OpenJDK9 directory structures

Take a look at some of the tree structures of the various folders within the OpenJDK9 directory structure.

build folder

$ tree -fL 2 build

build
└── build/linux-x86_64-normal-server-release
    ├── build/linux-x86_64-normal-server-release/bootcycle-spec.gmk
    ├── build/linux-x86_64-normal-server-release/build.log
    ├── build/linux-x86_64-normal-server-release/build.log.old
    ├── build/linux-x86_64-normal-server-release/buildtools
    ├── build/linux-x86_64-normal-server-release/compare.sh
    ├── build/linux-x86_64-normal-server-release/config.h
    ├── build/linux-x86_64-normal-server-release/config.log
    ├── build/linux-x86_64-normal-server-release/config.status
    ├── build/linux-x86_64-normal-server-release/hotspot
    ├── build/linux-x86_64-normal-server-release/hotspot-spec.gmk
    ├── build/linux-x86_64-normal-server-release/images
    ├── build/linux-x86_64-normal-server-release/jdk
    ├── build/linux-x86_64-normal-server-release/Makefile
    ├── build/linux-x86_64-normal-server-release/make-support
    ├── build/linux-x86_64-normal-server-release/nashorn
    ├── build/linux-x86_64-normal-server-release/source_tips
    ├── build/linux-x86_64-normal-server-release/spec.gmk
    ├── build/linux-x86_64-normal-server-release/spec.sh
    └── build/linux-x86_64-normal-server-release/support

build/[OS-related-name]/images folder
*[OS-related-name] - could be linux.... or macosx....

$ tree -fL 2 images

images
├── images/demo
│   ├── images/demo/applets
│   ├── images/demo/jfc
│   ├── images/demo/jvmti
│   ├── images/demo/management
│   ├── images/demo/nbproject
│   ├── images/demo/README
│   └── images/demo/scripting
├── images/jdk
│   ├── images/jdk/ASSEMBLY_EXCEPTION
│   ├── images/jdk/bin
│   ├── images/jdk/conf
│   ├── images/jdk/demo
│   ├── images/jdk/include
│   ├── images/jdk/jrt-fs.jar
│   ├── images/jdk/lib
│   ├── images/jdk/LICENSE
│   ├── images/jdk/man
│   ├── images/jdk/release
│   ├── images/jdk/sample
│   ├── images/jdk/src.zip
│   └── images/jdk/THIRD_PARTY_README
├── images/_jdk-jimages-create.marker
├── images/jdk-sorted-modules
├── images/jre
│   ├── images/jre/ASSEMBLY_EXCEPTION
│   ├── images/jre/bin
│   ├── images/jre/conf
│   ├── images/jre/lib
│   ├── images/jre/LICENSE
│   ├── images/jre/man
│   ├── images/jre/release
│   └── images/jre/THIRD_PARTY_README
├── images/_jre-jimages-create.marker
├── images/jre-sorted-modules
├── images/sample
│   ├── images/sample/annotations
│   ├── images/sample/forkjoin
│   ├── images/sample/jmx
│   ├── images/sample/lambda
│   ├── images/sample/nbproject
│   ├── images/sample/nio
│   ├── images/sample/README
│   ├── images/sample/scripting
│   └── images/sample/try-with-resources
└── images/sec-bin.zip

jdk/src folder

$ cd sources/jdk9/jdk/src

or

$ cd dev/jdk9_dev/jdk/src

$ tree -dflL 5 java.base/share/classes/java/util

java.base/share/classes/java/util
├── java.base/share/classes/java/util/concurrent
│   ├── java.base/share/classes/java/util/concurrent/atomic
│   └── java.base/share/classes/java/util/concurrent/locks
├── java.base/share/classes/java/util/function
├── java.base/share/classes/java/util/jar
├── java.base/share/classes/java/util/regex
├── java.base/share/classes/java/util/spi
├── java.base/share/classes/java/util/stream
└── java.base/share/classes/java/util/zip

java.base folder

$ tree -fldL 5 java.base  | less

$ tree -dflL 5 java.base/share/classes/java  

$ tree -dflL 5 java.base/share/classes/java

java.io package

$  tree -flL 5 java.base/share/classes/java/io
$  tree -dflL 5 java.base/share/classes/java/io
│   ├── java.base/share/classes/java/io

java.lang package

$  tree -dflL 5 java.base/share/classes/java/lang
│   ├── java.base/share/classes/java/lang
.
.
.

java.nio package

$  tree -dflL 5 java.base/share/classes/java/nio
│   ├── java.base/share/classes/java/nio

java.text package

$  tree -dflL 5 java.base/share/classes/java/text
│   ├── java.base/share/classes/java/text
.

java.time package

$  tree -dflL 5 java.base/share/classes/java/time
│   ├── java.base/share/classes/java/time
.
.
.

java.util package

$ tree -dflL 5 java.base/share/classes/java/util
│   └── java.base/share/classes/java/util

(sources/jdk9/jdk/src) or (dev/jdk9_dev/jdk/src) folder

$ tree -dflL 5 java.base/share/classes/java/util

java.base/share/classes/java/util
├── java.base/share/classes/java/util/concurrent
│   ├── java.base/share/classes/java/util/concurrent/atomic
│   └── java.base/share/classes/java/util/concurrent/locks
├── java.base/share/classes/java/util/function
├── java.base/share/classes/java/util/jar
├── java.base/share/classes/java/util/regex
├── java.base/share/classes/java/util/spi
├── java.base/share/classes/java/util/stream
└── java.base/share/classes/java/util/zip

(sources/jdk9/jdk/src) or (dev/jdk9_dev/jdk/src) folder

$ tree -fl | grep "/Socket."

OpenJDK 9 - jdk9 (sources/jdk9/jdk/src) or (dev/jdk9_dev/jdk/src)

$ ls java.sql/share/classes/java/sql