Enterprise Java Development@TOPIC@
You will need a JDK 11 installed.
Although most of the source code and maven modules used in class are backwards compatible with JDK 8, the modules and the build system around it have been migrated to JDK 11. There are a few changes between JDK 8 and JDK 11 that will make flipping between the two difficult. Therefore target JDK 11 for use in class.
Removal of JavaEE APIs from JavaSE requiring additional dependencies for the JDK 11 classpath
Command line changes to the JDK that require custom maven-compiler-plugin configuration
Oracle JDK no longer free for commercial use. Suitable alternate is OpenJDK.
Keep the 32/64-bit choice consistent with what you download later for Eclipse.
Mac Users AdoptOpenJDK or thru package manager (e.g., brew)
Linux Users thru package manager (e.g., yum, apt)
$ sudo apt install openjdk-11-jdk
Windows Users Azul OpenJDK
Depending on how you performed the installation, you may need to add the JDK to your PATH
Figure 2.2. Mac Example
$ java -version openjdk version "11.0.4" 2019-07-16 OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.4+11) OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.4+11, mixed mode) $ javac -version javac 11.0.4
Figure 2.3. Ubuntu Linux Example
$ java -version openjdk version "11.0.4" 2019-07-16 OpenJDK Runtime Environment (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3) OpenJDK 64-Bit Server VM (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3, mixed mode, sharing) $ javac -version javac 11.0.4
Figure 2.4. Windows Example
> java -version openjdk version "11.0.4" 2019-07-16 LTS OpenJDK Runtime Environment Zulu11.33+15-CA (build 11.0.4+11-LTS) OpenJDK 64-Bit Server VM Zulu11.33+15-CA (build 11.0.4+11-LTS, mixed mode) >javac -version javac 11.0.4