问题
I have this strange situation with Tomcat8.exe in Windows 10.
My JAVA_HOME environment variable defined in Windows System environment points at JDK 1.8 path:
JAVA_HOME=C:\Program Files\Java\jdk1.8.0_65
When I run "C:\Program Files\Apache Software Foundation\Tomcat 8.0\bin\Tomcat8.exe", the server starts with another JDK, as I can see in catalina.log:
12-May-2016 08:57:28.250 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server version: Apache Tomcat/8.0.30
12-May-2016 08:57:28.253 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server built: Dec 1 2015 22:30:46 UTC
12-May-2016 08:57:28.254 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Server number: 8.0.30.0
12-May-2016 08:57:28.254 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Name: Windows 8
12-May-2016 08:57:28.255 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log OS Version: 6.2
12-May-2016 08:57:28.255 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Architecture: amd64
12-May-2016 08:57:28.255 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Java Home: C:\Program Files\Java\jdk1.7.0_79\jre
12-May-2016 08:57:28.256 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Version: 1.7.0_79-b15
12-May-2016 08:57:28.256 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Vendor: Oracle Corporation
12-May-2016 08:57:28.256 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_BASE: C:\Program Files\Apache Software Foundation\Tomcat 8.0
12-May-2016 08:57:28.257 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_HOME: C:\Program Files\Apache Software Foundation\Tomcat 8.0
12-May-2016 08:57:28.257 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.home=C:\Program Files\Apache Software Foundation\Tomcat 8.0
12-May-2016 08:57:28.258 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.base=C:\Program Files\Apache Software Foundation\Tomcat 8.0
12-May-2016 08:57:28.259 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.endorsed.dirs=C:\Program Files\Apache Software Foundation\Tomcat 8.0\endorsed
12-May-2016 08:57:28.261 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.io.tmpdir=C:\Program Files\Apache Software Foundation\Tomcat 8.0\temp
12-May-2016 08:57:28.261 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
12-May-2016 08:57:28.262 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.config.file=C:\Program Files\Apache Software Foundation\Tomcat 8.0\conf\logging.properties
12-May-2016 08:57:28.264 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: exit
12-May-2016 08:57:28.265 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Xms128m
12-May-2016 08:57:28.266 INFO [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Xmx256m
12-May-2016 08:57:28.267 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Apache Software Foundation\Tomcat 8.0\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\ProgramData\Oracle\Java\javapath;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\Program Files\Java\jdk1.8.0_65\bin;.
I don't understand the source of "Java Home: C:\Program Files\Java\jdk1.7.0_79\jre".
I tried a find in files search of "1.7" in all Tomcat files and subfolders, the only occourence appears in the logs...
The destination of the link is "C:\Program Files\Apache Software Foundation\Tomcat 8.0\bin\Tomcat8.exe", there are no others variables.
Furthermore, the JDK 1.7 is not in the system Path!
How can I force the JDK 1.8?
Thanks in advance.
EDIT
This is the print of set command in prompt:
C:\Program Files\Apache Software Foundation\Tomcat 8.0\bin>set
ALLUSERSPROFILE=C:\ProgramData
APPDATA=C:\Users\Alessandro\AppData\Roaming
CommonProgramFiles=C:\Program Files\Common Files
CommonProgramFiles(x86)=C:\Program Files (x86)\Common Files
CommonProgramW6432=C:\Program Files\Common Files
COMPUTERNAME=ASUS-B551L-09
ComSpec=C:\WINDOWS\system32\cmd.exe
configsetroot=C:\WINDOWS\ConfigSetRoot
DOCKER_TOOLBOX_INSTALL_PATH=C:\Program Files\Docker Toolbox
FPS_BROWSER_APP_PROFILE_STRING=Internet Explorer
FPS_BROWSER_USER_PROFILE_STRING=Default
FP_NO_HOST_CHECK=NO
HOMEDRIVE=C:
HOMEPATH=\Users\Alessandro
JAVA_HOME=C:\Program Files\Java\jdk1.8.0_65
LOCALAPPDATA=C:\Users\Alessandro\AppData\Local
LOGONSERVER=\\ASUS-B551L-09
NUMBER_OF_PROCESSORS=4
OS=Windows_NT
Path=C:\ProgramData\Oracle\Java\javapath;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\GTK2-Runtime\bin;C:\Program Files\TortoiseSVN\bin;C:\Program Files\Java\jdk1.8.0_65\bin;C:\Program Files\Git;C:\Program Files\7-Zip;C:\Program Files\nodejs\;C:\Program Files\Docker Toolbox;C:\Users\Alessandro\AppData\Roaming\npm
PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC
PROCESSOR_ARCHITECTURE=AMD64
PROCESSOR_IDENTIFIER=Intel64 Family 6 Model 69 Stepping 1, GenuineIntel
PROCESSOR_LEVEL=6
PROCESSOR_REVISION=4501
ProgramData=C:\ProgramData
ProgramFiles=C:\Program Files
ProgramFiles(x86)=C:\Program Files (x86)
ProgramW6432=C:\Program Files
PROMPT=$P$G
PSModulePath=C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules\
PUBLIC=C:\Users\Public
SESSIONNAME=Console
SystemDrive=C:
SystemRoot=C:\WINDOWS
TEMP=C:\Users\Alessandro\AppData\Local\Temp
TMP=C:\Users\Alessandro\AppData\Local\Temp
USERDOMAIN=ASUS-B551L-09
USERDOMAIN_ROAMINGPROFILE=ASUS-B551L-09
USERNAME=Alessandro
USERPROFILE=C:\Users\Alessandro
VBOX_MSI_INSTALL_PATH=C:\Program Files\Oracle\VirtualBox\
windir=C:\WINDOWS
回答1:
When started as a Windows service (in a typical Windows installation), Tomcat gets the JVM path from the Java tab, visible from systray/configure.
All Java paths for Tomcat depend on this main path.
I guess, the sense of such design is: after Java upgrade Tomcat can run with old, checked JVM, until admin modify.
回答2:
I guess JAVA_HOME variables is getting overridden by tomcat.
Please check startup.bat and catalina.bat files to check if JAVA_HOME variable is defined which I guess will be defined there.
Please check those files under tomcat bin folder.
回答3:
Thanks to Jacek Cz, I have found the solution.
This was the configuration of Tomcat, visible in the panel that can be launched from:
"Windows Icon / All Apps / Apache Tomcat 8 / Configure"
Going to the tab Java, there was setted the JDK 1.7. Changing this variable, Tomcat starts with the correct JDK.
来源：https://stackoverflow.com/questions/37180393/why-tomcat8-exe-starts-with-a-java-home-that-is-different-from-java-home-setted