archlinux-java: add page (#4889)

pages/linux/archlinux-java.md

@@ -0,0 +1,20 @@
+# archlinux-java
+
+> A helper script that provides functionalities for Java environments.
+> More information: <https://github.com/michaellass/archlinux-java-run>.
+
+- List installed Java environments:
+
+`archlinux-java status`
+
+- Set the default Java environment:
+
+`archlinux-java set {{java_environment}}`
+
+- Unset the default Java environment:
+
+`archlinux-java unset`
+
+- Set the default Java environment automatically:
+
+`archlinux-java fix`