title: zookeeper: Unsupported major.minor version 52.0
body: <p>I'm trying to follow the guide on the kafka website:
  <a href="https://kafka.apache.org/quickstart" rel="nofollow noreferrer">https://kafka.apache.org/quickstart</a>
  But when I use kafka_2.12-2.5.0 and try to start the zookeeper I get:</p>
  
  <pre><code>$ bin/zookeeper-server-start.sh  config/zookeeper.properties
      Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/zookeeper/server/quorum/QuorumPeerMain : 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)
  </code></pre>
  
  <p>I'm using redhat7.1.
  Tried to update java:</p>
  
  <pre><code>$ sudo yum install java-1.8.0-openjdk-devel
  Loaded plugins: langpacks, product-id, subscription-manager
  This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
  ...
  Package 1:java-1.8.0-openjdk-devel-1.8.0.31-2.b13.el7.x86_64 already installed and latest version
  Nothing to do
  </code></pre>
  
  <p>What version of Java should I have?</p>