Deflater setLevel() function in Java with examples

The setLevel() function of the Deflater class in java.util.zip sets the current compression level to the specified value. The compression level is an integer value from 0 to 9.
Function Signature:

public void setLevel(int level)

Syntax:

d.setLevel(int);

Parameter: The function requires an integer value which is the specified compression value

Return Type: The function does not return any value.

Exception: The function throws IllegalArgumentException if the compression level is invalid.

Some constant values for deflater levels :

BEST_COMPRESSION : compression level for best compression

BEST_SPEED : Compression level for fastest compression.

DEFAULT_COMPRESSION : Default compression level.

NO_COMPRESSION : Compression level for no compression.

Example 1:

// Java program to describe the use
// of setLevel() function

import java.util.zip.*;
import java.io.UnsupportedEncodingException;

class GFG {

    // Function to compress the string to the given level
    static void compression(int level, String text)
        throws UnsupportedEncodingException
    {
        // deflater
        Deflater d = new Deflater(level);

        // set the Input for deflator
        d.setInput(text.getBytes("UTF-8"));

        // finish
        d.finish();

        // output bytes
        byte output[] = new byte[1024];

        // compress the data
        int size = d.deflate(output);

        // compressed String
        System.out.println("Compressed String with level ="
                           + level + " :"
                           + new String(output)
                           + "\n Size " + size);

        d.end();
    }

    // Driver code
    public static void main(String args[])
        throws UnsupportedEncodingException
    {

        // get the text
        String pattern = "GeeksforGeeks", text = "";

        // generate the text
        for (int i = 0; i < 4; i++)
            text += pattern;

        // original String
        System.out.println("Original String :" + text
                           + "\n Size " + text.length());

        // default
        compression(Deflater.DEFAULT_COMPRESSION, text);

        // no compression
        compression(Deflater.NO_COMPRESSION, text);

        // Best compression
        compression(Deflater.BEST_COMPRESSION, text);

        // Best Speed
        compression(Deflater.BEST_SPEED, text);
    }
}

Output:

Original String :GeeksforGeeksGeeksforGeeksGeeksforGeeksGeeksforGeeks
 Size 52
Compressed String with level =-1 :x?sOM?.N?/r???q??
 Size 21
Compressed String with level =0 :x4??GeeksforGeeksGeeksforGeeksGeeksforGeeksGeeksforGeeks??
 Size 63
Compressed String with level =9 :x?sOM?.N?/r???q??
 Size 21
Compressed String with level =1 :xsOM?.N?/r?`?0??
 Size 22

Reference: https://docs.oracle.com/javase/7/docs/api/java/util/zip/Deflater.html#setLevel()