rollback to java 8, add comment in readme

.github/workflows/build_package.yml

@@ -8,10 +8,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 1.11
+      - name: Set up JDK 1.8
         uses: actions/setup-java@v1
         with:
-          java-version: 1.11
+          java-version: 1.8
       - name: Load local Maven repository cache
         uses: actions/cache@v2
         with:

.github/workflows/create-release.yml

@@ -12,10 +12,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 1.11
+      - name: Set up JDK 1.8
         uses: actions/setup-java@v1
         with:
-          java-version: 1.11
+          java-version: 1.8
           settings-path: ${{ github.workspace }}
 
       - name: Load local Maven repository cache

.github/workflows/java_checkstyle.yml

@@ -8,10 +8,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 1.11
+      - name: Set up JDK 1.8
         uses: actions/setup-java@v1
         with:
-          java-version: 1.11
+          java-version: 1.8
 
       - name: Download Checkstyle
         run: wget https://github.com/checkstyle/checkstyle/releases/download/checkstyle-8.31/checkstyle-8.31-all.jar

.github/workflows/nexus-publish-snapshots.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 1.11
+      - name: Set up JDK 1.8
         uses: actions/setup-java@v1
         with:
-          java-version: 1.11
+          java-version: 1.8
           settings-path: ${{ github.workspace }}
 
       - name: Load local Maven repository cache

.github/workflows/run_tests.yml

@@ -8,10 +8,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 1.11
+      - name: Set up JDK 1.8
         uses: actions/setup-java@v1
         with:
-          java-version: 1.11
+          java-version: 1.8
 
       - name: Load local Maven repository cache
         uses: actions/cache@v2

README.md

@@ -20,6 +20,8 @@ Compile the project with Maven and Java 8 and build an executable java archive:
 mvn clean package
 ```
 
+Java 8 MUST be used, as the package javax.xml.bin is deprecated/removed in future versions.
+
 The JAR file will be created in the ``/target`` folder
 
 ## How to use

pom.xml

@@ -7,15 +7,15 @@
 
     <groupId>life.qbic</groupId>
 	<artifactId>xml-manager-lib</artifactId>
-	<version>1.7.0-SNAPSHOT</version> <!-- <<QUBE_FORCE_BUMP>> -->
+	<version>1.7.0-SNAPSHOT</version>
 	<name>xml-manager-lib</name>
 	<url>http://github.com/qbicsoftware/xml-manager-lib</url>
 	<description>library for reading and writing of specific openBIS xml properties </description>
 	<packaging>jar</packaging>
 
     <properties>
-        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>11</maven.compiler.target>
+        <maven.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
 
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>