在服务器上设置 Tomcat 7：“注意：JAVA_HOME 应该指向 JDK 而不是 JRE”......为什么？

Question

I'm trying to set up Tomcat 6 on my server instance (Fresh install of Windows Server 2008 R2 Enterprise). I want to make a Java EE service available via a URL.

It works via localhost on the server. I put the .war file in my /webapps , run startup.bat in the /bin and then i navigated to localhost:80/myWebServce in my browser to get directed to my welcome page.

When I try to create a service by running service.bat (in the /bin folder)) I get an error message that says:

The JAVA_HOME environment variable is not defined correctly
This environment variable is needed to run this program
NB: JAVA_HOME should point to a JDK not a JRE

My question is: Why? I thought a JDK was just a JRE + Some development tools(an IDE, a debugger etc). Why does tomcat need a JDK To run as a service, but not on localhost? What's in a JDK that's needed to run a webservice?

Answer 1

remove semi-colon from the end of JRE_HOME / JAVA_HOME variables. there should not be semi-colon…

variable: JAVA_HOME value : C:\\Program Files\\Java\\jdk1.6.0 (note : no semicolon at the end)

variable: JRE_HOME value : C:\\Program Files\\Java\\jre1.6.0 (note : no semicolon at the end)

Apply above changes and run your tomcat successfully.

Answer 2

Tomcat does not require a JDK. Tomcat ships with the Eclipse JDT compiler which Tomcat uses as part of the *.jsp -> *.java -> *.class process to convert JSPs to compiled Servlets.

However, if you specify JAVA_HOME, Tomcat expects that to point to a full JDK installation. If you want to use a JRE then you need to set JRE_HOME rather than JAVA_HOME.

Answer 3

I had the same problem. Specified JRE_HOME and received the same error message. The error message persisted after I had removed the system environment variable JAVA_HOME and rebooted. Turned out my JRE path was actually incorrect, the error message was just confusing.

Answer 4

Web 容器需要 JDK 才能支持 JSP 等源代码的编译，因为 JDK 中存在编译器，因此它也需要相同的编译器。（这是它可能需要 JDK 的原因之一）

Answer 5

Make JAVA_HOME as system variable instead of environment variable, restart application(Tomcat). It should work fine.

Alternatively you might be facing same issue as discussed here

Answer 6

yes we require jdk inorder to run your requirement.. since you are providing .war file , we need jar command to extract contents from war,jar.. files. jar command is not found in JRE but only in JDK. if you wish you can checkout JDK,JRE. that is basic thing i observed apart from other things.

Answer 7

Check that the JAVA_HOME is set up correctly and if you have JDK installed create JRE_HOME for jre, JAVA_HOME would be set up for the JDK. Also alternate between "C:/Progra~1/..." and "C:/Program Files/..." to make sure the system is recognizing the path correctly