# How to call Kotlin compiler to compile some Kotlin source files from Java?

**URL:** <https://discuss.kotlinlang.org/t/how-to-call-kotlin-compiler-to-compile-some-kotlin-source-files-from-java/872>\
**Category:** Uncategorized\
**Created:** [April 1, 2013, 3:41am UTC](https://discuss.kotlinlang.org/t/how-to-call-kotlin-compiler-to-compile-some-kotlin-source-files-from-java/872 "2013-04-01T03:41:15Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![freewind](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/freewind/32/1479_2.png) [@freewind](https://discuss.kotlinlang.org/u/freewind)\
**Post date:** [April 1, 2013, 3:41am UTC](https://discuss.kotlinlang.org/t/how-to-call-kotlin-compiler-to-compile-some-kotlin-source-files-from-java/872/1 "2013-04-01T03:41:15Z")

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I want to call Kotlin compiler to comiple some Kotlin source files from Java, how to do it?

I mean to invoke some classes and functions, not calling command line from Java.

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**Author:** ![abreslav](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/abreslav/32/8279_2.png) [@abreslav](https://discuss.kotlinlang.org/u/abreslav)\
**Post date:** [April 1, 2013, 9:14am UTC](https://discuss.kotlinlang.org/t/how-to-call-kotlin-compiler-to-compile-some-kotlin-source-files-from-java/872/2 "2013-04-01T09:14:13Z")

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Have a look at the sources of build tools that run Kotlin:

For example, here’s what Maven does: [https://github.com/JetBrains/kotlin/blob/master/libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/KotlinCompileMojoBase.java](https://github.com/JetBrains/kotlin/blob/master/libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/KotlinCompileMojoBase.java)

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**Author:** ![freewind](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/freewind/32/1479_2.png) [@freewind](https://discuss.kotlinlang.org/u/freewind)\
**Post date:** [April 1, 2013, 10:20am UTC](https://discuss.kotlinlang.org/t/how-to-call-kotlin-compiler-to-compile-some-kotlin-source-files-from-java/872/3 "2013-04-01T10:20:42Z")

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It seems Kotlin compiler can only accept source dirs and output the generated bytecode to some dirs. Is it possible to pass some kotlin files and get the generate bytecode directly?

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**Author:** ![abreslav](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/abreslav/32/8279_2.png) [@abreslav](https://discuss.kotlinlang.org/u/abreslav)\
**Post date:** [April 1, 2013, 10:42am UTC](https://discuss.kotlinlang.org/t/how-to-call-kotlin-compiler-to-compile-some-kotlin-source-files-from-java/872/4 "2013-04-01T10:42:46Z")

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Yes, you can add individual source files instead of dirs. This does not apply to outputs, because we generate more class files than there're input source files (you can declare many classes in a source file).

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**Author:** ![freewind](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/freewind/32/1479_2.png) [@freewind](https://discuss.kotlinlang.org/u/freewind)\
**Post date:** [April 1, 2013, 10:44am UTC](https://discuss.kotlinlang.org/t/how-to-call-kotlin-compiler-to-compile-some-kotlin-source-files-from-java/872/5 "2013-04-01T10:44:14Z")

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Can we get generated bytecode back directly, instead of .class files?

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**Author:** ![abreslav](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/abreslav/32/8279_2.png) [@abreslav](https://discuss.kotlinlang.org/u/abreslav)\
**Post date:** [April 1, 2013, 10:48am UTC](https://discuss.kotlinlang.org/t/how-to-call-kotlin-compiler-to-compile-some-kotlin-source-files-from-java/872/6 "2013-04-01T10:48:55Z")

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Yes, have a look at how class files are written

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**Author:** ![freewind](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/freewind/32/1479_2.png) [@freewind](https://discuss.kotlinlang.org/u/freewind)\
**Post date:** [April 1, 2013, 10:50am UTC](https://discuss.kotlinlang.org/t/how-to-call-kotlin-compiler-to-compile-some-kotlin-source-files-from-java/872/7 "2013-04-01T10:50:00Z")

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Thank you!