AndroidZip

A zip explorer library for android that uses DocumentFile object as its source. It uses my StreamZip library as its base. Its functionalities are similar to the standard java ZipFile class.

Import

Add JitPack repository to your project level build.gradle file

...

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

Or, in newer android projects, if you need to add the repository in settings.gradle file...

...

dependencyResolutionManagement {
    ...
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

Finally, add these two dependencies to your app/module level build.gradle file

...

dependencies {
    ...
    implementation 'com.github.buggysofts-com:StreamZip:v1.0.6'
    implementation 'com.github.buggysofts-com:AndroidZip:v1.0.6'
}

And you are done importing the library.

Sample codes

To create an instance do something like...

AndroidZip zip = null;
try {
    zip = new AndroidZip(MainActivity.this, documentFile);
} catch (Exception e) {
    e.printStackTrace();
} finally {
    if(zip != null){
        List<ZipEntry> entries = zip.entries();
        for (int i = 0; i < entries.size(); i++) {
            // do something
        }
    }
}

Then you can use different methods that are similar to the standard java ZipFile class. For example here are the publicly available methods.

• getEntry(String name) Returns the entry mapped with the specified name, or null if there is no entry mapped with that name.
• entries() Returns all the available entries as a list of ZipEntry.
• getInputStream(...) Opens(and returns) a bounded input stream currently positioning at the start of the requested entry's data block.
• size() Returns the total number of available entries.
• getComment() Returns the principal comment of the zip file.
• close() Closes the zip file, and any subsequent call to getInputStream(...) will throw an exception. However, other methods of the class that are saved in memory will still be available after call to close().

Please Note

• The ZipEntry we mentioned above is a part of this library and has similar methods as the standard ZipEntry class in java jdk.
• If you do not have a ZipEntry instance, and only have the name of the entry, you can use the minimal constructor ( i.e. ZipEntry(String name)) to obtain an input stream. Of course, you would get an exception if the entry does not exist.

Performance

The performance is similar to the Standard ZipFile class. Before this, the only way to read a zip file in this kind of situation was to use the ZipInputStream class which basically reads every byte in its way to get to the next entry. That is, to list, or to get data of all the entries of a zip file, it is equivalent of reading the whole file. Imagine you have to read some metadata within some big zip files, may be 100 zip files, think how much time it would take! Of course, you can use some caching technique, which I was doing for a long time, in fact there is still a library in the git repo, which does exactly that. But in any way, that is not enough, it takes a lot of memory, and the performance is limited to many constraints.

Please share & rate the library if you find it useful.

Happy coding!