Grip

SQL-like queries on JVM classes metadata using Kotlin DSL.

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Gradle:

repositories {
  mavenCentral()
}

dependencies {
  compile 'io.michaelrocks:grip:0.7.3-beta'
}

Usage

Before executing any queries you need to create an instance of Grip interface.

val grip = GripFactory.create(classpath)

Now you can query classes from a .jar file, or classes directory, or just a single .class file that satisfy some condition. For example that's how you can find all public classes in a .jar file.

val query = grip select classes from file where isPublic()

If you don't like the DSL syntax it's possible to use traditional method chaining.

val query = grip
    .select(classes)
    .from(file)
    .where(isPublic())

The query is a lazy object. It must be executed explicitly to return results. After the first execution results are cached.

val classes = query.execute()

The classes variable contains a map from Type to ClassMirror. ClassMirror is an object representation of class metadata. It provides functionality similar to java.lang.Class. There're other mirror classes such as MethodMirror, FieldMirror, AnnotationMirror and more.

Query conditions can be much more complicated than just isPublic(). You can combine multiple conditions with and, or, xor and not. That's how you can query all non-final classes that implement java.util.List.

val query = grip select classes from file where
    (not(isFinal()) and interfacesContain(getType<List<*>>()))

Moreover, you can query methods or fields that satisfy some conditions. Here's how you can find all deprecated methods from all classes.

val query = grip select methods from file where annotatedWith(getType<Deprecated>())

And finally, subqueries are supported. For example, you can queries public non-final fields from public classes.

val subquery = grip select classes from file where isPublic()
val query = grip select fields from subquery where (isPublic() and not(isFinal()))

There're more conditions available, which you can find here. But if you need a condition that's not present in the project you can add a new condition to your own project easily and use it in queries.

License

Copyright 2021 Michael Rozumyanskiy

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.