Proguard is a free Java class file shrinker, optimizer, obfuscator, and preverifier that shrinks, optimises, and obfuscates Java class files. It finds and deletes any classes, fields, methods, or properties that are no longer in use. In Android, proguard is used by mobile app development businesses to optimise bytecode and delete unnecessary instructions. It uses short, meaningless names to rename the remaining classes, fields, and methods.
- Shrinking – identifies and deletes obsolete classes, fields, methods, and attributes
- Optimization – examines and optimises the methods’ bytecode.
- Obfuscation — uses short, meaningless names to rename the remaining classes, fields, and functions.
Shrinking is the process of shrinking APKs. Unused variables, methods, and classes can be detected with ProGuard. Unused code is eliminated from the application as well as the libraries. The process of shrinking is divided into two stages:
- Code shrinking is the process of removing unneeded variables, methods, classes, and properties from a programme and its library dependencies.
- Resource shrinking is the process of removing unnecessary resource files from a programme and its library dependencies.
The term “optimization” refers to the process of improving the bytecode. Instructions that aren’t used might have a detrimental impact on the app’s performance. Peephole optimization techniques reduce redundant instructions in a tiny part of the resulting code. At this point, any duplicate code is deleted, and any instructions that may be substituted with shorter ones are discovered and eliminated.
Obfuscation is the process of making a program’s code unreadable. The code will be incomprehensible to a third party that has acquired illegal access. The remaining classes, fields, and methods are renamed with random characters after the useless codes are removed. Hackers can’t see the original intent of code portions because of obfuscation.
What exactly is Proguard?
IAs a fragment TAG, you not use anything like MainFragment.class.getSimpleName(). While obfuscating, Proguard may give the same name (A.class) to two separate pieces in different packages. Two pieces will have the same TAG in this situation. It will result in a problem in your programme.
Keep your Proguard android mapping file in case you need to go back to the original coding. You may need to upload it to several locations, such as the PlayStore Console, in order to access the original stack-trace of the crashes.
ProGuard is a free Android java programme that allows us to achieve the following:
- Reduce (minimise) the code: Remove any code from the project that is no longer in use.
- Make the code more obfuscated: Rename the names of the classes, fields, and other objects.
- Improve the code: Inline the functions, for example.
ProGuard has the following influence on our project, in summary:
- It reduces the application’s size.
- It eliminates the unnecessary classes and methods that contribute to an Android application’s 64K method count limit.
- By obfuscating the code, it makes it difficult to reverse engineer the programme.
ProGuard is a free Java application for Android that serves three purposes:
Make the code as little as possible (remove unused code in the project)
Code shrinking (also known as tree-shaking) finds and securely eliminates unneeded classes, fields, methods, and attributes from your app and its library dependencies. For example, if your app only uses a few APIs from a library dependency, shrinking may identify and remove only that code from your app.
Resource shrinking eliminates unnecessary resources from your bundled software, including those in library dependencies. It works in tandem with code shrinking, allowing any resources that are no longer referenced to be securely deleted once useless code has been eliminated.
Make the code more obfuscated (rename the names of class, fields, etc.)
Short, meaningless names are used to rename the remaining classes, fields, and methods.
Improve the code.
Examines and rewrites your code to minimise the size of your DEX files even further. If Proguard detects that the else branch for a specific if/else statement is never used, it will delete the code for that branch.
Okay, but how does this help my app?
It eliminates all superfluous code and resources (including library dependencies) from your project, resulting in a substantial reduction in app size! You may think of Proguard as a vacuum sealer for your Android app, sucking away the extraneous bits and delivering a much smaller, more valuable package.
We are Appealing were able to reduce the size of our app by 40% simply by installing Proguard! It obfuscates the code, which means it renames classes, fields, and methods with semantically ambiguous names, making it difficult to reverse engineer the programme in addition to making the codebase smaller and more efficient.
What exactly do you mean when you say Proguard rules?
Proguard rules define the perimeters of Proguard, allowing you to specify which files/classes/libraries should be protected from being obfuscated, optimised, or downsized. Proguard rules may be added to the proguard-rules.pro file at the module’s root. Many popular libraries are automatically compatible with Proguard, but some require you to apply rules directly. These libraries offer the rules, as well as their documentation, and a simple Google search will bring them up for you.
Is there a way for me to see the list of objects that Proguard has removed?
You may create a report of code that has been eliminated (or preserved) as well as the mapping between obfuscated and original code on Android. The following are the files that can be used for that purpose:
- txt: This file describes the internal structure of all of the APK’s class files.
- txt: Translates the names of the original and obfuscated classes, methods, and fields.
- txt: This file contains a list of non-obfuscated classes and members.
- txt: This file contains a list of the code that was removed from the APK.
How do I activate ProGuard?
With basic setups, ProGuard is utilised to protect the application. It is open-source software that may be used in the release mode. To help you understand how ProGuard works, here are a few pointers:
- To activate and disable ProGuard for release builds, use the minifyEnabled parameter in the build.gradle file.
- ProGuard should not be enabled for Debug builds. With ProGuard for Debug builds, debugging will become incredibly difficult.
- The minifyEnabled parameter must be set to true to enable ProGuard.
- The minifyEnabled parameter is in charge of determining how release builds are configured.
- The getDefaultProGuardFile method in the Android SDK tools may be used to get the default ProGuard settings.
Most developers use ProGuard for its obfuscation capabilities, but the software’s advantages aren’t limited to security. ProGuard can significantly minimize the size of your app. It removes obsolete code and renames classes and their members with arbitrary characters.
When ProGuard is enabled, the application becomes smaller and more efficient. It also eliminates resources that are no longer referenced, in addition to unneeded codes. Additional dependencies are not required by ProGuard. It can simplify identifiers, combine classes and inline methods, and remove arguments that aren’t needed. ProGuard may remove logging code without affecting the original code.