【Exception】Cannot find Java 1.8 or higher.

打开visualvm时，出现如下报错：

本机明明安装了OpenJDK8，为什么它提示Connot find Java 1.8 or higher？
肯定是 visualvm 的配置没有指向本机正确的JAVA_HOME。

调整visualvm_213/etc/visualvm.conf文件中的配置，使其指向本机正确的JAVA_HOME：

# Default location of JDK:
#
# It can be overridden on command line by using --jdkhome 
# Be careful when changing jdkhome.
# There are two VisualVM launchers for Windows (32-bit and 64-bit) and
# installer points to one of those in the VisualVM application shortcut 
# based on the Java version selected at installation time.
#
#visualvm_jdkhome="/path/to/jdk"
visualvm_jdkhome="C:/app/openjdk8"