Summarizer should take input through stdin

[mahesh-hegde]

This is a summarizer command invocation on in_app_java sample after adding some gradle sources support.

(jnigen) INFO: execute java -jar .dart_tool/jnigen/ApiSummarizer.jar -s android\app\src\main\java;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\org.jetbrains.kotlin\kotlin-stdlib-jdk7\1.6.10\ccdfdab71f0f3ba104191d8f673d0620e7ed2e46\kotlin-stdlib-jdk7-1.6.10-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.loader\loader\1.0.0\b9ef587f3e46c7fe5b00264989764e43ff45cada\loader-1.0.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.lifecycle\lifecycle-livedata\2.0.0\740ce61935bd789380c01178bd8ce402402ebd2f\lifecycle-livedata-2.0.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\org.jetbrains\annotations\13.0\5991ca87ef1fb5544943d9abc5a9a37583fabe03\annotations-13.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.annotation\annotation\1.2.0\8945212022e5276658ab7864714ced3553ea724a\annotation-1.2.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\org.jetbrains.kotlinx\kotlinx-coroutines-core\1.5.2\eec85c0ad7175c570935d37cfe8a749c57991a53\kotlinx-coroutines-core-1.5.2-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\org.jetbrains.kotlinx\kotlinx-coroutines-android\1.5.2\363aa80c0a981d7bcb39bb904145de5b40b862f0\kotlinx-coroutines-android-1.5.2-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.activity\activity\1.0.0\28eb83e6a29ac3fbb87aa632cfa0e644a313f491\activity-1.0.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.window\window\1.0.0-beta04\c05d535f15eafda40ef406aaa4cb9df2d7f5377\window-1.0.0-beta04-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.lifecycle\lifecycle-livedata-core\2.0.0\c158207594782b42f3a2e08a5a029eb3319e4404\lifecycle-livedata-core-2.0.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.arch.core\core-runtime\2.1.0\f19886651c9946b39f83d8c184fd0e2ce9f43c16\core-runtime-2.1.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\io.flutter\flutter_embedding_release\1.0.0-ec975089acb540fc60752606a3d3ba809dd1528b\87eb8311c7c3d4b4716b30c2185b44b99608bbd1\flutter_embedding_release-1.0.0-ec975089acb540fc60752606a3d3ba809dd1528b-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.lifecycle\lifecycle-viewmodel\2.1.0\bfd86b9887c2343516f82bed91acbab34a45841d\lifecycle-viewmodel-2.1.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.savedstate\savedstate\1.0.0\e6daf87ed227a6f80bb8accb466755a5ee01a652\savedstate-1.0.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.tracing\tracing\1.0.0\aa6dafdce323d80a993c5427cf81d5072f023c8c\tracing-1.0.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.core\core\1.6.0\7e14a47159a1cd7e5744d0fe465fbc97843d984a\core-1.6.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\org.jetbrains.kotlin\kotlin-stdlib-common\1.6.10\884efb386c94b1ee8e2ca37335264a0ffb155250\kotlin-stdlib-common-1.6.10-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\org.jetbrains.kotlin\kotlin-stdlib-jdk8\1.5.30\171265ccd1f7a4307c3cb8eedd9115e662013190\kotlin-stdlib-jdk8-1.5.30-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.emoji2\emoji2\1.3.0\788179fcab96cd6ec9a3e284e2a509545dc0fb8d\emoji2-1.3.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\org.jetbrains.kotlin\kotlin-stdlib\1.6.10\a6284476c56bd752eb0020e062c78c930abdc168\kotlin-stdlib-1.6.10-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.arch.core\core-common\2.1.0\80ac2d7c8e6400ce2fbc663cd1a7e1cbef38c4b8\core-common-2.1.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.versionedparcelable\versionedparcelable\1.1.1\d9085927216387af679d18b6f472bc0fc5c7cc81\versionedparcelable-1.1.1-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.startup\startup-runtime\1.1.1\714974d4ab4858eab9395d3b048002108b62cf0a\startup-runtime-1.1.1-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.lifecycle\lifecycle-runtime\2.4.1\ae7040cf314de81d20ac69f28f5ab6c9a2c0d1ab\lifecycle-runtime-2.4.1-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.customview\customview\1.0.0\61f6a717d144dff3a6bda413d9abeeb2bca71581\customview-1.0.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.lifecycle\lifecycle-common\2.4.1\29609e3d01eaafd06c688c5366154174cf686c12\lifecycle-common-2.4.1-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.annotation\annotation-experimental\1.1.0\238eb640abf1ca6c952c7cd2e9423fe7f715713f\annotation-experimental-1.1.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.collection\collection\1.1.0\bae67b0019fbb38498198fcc2d0282a340b71c5b\collection-1.1.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.window\window-java\1.0.0-beta04\aebe0d5dd92117437900757652f05fd10dc45382\window-java-1.0.0-beta04-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.fragment\fragment\1.1.0\b9ebb04df2cb0cad4419af3c658690bc82aa5706\fragment-1.1.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.viewpager\viewpager\1.0.0\db045f92188b9d247d5f556866f8861ab68528f0\viewpager-1.0.0-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.lifecycle\lifecycle-common-java8\2.4.1\5b8f86fea035328fc9e8c660773037a3401ce25f\lifecycle-common-java8-2.4.1-sources.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\org.jetbrains.kotlinx\kotlinx-coroutines-core-jvm\1.5.2\d4724dfd0c4e340e15bd681a47e786bac9fd77a3\kotlinx-coroutines-core-jvm-1.5.2-sources.jar -c C:\Users\Concurrent\AppData\Local\Android\Sdk\platforms\android-33\android.jar;C:\Users\Concurrent\Code\Flutter\jnigen\jnigen\example\in_app_java\build\app\intermediates\compile_and_runtime_not_namespaced_r_class_jar\release\R.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\010799bb733d735e6bc7eb55a004ce51\transformed\jetified-libs.jar;C:\Users\Concurrent\Code\Flutter\jnigen\jnigen\example\in_app_java\build\jni\intermediates\compile_library_classes_jar\release\classes.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\f5329812119b63e8d80e90f8e279fb64\transformed\jetified-flutter_embedding_release-1.0.0-ec975089acb540fc60752606a3d3ba809dd1528b.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\4b6714e8764d36fc5f2963ce7e32668c\transformed\jetified-window-java-1.0.0-beta04-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\2ed1856e8509c3559e509d57d5163600\transformed\jetified-window-1.0.0-beta04-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\598adb5e9149720d13f0bd0a0dcb6ee8\transformed\jetified-kotlinx-coroutines-android-1.5.2.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\efb248efc67e5b15184e44f46099cae3\transformed\jetified-kotlinx-coroutines-core-jvm-1.5.2.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\bf1c1216bd6ae07994ad3865cc233715\transformed\jetified-kotlin-stdlib-jdk8-1.5.30.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\c1ad1417f1a0d960d63d2b4e99f2c3ab\transformed\jetified-kotlin-stdlib-jdk7-1.6.10.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\8c0c5e352fdc1a448b53f679be4ca527\transformed\jetified-emoji2-1.3.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\e419da159160990b7feff3b389d2b5a8\transformed\jetified-armeabi_v7a_release-1.0.0-ec975089acb540fc60752606a3d3ba809dd1528b.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\70e7a4805f13d7f3aa7cfd7c635bc7d7\transformed\jetified-arm64_v8a_release-1.0.0-ec975089acb540fc60752606a3d3ba809dd1528b.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\0eaf6f4c95e9479426bbbd2f560f3453\transformed\jetified-x86_64_release-1.0.0-ec975089acb540fc60752606a3d3ba809dd1528b.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.lifecycle\lifecycle-common-java8\2.4.1\5b8f86fea035328fc9e8c660773037a3401ce25f\lifecycle-common-java8-2.4.1.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\cdf88c5cc537aaddfc2c2050fa347e9c\transformed\fragment-1.1.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\ea9559528b708c2ddbd8ffc8f6a391bc\transformed\viewpager-1.0.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\44759425f3db5f137147e512ecde1a3c\transformed\loader-1.0.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\b446ae01cc4feea870f9d4cdd76bbbed\transformed\jetified-activity-1.0.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\58d181116539456738cbc5eec385f703\transformed\customview-1.0.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\a5d1d8f25f8005438aa6f0c30d5c502a\transformed\core-1.6.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\2af0f27b0b84a53922472a0e6210c91a\transformed\lifecycle-runtime-2.4.1-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\1f9c0389144dc98c98c15c79358ad23f\transformed\jetified-savedstate-1.0.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\65c8ce426ffc7583bdb81c3188d22ba8\transformed\lifecycle-livedata-2.0.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\61fa0487a7e406de4f3e264e210faff8\transformed\lifecycle-livedata-core-2.0.0-api.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.lifecycle\lifecycle-common\2.4.1\1fdb7349701e9cf2f0a69fc10642b6fef6bb3e12\lifecycle-common-2.4.1.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\d8a303489ba2ae0a75ce057af4ce0e35\transformed\versionedparcelable-1.1.1-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\08d13d8d279ac4ef123bdae018db4637\transformed\core-runtime-2.1.0-api.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.arch.core\core-common\2.1.0\b3152fc64428c9354344bd89848ecddc09b6f07e\core-common-2.1.0.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.collection\collection\1.1.0\1f27220b47669781457de0d600849a5de0e89909\collection-1.1.0.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\ddf2acae941e89634e9d6193d68f4a65\transformed\lifecycle-viewmodel-2.1.0-api.jar;C:\Users\Concurrent\.gradle\caches\modules-2\files-2.1\androidx.annotation\annotation\1.2.0\57136ff68ee784c6e19db34ed4a175338fadfde1\annotation-1.2.0.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\16b2a3659d3f66cfb4dac6a52d79820d\transformed\jetified-annotation-experimental-1.1.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\58cbff39727146a52203300842706cfd\transformed\jetified-tracing-1.0.0-api.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\c0314e47cfdb88c484579924d748772c\transformed\jetified-kotlin-stdlib-1.6.10.jar;C:\Users\Concurrent\.gradle\caches\transforms-3\d742cecfb9af51effcb2f82c5fa547fe\transformed\jetified-annotations-13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com.example.in_app_java.AndroidUtils androidx.emoji2.text.EmojiCompat androidx.emoji2.text.DefaultEmojiCompatConfig android.os.Build java.util.HashMap

With an app which has more dependencies, we might cross OS-imposed limits of command length and it's not great for debugging either.

We should take this class paths etc information as structured JSON in summarizer, reading from System.in.

[mahesh-hegde]

Since this is marked good first issue, here are the steps to solve this

Steps

• In the summarizer java project, (jnigen/java), look out for SummarizerOptions class.

• This class is being parsed from command line using Apache commons CLI, add factory (static) methods to obtain an instance of this class by parsing JSON, and another instance method to dump it back to JSON (for debugging purposes).

  • We may want to retain the command line invocation, for debugging purposes, because writing JSON into summarizer stdin is hard when debugging. So you may instead add another option --read-config-from-stdin in current fromCommandLine factory constructor, which then constructs a SummarizerOptions from stdin. Iterate and decide which is optimal design here.

• print SummarizerOptions to stderr, because jnigen will print it when invocation fails. You may want to pretty-print this.

• in summary class, add a SummarizerOptions class which is exact copy of this. Use json-serializable to serialize. (We are already using it for element types, so no need to add dependency).

• in getSummary make required adjustments.

Decisions

• Should this JSON be printed to log? If so, it must be on one line.

• Remove current command invocation of summarizer vs. keep it and use another argument (or lack of argument?) to read from stdin.

[Karan741187]

Sir I wish to contribute on this one

[Karan741187]

Can you elaborate this point
"This class is being parsed from command line using Apache commons CLI, add factory (static) methods to obtain an instance of this class by parsing JSON, and another instance method to dump it back to JSON (for debugging purposes)"

[Karan741187]

Do we have to parse "exampleClassSummary.json" return a object. And what is "dump it back to JSON", is it encoding new json file?

[mahesh-hegde]

Can you elaborate this point

"This class is being parsed from command line using Apache commons CLI, add factory (static) methods to obtain an instance of this class by parsing JSON, and another instance method to dump it back to JSON (for debugging purposes)"

We have a Java part and a Dart part in this codebase. Java part (It's a maven project in jnigen/java folder) parses the Java code we give to jnigen, and gives us a summary in JSON format. This part is called the summarizer.

For this, we need to pass the various options. Like class-path (where to find required java JARs), source-path (where to find java files to parse) etc..

All of that is stored in SummarizerOptions class.

So what we are doing now is, we invoke this summarizer as separate command, java -jar ApiSummarizer.jar etc.. You can see this command in the logs of executing jnigen.

What this issue is about: the command gets very long and cluttered if we pass everything as command option. So we want to read that from standard input System.in.

For that, we need some structure. You might have done scanner.next() etc.. when you're learning java. But here the input is complicated. So we have to read those options in JSON format.

If we read JSON, we can read all values it into SummarizerOptions class directly, using Jackson-databind library. We already using that library.

The task is to modify the APISummarizer java code, and the dart code which calls it, so that instead of command options, we pass options in JSON format through System.in (stdin of process on dart side).

Do we have to parse "exampleClassSummary.json" return a object. And what is "dump it back to JSON", is it encoding new json file?

You're probably looking at test file. If you're not familiar with pipes, json, serialization etc.. this might be hard (I know these aren't taught at universities properly). feel free to ask any question you get.

[Karan741187]

I had some doubts
1.Are we passing the options through the terminal or they are getting read from any dart file.Because you mentioned stdin of process on dart side

2.Which dart code is calling the Java code.
I went through the setup.dart and jni.dart
but couldn't find anything of Java.

I ran Main.java and saw all the commons.cli implementation with SummerizerOptions.java.

[Karan741187]

The term Standard input is being used very often.So far i know it means taking input from user through keyboard right?

[mahesh-hegde]

Sure. That's a good start.

Are we passing the options through the terminal
Standard input is being used very often

In any OS, Standard input is an abstraction your program sees, input doesn't necessarily come from the terminal.

If you do echo "HI" | cat in Linux Bash, there are 2 processes, (echo & cat), the output of first one will be passed to input of second. Like that, we can programmatically give input to any command.

And the inverse, we can programmatically invoke and read output of the command.

How is this possible? conceptually, input & output are just streams just like any other file. If you create a process from your program (eg run a command), you can write to its input and read from its output. So we don't have to do that manually from terminal.

Which dart code is calling the Java code.

It's jnigen that calls the JAR command.

https://github.com/dart-lang/jnigen/blob/f7e6de15735f21678f899bf9f5c98fdbdaea793b/jnigen/lib/src/summary/summary.dart#L89

[Karan741187]

Sir today I was trying to make a process object with start function and wanted to give stdin but i got file not found exception
Although the file was in current working directory

• It ran fine if i didn't give stdin.
  I could invoke a Java programe through run and start both by giving java in exec and test.java in args but

when gave cat as exec and A file path through stdin it gave the error file not found

[mahesh-hegde]

I don't quite understand what you're trying to do. Can you paste the code?

[Karan741187]

`import 'dart:io';
import 'dart:convert';

Future main() async
{ Process.start('cat', []).then((Process ps) {
ps.stdout.transform(utf8.decoder).listen((event) {
print('$event');
});
ps.stdin.write('C:\Users\Dell\IdeaProjects\Processpractice\myfile.txt');

Process.killPid(ps.pid);
});
}`

[Karan741187]

when i cat command in powershell it asks for path[0] then i enter the path and it keeps on asking till i press enter two times i was trying to pass the file path through stdin but throws this exception

`Unhandled exception:
ProcessException: The system cannot find the file specified.

Command: cat
#0 _ProcessImpl._start (dart:io-patch/process_patch.dart:401:33)
dart-archive/jnigen#1 Process.start (dart:io-patch/process_patch.dart:38:20)
dart-archive/jnigen#2 main (file:///C:/Users/Dell/IdeaProjects/Processpractice/progprac.dart:5:11)
#802 _delayEntrypointInvocation. (dart:isolate-patch/isolate_patch.dart:297:19)
dart-archive/jnigen#4 _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:192:26)

Process finished with exit code 255
`