How to change Java version used by TOMCAT?

Question

I have Java 1.6 and Tomcat 5.5 installed on my system.

But Tomcat 5.5 accesses Java 1.5 and hence as the outcome I get the error Bad version number in .class file while executing java code with JSP.

How can I change the Tomcat version to Java 1.6?

UPDATE

I tried changing the JVM that the tomcat5w.exe is pointing to the version 1.6 and now I am out of the Bad version in .class file error. But now, I get the following error.

exception  org.apache.jasper.JasperException org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:498) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:411) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:308) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:259) javax.servlet.http.HttpServlet.service(HttpServlet.java:729)  root cause  java.lang.NullPointerException myfirst.SearchLink.checkURL(SearchLink.java:20) org.apache.jsp.Test_jsp._jspService(Test_jsp.java:52) org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98) javax.servlet.http.HttpServlet.service(HttpServlet.java:729) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:308) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:259) javax.servlet.http.HttpServlet.service(HttpServlet.java:729) 

What might be the root cause?

Answer 1

When you open catalina.sh / catalina.bat, you can see :

Environment Variable Prequisites

JAVA_HOME Must point at your Java Development Kit installation.

So, set your environment variable JAVA_HOME to point to Java 6. Also make sure JRE_HOME is pointing to the same target, if it is set.

Update: since you are on Windows, see here for how to manage your environment variables

Answer 2

You can change the JDK or JRE location using the following steps:

1. open the terminal or cmd.
   
2. go to the [tomcat-home]\bin directory.
   ex: c:\tomcat8\bin
3. write the following command: Tomcat8W //ES//Tomcat8
4. will open dialog, select the java tab(top pane).
5. change the Java virtual Machine value.
6. click OK.

note: in Apache TomEE same steps, but step (3) the command must be: TomEE //ES