Document removal of oraclejdk from install-jdk.sh (travis-ci#2906)

Co-authored-by: Michał Rybiński <[email protected]>

Author: muizzk

user/languages/java.md

@@ -31,7 +31,7 @@ new to Travis CI please read our [Tutorial](/user/tutorial/) and
 
 ## Overview
 
-The Travis CI environment contains various versions of OpenJDK, Oracle JDK,
+The Travis CI environment contains various versions of OpenJDK,
 Gradle, Maven and Ant.
 
 To use the Java environment, add the following to your `.travis.yml`:
@@ -176,19 +176,6 @@ addons:
 ```
 {: data-file=".travis.yml"}
 
-## Testing Against Multiple JDKs
-
-To test against multiple JDKs, use the `jdk:` key in `.travis.yml`. For example,
-to test against Oracle JDKs 8 and 9, as well as OpenJDK 8:
-
-```yaml
-jdk:
-  - oraclejdk8
-  - oraclejdk9
-  - openjdk8
-```
-{: data-file=".travis.yml"}
-
 > Note that testing against multiple Java versions is not supported on macOS. See
 the [macOS Build Environment](/user/reference/osx/#jdk-and-macos) for more
 details.
@@ -208,48 +195,19 @@ If your build needs to switch JDKs (Java 8 and below) during a job, you can do s
 
 ```yaml
 script:
-  - jdk_switcher use oraclejdk8
-  - # do stuff with Java 8
   - jdk_switcher use openjdk8
   - # do stuff with open Java 8
 ```
 {: data-file=".travis.yml"}
 
 Use of `jdk_switcher` also updates `$JAVA_HOME` appropriately.
 
-### Updating Oracle JDK 8 to a recent release
-
-Your repository may require a newer release of Oracle JDK than the pre-installed
-version.
-(You can consult [the list of published Oracle JDK packages](https://launchpad.net/~webupd8team/+archive/ubuntu/java).)
-
-The following example will use the latest Oracle JDK 8:
-
-```yaml
-addons:
-  apt:
-    packages:
-      - oracle-java8-installer
-```
-{: data-file=".travis.yml"}
-
 ## Using Java 10 and later
 
 > Take note that `oraclejdk10` is EOL since October 2018 and as such it's not supported anymore on Travis CI.
 > See [https://www.oracle.com/technetwork/java/javase/eol-135779.html](https://www.oracle.com/technetwork/java/javase/eol-135779.html){: data-proofer-ignore=""}.
-
-OracleJDK 11 and later are supported on Linux, and
-OpenJDK 10 and later are supported on Linux and macOS using
-[`install-jdk.sh`](https://github.com/sormuras/bach#install-jdksh).
-
-```yaml
-jdk:
-  - oraclejdk8
-  - oraclejdk11
-  - openjdk10
-  - openjdk11
-```
-{: data-file=".travis.yml"}
+>
+> `openjdk` is now the default jdk available on our VMs as `install-jdk` no longer installs `oraclejdk`. Please see this [Github Issue](https://github.com/sormuras/bach/issues/56) for context.
 
 ### Switching JDKs (to Java 10 and up) Within One Job