Edge UI upgrade to 4.17.01 failing with Unsupported major.minor version 52.0 exception

[adevegowda]

When we are trying to upgrade the Edge UI component from 4.16.09 to 4.17.01, we are getting the following exception:

root@gtwtplapapiv01:~ # /opt/apigee/apigee-setup/bin/update.sh -c ui -f /tmp/ProdConfigFile
Using defaults from /tmp/ProdConfigFile
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Service upgrade: edge-ui
...
apigee-configutil: edge-ui: # OK
Exception in thread "main" java.lang.UnsupportedClassVersionError: utils/EncryptUtil : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:800) 
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

I have checked the Java version on the system is Java 8 for which the major.minor is 52.0

root@edgeui01:~ # java -version 
openjdk version "1.8.0_111" 
OpenJDK Runtime Environment (build 1.8.0_111-b15) 
OpenJDK 64-Bit Server VM (build 25.111-b15, mixed mode)

Why am I still getting the exception Unsupported major.minor version 52.0 ?

[adevegowda · Accepted solution]

1. The exception "Unsupported major.minor version 52.0" clearly indicates that there is a mismatch of the Java version that is used during upgrade vs the Java version in Edge component binaries.
2. The "major.minor version 52.0" indicates that we need a Java 8 while running the upgrade scripts. However, we seem to be referring to Java 7 installation directory somewhere in the Edge UI upgrade scripts, so we are hitting this problem.
3. Searched and found that the JAVA_HOME variable was pointing to Java 7 installation directory in <code>/opt/apigee/etc/defaults.sh</code>
4. Modified the JAVA_HOME variable to point to Java 8 installation directory.

Post this change, the upgrade completed successfully.