debian/changelog

+ldapjdk (4.20.0+dfsg1-2) unstable; urgency=medium
+
+  * Build with JDK8.
+
+ -- Timo Aaltonen <tjaalton@debian.org>  Thu, 23 Aug 2018 01:36:45 +0300
+
 ldapjdk (4.20.0+dfsg1-1) unstable; urgency=medium
 
   * New upstream release.

debian/control

@@ -8,7 +8,7 @@ Build-Depends:
  debhelper (>= 10),
  javahelper,
 Build-Depends-Indep:
- default-jdk,
+ openjdk-8-jdk-headless,
  libjss-java (>= 4.5.0~),
  liboro-java,
 Standards-Version: 4.1.2

debian/rules

 #!/usr/bin/make -f
 
-export JAVA_HOME=/usr/lib/jvm/default-java
+export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-$(DEB_BUILD_ARCH)
 
 %:
 	dh $@ --with javahelper