将使用java.util.zip创建的zip大小与使用java的原始文件夹大小进行比较

Question

I have just created a Zip file using java.util.zip. Now I would want to check if the ZIP created is correct and the uncompressed size of the ZIP file is equal to the actual folders that I have zipped.

I know of a method ZipFile.isValid() which returns true if all the headers in the ZIP are correct. Doesn't solve my problem though.

Thanks :)

Answer 1

Unzip the *.zip file, iterate over each ZipEntry element, sum each ZipEntry.getSize(). Compare this to the sum of the file sizes you zipped. Alternatively (if you don't trust the ZipEntry headers for some reason) unzip each ZipEntry, counting the bytes, but discarding them. You might do either of these things say, as a quick check of your zip code, or maybe even in a unit test.

You can iterate over the ZipEntry's thusly:

zipInStream = new ZipInputStream(new FileInputStream(zipFile));
ZipEntry zipEntry;
while ((zipEntry = zipInStream.getNextJarEntry()) != null) {
    String entryName = zipEntry.getName();
    ....
}

Answer 2

Checking if the ZIP file is created correctly

if (myZipFile.isValid())
{
    // The file has been created successfully
}

Knowing the Length of the directory and the file.

File dir = new File("path/to/the/directory/");
int size = dir.length();

File zip = new File("path/to/zipfile.zip");
int zipSize = zip.length();

Now you can compare them.