Configuring gitpod with java (#523)

Author: kerwin612

.gitpod.Dockerfile

@@ -0,0 +1,7 @@
+FROM gitpod/workspace-full
+
+USER gitpod
+
+RUN bash -c ". /home/gitpod/.sdkman/bin/sdkman-init.sh && \
+    sdk install java 17.0.3-ms && \
+    sdk default java 17.0.3-ms"

.gitpod.yml

@@ -1,3 +1,6 @@
+image:
+    file: .gitpod.Dockerfile
+
 additionalRepositories:
     - url: https://github.com/apache/shenyu.git
       checkoutLocation: backend
@@ -19,8 +22,6 @@ tasks:
     - name: Setup backend
       before: cd ../backend
       init: |
-          sdk install java 17.0.11.fx-zulu < /dev/null
-          sdk default java 17.0.11.fx-zulu < /dev/null
           mvn clean install -DskipTests
       command: |
           gp sync-done setup-backend