java.util.zip.ZipInputStream.getNextEntry() Method Example

The java.util.zip.ZipInputStream.getNextEntry() method reads the next ZIP file entry and positions the stream at the beginning of the entry data.
Following is the declaration for java.util.zip.ZipInputStream.getNextEntry() method.
public ZipEntry getNextEntry()
   throws IOException

the next ZIP file entry, or null if there are no more entries.
ZipException  − if a ZIP file error has occurred.
ZipException  − if a ZIP file error has occurred.
IOException  − if an I/O error has occurred.
IOException  − if an I/O error has occurred.
Create a file Hello.txt in D:> test >  directory with the following content.
This is an example.

The following example shows the usage of java.util.zip.ZipInputStream.getNextEntry() method.
package com.tutorialspoint;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Date;
import java.util.zip.Adler32;
import java.util.zip.CheckedOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;

public class ZipInputStreamDemo {
   private static String SOURCE_FILE = "D:\\test\\Hello.txt";
   private static String TARGET_FILE = "D:\\test\\Hello.zip";

   public static void main(String[] args) {
      try {
         createZipFile();
         readZipFile();
      } catch(IOException ioe) {
         System.out.println("IOException : " + ioe);
      }
   }

   private static void createZipFile() throws IOException{
      FileOutputStream fout = new FileOutputStream(TARGET_FILE);
      CheckedOutputStream checksum = new CheckedOutputStream(fout, new Adler32());
      ZipOutputStream zout = new ZipOutputStream(checksum);

      FileInputStream fin = new FileInputStream(SOURCE_FILE);
      ZipEntry zipEntry = new ZipEntry(SOURCE_FILE);
      zout.putNextEntry(zipEntry);
      int length;
      byte[] buffer = new byte[1024];
      while((length = fin.read(buffer)) > 0) {
         zout.write(buffer, 0, length);
      }

      zout.closeEntry();
      fin.close();
      zout.close();
   }

   private static void readZipFile() throws IOException{
      ZipInputStream zin = new ZipInputStream(new FileInputStream(TARGET_FILE)); 

      ZipEntry entry;
      while((entry = zin.getNextEntry())!=null){
         System.out.printf("File: %s Modified on %TD %n", 
         entry.getName(), new Date(entry.getTime()));
         extractFile(entry, zin); 
         System.out.printf("Zip file %s extracted successfully.", SOURCE_FILE);
         zin.closeEntry();
      }
      zin.close();
   }

   private static void extractFile(final ZipEntry entry, ZipInputStream is) 
      throws IOException {
      FileOutputStream fos = null; 
      try { 
         fos = new FileOutputStream(entry.getName()); 
         while(is.available() != 0){
            fos.write(is.read()); 
         }
      } catch (IOException ioex) { 
         fos.close(); 
      } 
   }
}
Let us compile and run the above program, this will produce the following result −
File: D:\test\Hello.txt Modified on 05/22/17 
Zip file D:\test\Hello.txt extracted successfully.

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