Java Program to Read and Print All Files From a Zip File

A ZIP file can contain multiple files and directories compressed into a single archive. Java provides classes from the java.util.zip package to read ZIP archives and access the entries stored inside them.

• ZipInputStream is used to read entries from a ZIP file sequentially.
• ZipEntry represents an individual file or directory stored inside the ZIP archive.

Steps to read and print files from a ZIP file

1. Take the ZIP file path as input.
2. Create a ZipInputStream for the specified ZIP file.
3. Read each ZipEntry using getNextEntry().
4. Print the name of every entry until all entries are processed.

Approach

• Read the location of the ZIP file from the user.
• Pass the file path to a method that processes the ZIP archive.
• Use ZipInputStream to access each entry in the archive.
• Use getNextEntry() to move through the files one by one.
• Print the name of each file or directory present in the ZIP file.
• Handle FileNotFoundException if the specified ZIP file does not exist and IOException for other file-related errors.

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Scanner;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class GFG {

    // Function to read and print the file names.
    public void printFileContent(String filePath)
    {

        // Creating objects for the classes and
        // initializing them to null
        FileInputStream fs = null;
        ZipInputStream Zs = null;
        ZipEntry ze = null;

        // Try block to handle if exception occurs
        try {

            // Display message when program compiles
            // successfully
            System.out.println(
                "Files in the zip are as follows: ");

            fs = new FileInputStream(filePath);
            Zs = new ZipInputStream(
                new BufferedInputStream(fs));

            // Loop to read and print the zip file name till
            // the end
            while ((ze = Zs.getNextEntry()) != null) {
                System.out.println(ze.getName());
            }

            // Closing the file connection
            Zs.close();
        }

        // Catch block to handle if exception related
        // to file handling occurs
        catch (FileNotFoundException fe) {

            // Print the line line and exception
            // of the program where it occurred
            fe.printStackTrace();
        }

        // Catch block to handle generic exceptions
        catch (IOException ie) {

            // Print the line line and exception
            // of the program where it occurred
            ie.printStackTrace();
        }
    }

    // Main driver method
    public static void main(String[] args)
    {

        // Creating an object of the file
        GFG zf = new GFG();

        // Taking input of the zip file from local directory
        // Name of the zip file to be read should be entered
        Scanner sc = new Scanner(System.in);

        // Display message asking user to enter
        // zip file local directory
        System.out.println(
            "Enter the location of the zip file: ");
        String str = sc.nextLine();

        // Print the zip files(compressed files)
        zf.printFileContent(str);
    }
}

Output

For example, if the ZIP file is located at:

/Users/mayanksolanki/Desktop/Job/Geekathon/Archive.zip

and contains several files, the output will be:

Enter the location of the zip file:
/Users/mayanksolanki/Desktop/Job/Geekathon/Archive.zip

Files in the zip are as follows:
Q1.Vaidik.Try2.png
__MACOSX/_Q1.Vaidik.Try2.png
Q2.Vaidik.Ry1.Output.png
__MACOSX/_Q2.Vaidik.Ry1.Output.png
Q2.Vaidik.Try2.png
__MACOSX/_Q2.Vaidik.Try2.png
Q4.Vaidik.OSI.png
__MACOSX/_Q4.Vaidik.OSI.png
Q12Vaidik.Try1.png
__MACOSX/_Q12Vaidik.Try1.png

Explanation

• FileInputStream opens the ZIP file from the specified location.
• BufferedInputStream provides buffered access to the file data.
• ZipInputStream reads the ZIP archive and provides access to its entries.
• getNextEntry() returns the next ZipEntry in the archive. It returns null when there are no more entries.
• getName() returns the name and path of the current entry.
• close() closes the ZIP input stream after all entries have been processed.
• If the specified file does not exist, FileNotFoundException is handled by the catch block.

Note: This program prints the names of the files and directories inside the ZIP archive. It does not extract or print the actual contents of those files.

Advantages

• Simple: The program can list all entries in a ZIP file using only a few Java classes.
• No extraction required: Files can be listed without first extracting the ZIP archive.
• Sequential processing: getNextEntry() allows the entries to be processed one by one.
• Built-in support: ZIP handling is available through Java's standard library.

Limitations

• Does not extract files: The program only displays entry names.
• No file content is displayed: It does not read or print the actual contents of the files inside the ZIP.
• Exception handling is required: Missing files or other I/O problems can cause exceptions.
• ZIP-specific: ZipInputStream is designed for ZIP archives and cannot directly process other archive formats.