the CharBuffer into a ByteBuffer. UTF-8 uses 1 to 4 bytes per character, which makes it more space-efficient for ASCII letters. In contrast, UTF-16 offers consistent encoding for a larger range of text by using 2 bytes for most characters. However, it may need 4 bytes for extra characters. This method makes sure that text is handled precisely in a particular encoding, which makes things like data transfer and storage in encoded formats easier.

Implementation:

FileName: CharsetCharBufferExample2.java

Output:

 java.nio.HeapByteBuffer[pos=0 lim=24 cap=45]