Zookeeper：不支持Major.Minor版本52.0

Question

我试图按照Kafka网站https://kafka.apache.org/quickstart上的指南操作，但当我使用kafka2.12-2.5.0并尝试启动zookeeper时，我得到了：

$ 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)

我用的是Redhat7.1。尝试更新Java：

$ 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

我应该有什么版本的Java？

Answer 1

这个'52.0'意味着它是用1.8jdk编译的，但您尝试主要用较低的jdk运行（或者甚至非常高的不兼容？）。默认情况下使用JAVA_HOME环境变量，所以希望您已经检查了基本内容：JAVA_HOME,java-version...甚至在运行指向正确的32/64 java之前强制导出java_home