zip4J exception un-zipping password protected zip file

Question

I am tasked with using open source 'zip4jlibrary for creating and unzipping of password-protected zip files. Method parameters will bebyte[]of file content and password and it should return a byte array as output (unzipped or zipped content), noFile system` involved. I tried the below code segment which throws 'net.lingala.zip4j.exception.ZipException: File does not exist: \test\Test.txt' at line "zipFile.addFiles(filesToAdd, zipParameters);" What I am missing here? Exception in thread "main" net.lingala.zip4j.exception.ZipException: File does not exist: \test\ZipThis.txt at net.lingala.zip4j.util.FileUtils.assertFileExists(FileUtils.java:526) at net.lingala.zip4j.util.FileUtils.assertFilesExist(FileUtils.java:359) at net.lingala.zip4j.tasks.AbstractAddFileToZipTask.addFilesToZip(AbstractAddFileToZipTask.java:62) at net.lingala.zip4j.tasks.AddFilesToZipTask.executeTask(AddFilesToZipTask.java:27) at net.lingala.zip4j.tasks.AddFilesToZipTask.executeTask(AddFilesToZipTask.java:15) at net.lingala.zip4j.tasks.AsyncZipTask.performTaskWithErrorHandling(AsyncZipTask.java:51) at net.lingala.zip4j.tasks.AsyncZipTask.execute(AsyncZipTask.java:45) at net.lingala.zip4j.ZipFile.addFiles(ZipFile.java:318) at net.lingala.zip4j.ZipFile.addFile(ZipFile.java:275)

public class ExtractZip {

    public static byte[] extractWithZipInputStream(byte[] inputArr, char[] password) {
        LocalFileHeader localFileHeader;
        int readLen;
        InputStream byteStream = new ByteArrayInputStream(inputArr);
        byte[] readBuffer = new byte[4096];
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ZipInputStream zipInputStream = new ZipInputStream(byteStream, password);

        try {
            while ((localFileHeader = zipInputStream.getNextEntry()) != null) {
                while ((readLen = zipInputStream.read(readBuffer)) != -1) {
                    bos.write(readBuffer, 0, readLen);
                }
                break;
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                bos.close();
            } catch (Exception e) {
            }
            try {
                zipInputStream.close();
            } catch (Exception e) {
            }
        }
        return bos.toByteArray();
    }

    public static void main(String[] args) {
        FileOutputStream fos;
        byte[] inputBuffer = new byte[1024];

        try {
            ZipParameters zipParameters = new ZipParameters();
            zipParameters.setEncryptFiles(true);
            zipParameters.setEncryptionMethod(EncryptionMethod.ZIP_STANDARD);
            List<File> filesToAdd = Arrays.asList(new File("/test/ZipThis.txt"));
            ZipFile zipFile = new ZipFile("/test/Template_Zip.zip", "abc123".toCharArray());
            zipFile.addFiles(filesToAdd, zipParameters);
            inputBuffer = Files.readAllBytes(Paths.get("/test/Template_Zip.zip"));
            byte[] outputArr = ExtractZip.extractWithZipInputStream(inputBuffer, "abc123".toCharArray());

            //Test if you can create a file using with this byte array
            File unZipped = new File("/test/unzipped/temp");
            fos = new FileOutputStream(unZipped);
            fos.write(outputArr[0]);
            fos.flush();
            fos.close();
            zipFile.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

Answer 1

Looks good to me. Just try to set absolute path instead of the relative ones. E.g.

ZipFile zipFile = new ZipFile("c:/test/Template_Zip.zip", "abc123".toCharArray());

All other such places as well. I think your problem will go away.

P.S. It's better to use try with resources instead of what you do.

---

import net.lingala.zip4j.ZipFile;
import net.lingala.zip4j.io.inputstream.ZipInputStream;
import net.lingala.zip4j.model.LocalFileHeader;
import net.lingala.zip4j.model.ZipParameters;
import net.lingala.zip4j.model.enums.EncryptionMethod;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.List;

public class ExtractZip {

    public static byte[] extractWithZipInputStream(byte[] buf, char[] password) throws IOException {
        try (InputStream byteStream = new ByteArrayInputStream(buf);
             ZipInputStream zipInputStream = new ZipInputStream(byteStream, password);
             ByteArrayOutputStream bos = new ByteArrayOutputStream()) {

            LocalFileHeader localFileHeader = zipInputStream.getNextEntry();

            if (localFileHeader == null)
                return new byte[0];

            int readLen;
            byte[] readBuffer = new byte[4096];

            while ((readLen = zipInputStream.read(readBuffer)) != -1) {
                bos.write(readBuffer, 0, readLen);
            }

            return bos.toByteArray();
        }
    }

    public static void main(String[] args) throws IOException {
        ZipParameters zipParameters = new ZipParameters();
        zipParameters.setEncryptFiles(true);
        zipParameters.setEncryptionMethod(EncryptionMethod.ZIP_STANDARD);
        List<File> filesToAdd = Arrays.asList(new File("e:/foo.txt"));
        ZipFile zipFile = new ZipFile("e:/Template_Zip.zip", "abc123".toCharArray());
        zipFile.addFiles(filesToAdd, zipParameters);
        byte[] buf = Files.readAllBytes(Paths.get("e:/Template_Zip.zip"));
        buf = extractWithZipInputStream(buf, "abc123".toCharArray());

        try (FileOutputStream fos = new FileOutputStream(new File("e:/fooZip.txt"))) {
            fos.write(buf);
        }
    }

}

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