Example of CheckedOutputStream and CheckedInputStream in Java

package com.concretepage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.Adler32;
import java.util.zip.CheckedInputStream;
import java.util.zip.CheckedOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;
public class ZipChecksumTest {
    public static void main(String... args) throws IOException {
        String source="D:/page/file.txt";
        File sfile= new File(source);
        String dest="D:/page/file.zip";
        File dfile= new File(dest);
        FileInputStream fis= new FileInputStream(sfile);
        FileOutputStream fos= new FileOutputStream(dfile);
        //used to check checksum after writing data
        CheckedOutputStream csum = new CheckedOutputStream(fos, new Adler32());
        ZipOutputStream zos= new ZipOutputStream(csum);
        ZipEntry ze= new ZipEntry(source);
        //begins writing a new zip file and sets the the position to the start of data
        zos.putNextEntry(ze);
        byte[] buf = new byte[1024];
        int len;
        while((len=fis.read(buf))>0){
            zos.write(buf, 0, len);
        }
        fis.close();
        zos.close();
        System.out.println("checksum after writing zip:"+csum.getChecksum().getValue());
        // directory to read zip file and to write extracted file
        String dir="D:/page/";
        // read zip file as input stream
        InputStream is= new FileInputStream(dir+"file.zip");
        //used to check checksum after reading data
        CheckedInputStream chksum = new CheckedInputStream(is, new Adler32());
        //zip is read by ZipInputStream
        ZipInputStream zis= new ZipInputStream(chksum);
        // now write zip file in extracted file
        byte[] buff = new byte[1024];
        while((ze=zis.getNextEntry())!=null){
            // get file name
            fos= new FileOutputStream(ze.getName());
            int l=0;
            // write buffer to file
            while((l=zis.read(buff))>0){
                fos.write(buff,0, l);
            }
        }
        zis.close();
        System.out.println("checksum after reading zip:"+csum.getChecksum().getValue());
    }
}

checksum after writing zip:2301499827
checksum after reading zip:2301499827