https://github.com/guardsquare/kotlin-metadata-printer

Prints the Kotlin metadata attached to Java class files
https://github.com/guardsquare/kotlin-metadata-printer

java kotlin kotlin-metadata pretty-printer proguard proguard-core

Last synced: about 7 hours ago
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Prints the Kotlin metadata attached to Java class files

• Host: GitHub
• URL: https://github.com/guardsquare/kotlin-metadata-printer
• Owner: Guardsquare
• License: apache-2.0
• Created: 2020-05-25T13:48:26.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2024-04-30T08:26:21.000Z (6 months ago)
• Last Synced: 2024-04-30T09:35:46.850Z (6 months ago)
• Topics: java, kotlin, kotlin-metadata, pretty-printer, proguard, proguard-core
• Language: Java
• Homepage: https://tools.guardsquare.com/kotlin-metadata-printer/
• Size: 3.3 MB
• Stars: 53
• Watchers: 16
• Forks: 6
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

Awesome Lists containing this project

README

        
Kotlin Metadata Printer




  

  

  

  

  

  

  

  

    

  

  

  

    

  



The Kotlin metadata printer is a free tool to print the Kotlin metadata in

a human-readable format. The printer is built on the

[ProGuardCORE](https://github.com/Guardsquare/proguard-core) library and can

process class files, zip files, jars or apks.

The Kotlin metadata printer is integrated in [ProGuard Playground](https://playground.proguard.com/) or you can run it [locally](#executing).



  



## Building

You can build the Kotlin metadata printer jar by executing the following Gradle command:

    ./gradlew build

Once built a jar will be created in lib/kotlin-metadata-printer.jar

## Executing

You can execute the printer directly through gradle as follows:

    ./gradlew :kmp-cli:run --args "input.{apk,jar,zip,class}"

Or you can execute the built printer jar as follows:

    java -jar lib/kotlin-metadata-printer.jar input.{apk,jar,zip,class}

## Options

    --filter '' class name filter e.g. --filter '!android.**,com.mypackage.**'

    --output ''      write output to this file instead of stdout e.g. --output 'myfile.txt'

    --json                       output the metadata in a JSON structure

    --divider                    a string that is printed between each Kotlin metadata

## Example

The following example is a basic Android activity class written in Kotlin:

```kotlin

/**

 * Sample activity that displays "Hello world!".

 */

class HelloWorldActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_main)

    }

}

```

and this is its associated metadata as printed by the Kotlin metadata printer:

```

/**

* Kotlin class.

* From Java class: com.example.HelloWorldActivity

*/

class HelloWorldActivity : android.support.v7.app.AppCompatActivity {

    // Functions

    protected open fun onCreate(savedInstanceState: android.os.Bundle?) { }

}

```

## Using as a library

The project is split into CLI (`kmp-cli`) and library (`kmp-lib`) modules. To use the 

printer programmatically from your project add a dependency on the library and then use 

the `KotlinMetadataPrinter` class along with a ProGuardCORE `ClassPool`. The printed 

metadata is placed into the processing info field of the `Clazz`.

```java

import com.guardsquare.proguard.kotlin.printer.KotlinMetadataPrinter;

import proguard.classfile.kotlin.visitor.ReferencedKotlinMetadataVisitor;

import proguard.classfile.visitor.MultiClassVisitor;

import proguard.classfile.util.kotlin.KotlinMetadataInitializer;

import proguard.classfile.ClassPool;

import static proguard.io.util.IOUtil.read;

public class Main

{

    public static void main(String[] args)

    {

        ClassPool programClassPool = read(args[0], false);

        programClassPool.classesAccept(

            new MultiClassVisitor(    

            new KotlinMetadataInitializer((clazz, errorMessage) -> System.err.println(errorMessage)),        

            new ReferencedKotlinMetadataVisitor(

            new KotlinMetadataPrinter(programClassPool)))

        );

        programClassPool.classesAccept(clazz -> System.out.println(clazz.getProcessingInfo()));

    }

}

```

## Contributing

The **Kotlin metadata printer** is built on the

[ProGuardCORE](https://github.com/Guardsquare/proguard-core) library.

Contributions, issues and feature requests are welcome in both projects.

Feel free to check the [issues](issues) page and the [contributing

guide](CONTRIBUTING.md) if you would like to contribute.

## License

The **Kotlin metadata printer** is distributed under the terms of

the [Apache License Version 2.0](LICENSE).

Enjoy!

Copyright (c) 2002-2023 Guardsquare NV