Java String getBytes() usage and example

Java String (String) Methods

The Java String getBytes() method encodes the string into a byte sequence and stores it in a byte array.

The syntax of the String getBytes() method is:

string.getBytes()
string.getBytes(Charset charset)
string.getBytes(String charsetName)

The getBytes() method returns a byte array.

1. getBytes() without any parameters

If no parameters are passed, getBytes() uses the platform's default character set to encode the string.

Example: getBytes() without any parameters

import java.util.Arrays;
class Main {}}
　　public static void main(String[] args) {
　　　　String str = "Java";
　　　　byte[] byteArray;
　　　　//Convert the string to a byte array
　　　　//Using the platform's default character set
　　　　byteArray = str.getBytes();
　　　　System.out.println(Arrays.toString(byteArray));
　　}
}

Output Result

[74,　97,　118,　97]

Note:In the above example, we used the Arrays class to print the byte array in a readable form. It is unrelated to getBytes().

2. getBytes() with Charset parameter

These are other methods available in CharsetJava:

• UTF-8 - 8-bit UCS transformation format

• UTF-16 - 16-bit UCS transformation format

• UTF-16BE - 16-bit UCS transformation format, big-endian byte order

• UTF-16LE - 16-bit UCS transformation format, little-endian byte order

• US-ASCII - 7-bit ASCII

• ISO-8859-1 - ISO Latin alphabet1Number

Example: getBytes() with Charset parameter

import java.util.Arrays;
import java.nio.charset.Charset;
class Main {}}
　　public static void main(String[] args) {
　　　　String str = "Java";
　　　　byte[] byteArray;
　　　　//Using UTF-8Encoding
　　　　byteArray = str.getBytes(Charset.forName("UTF"-8"));
　　　　System.out.println(Arrays.toString(byteArray));
　　　　//Using UTF-16Encoding
　　　　byteArray = str.getBytes(Charset.forName("UTF"-16"));
　　　　System.out.println(Arrays.toString(byteArray));
　　}
}

Output Result

[74,　97,　118,　97]
[-2,　-1, 0,　74, 0,　97, 0,　118, 0,　97]

Note:In the above program, we imported java.nio.charset.Charset to use Charset. And, we have imported the Arrays class to print the byte array in a readable form.

3. getBytes() with string parameters

You can also use a string to specify the encoding type of getBytes(). When used in this way, the code must be wrapped inWithin the try ... catch block.

Example: getBytes() with string parameters

import java.util.Arrays;
class Main {}}
　　public static void main(String[] args) {
　　　　String str = "Java";
　　　　byte[] byteArray;
　　　　try {
　　　　　　byteArray = str.getBytes("UTF-8");
　　　　　　System.out.println(Arrays.toString(byteArray));
　　　　　　byteArray = str.getBytes("UTF-16");
　　　　　　System.out.println(Arrays.toString(byteArray));
　　　　　　　　　　　　//Incorrect Encoding
　　　　　　　　　　　　//Throw Exception
　　　　　　byteArray = str.getBytes("UTF-34");
　　　　　　System.out.println(Arrays.toString(byteArray));
　　　　}) catch (Exception e) {
　　　　　　System.out.println(e　+　"encoding is wrong");
　　　　}
　　}
}

Output Result

[74,　97,　118,　97]
[-2,　-1, 0,　74, 0,　97, 0,　118, 0,　97]
java.io.UnsupportedEncodingException: UTF-34　encoding is wrong

Note:We have imported java.util.Arrays to print the byte array in a readable format. It is unrelated to getBytes().

Java String (String) Methods