Specify Java target using release flag

README.md

@@ -12,12 +12,15 @@ Like any Java project, include the jar into your classpath.
 
 The compilation, testing, launch, and delivery of the application are
 automated by means of a Gradle (https://gradle.org/) build file.
-In order to perform a build, all you need is
-a JDK -- version 111 and Gradle 6.8.x.
-Clone this GitHub repository `git clone https://github.com/ome/omero-renderer.git`.
+
+In order to perform a build, you need JDK 11 and Gradle 6.x installed. Clone
+this GitHub repository:
+
+    git clone https://github.com/ome/omero-renderer
+
 Go to the directory and enter:
 
-  gradle build
+    gradle build
 
 This will compile, build, test and create a distribution bundle.
 

build.gradle

@@ -1,6 +1,6 @@
 plugins {
     id "java-library"
-    id "org.openmicroscopy.project" version "5.7.0"
+    id "org.openmicroscopy.project" version "5.7.2"
 }
 
 group = "org.openmicroscopy"
@@ -11,9 +11,8 @@ repositories {
     mavenCentral()
 }
 
-java {
-    sourceCompatibility = JavaVersion.VERSION_1_8
-    targetCompatibility = JavaVersion.VERSION_1_8
+compileJava {
+    options.release = 8
 }
 
 dependencies {