es 默认jdk地址

如果在启动es的时候，不配置JAVA_HOME,则es将使用：elasticsearch-7.1.1-node2\jdk

Eg:

配置了JAVA_HOME的启动信息：

[2019-07-13T18:50:34,526][INFO ][o.e.e.NodeEnvironment    ] [node-2] using [1] data paths, mounts [[鏂板姞鍗?(E:)]], net usable_space [44.5gb], net total_space [58.5gb], types [NTFS]

[2019-07-13T18:50:34,535][INFO ][o.e.e.NodeEnvironment    ] [node-2] heap size [990.7mb], compressed ordinary object pointers [true]
[2019-07-13T18:50:34,542][INFO ][o.e.n.Node               ] [node-2] node name [node-2], node ID [ZBW72mNvTbCO9IElFP1jeg], cluster name [my-application]
[2019-07-13T18:50:34,543][INFO ][o.e.n.Node               ] [node-2] version[7.1.1], pid[21564], build[default/zip/7a013de/2019-05-23T14:04:00.380842Z], OS[Windows 10/10.0/amd64], JVM[Oracle Corporation/Java HotSpot(TM) 64-Bit Server VM/1.8.0_161/25.161-b12]
[2019-07-13T18:50:34,544][INFO ][o.e.n.Node               ] [node-2] JVM home [D:\Program Files\Java\jdk1.8.0_161\jre]

没有配置JAVA_HOME的启动信息：

OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.
[2019-07-13T18:18:01,210][INFO ][o.e.e.NodeEnvironment    ] [node-2] using [1] data paths, mounts [[鏂板姞鍗?(E:)]], net usable_space [44.6gb], net total_space [58.5gb], types [NTFS]

[2019-07-13T18:18:01,357][INFO ][o.e.e.NodeEnvironment    ] [node-2] heap size [990.7mb], compressed ordinary object pointers [true]
[2019-07-13T18:18:01,473][INFO ][o.e.n.Node               ] [node-2] node name [node-2], node ID [ZBW72mNvTbCO9IElFP1jeg], cluster name [my-application]
[2019-07-13T18:18:01,477][INFO ][o.e.n.Node               ] [node-2] version[7.1.1], pid[17344], build[default/zip/7a013de/2019-05-23T14:04:00.380842Z], OS[Windows 10/10.0/amd64], JVM[Oracle Corporation/OpenJDK 64-Bit Server VM/12.0.1/12.0.1+12]
[2019-07-13T18:18:01,537][INFO ][o.e.n.Node               ] [node-2] JVM home [E:\es\es-cluster\elasticsearch-7.1.1-node2\jdk]