Java

Compress and Decompress Hex String

See more Compression Examples

Imagine we have data represented as a hex string. This example demonstrates how to decode, compress, and re-encode to a smaller hex string representing the compressed data. An even better choice is to re-encode to a more compact encoding such as base64.

Note: This example requires Chilkat v9.5.0.66 or greater.

Chilkat2 Java

import com.chilkatsoft.chilkat2.BinData;
import com.chilkatsoft.chilkat2.Compression;

public class ChilkatExample {

    public static void main(String[] args) {
        // This example assumes the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        String strHex = "54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A0D0A";

        Compression compress = new Compression();
        compress.setAlgorithm("deflate");

        BinData binDat = new BinData();
        // Load the hex string into a BinData object.
        // This decodes the hexidecimal. The decoded bytes will be contained in the BinData.
        binDat.appendEncoded(strHex, "hex");

        // Compress the BinData.
        compress.compressBd(binDat);

        // Get the compressed data in hex format:
        String compressedHex = binDat.getEncoded("hex");
        System.out.println("compressed hex:");
        System.out.println(compressedHex);

        // The compressed hex is: 0BC94855282CCD4CCE56482ACA2FCF5348CBAF50C82ACD2D484D51C82F4B2D522801CAE72456552AA4E4A7EBF172850C61E5BC5C00

        // Even better, get the compressed data in base64 format:
        // (base64url and modbase64 are other valid choices...)
        String compressedBase64 = binDat.getEncoded("base64");
        System.out.println("compressed base64:");
        System.out.println(compressedBase64);

        // The compressed base64 is: C8lIVSgszUzOVkgqyi/PU0jLr1DIKs0tSE1RyC9LLVIoAcrnJFZVKqTkp+vxcoUMYeW8XAA=

        // Now decompress:
        binDat.clear();
        binDat.appendEncoded(compressedHex, "hex");
        compress.decompressBd(binDat);

        String decompressedHex = binDat.getEncoded("hex");
        System.out.println("decompressed hex:");
        System.out.println(decompressedHex);

        // The output is the original hex string:
        // 54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A0D0A
    }
}