Question

I’ve wrote a java code and compiled it. (foo1.6.class)
According to my search, my local machine has Java 1.6, and the tomcat server that I uploaded foo1.6.class only accepts version number 1.5 This means that I have to have Java 1.5 to compile?

I believe it is the cause that bad version number error is thrown like below.

My question is, is there any way I can compile my Java file using 1.5 version number?
Looked at javac cmd but seems like it is not part of the option. But I don’t think remove 1.6 and install Java 1.5 for this reason is not really good option neither. How do people deal with this kind of situation?

Thanks in advance!

exception

javax.servlet.ServletException: Bad version number in .class file (unable to load class resume_builder.ResumeBuilder)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:273)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

root cause

java.lang.UnsupportedClassVersionError: Bad version number in .class file (unable to load class resume_builder.ResumeBuilder)
    org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1884)
    org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:889)
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1353)
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1232)
    org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:128)
    org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:66)
    java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
    java.lang.Class.getDeclaredConstructors0(Native Method)
    java.lang.Class.privateGetDeclaredConstructors(Class.java:2357)
    java.lang.Class.getConstructor0(Class.java:2671)
    java.lang.Class.newInstance0(Class.java:321)
    java.lang.Class.newInstance(Class.java:303)
    org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:142)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:311)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

Answer 1

You can use javac -target 1.5 -source 1.5.

The Java compiler allows you to use a lower than it’s current target version number only if you also use a source compatibility version that is not higher than the target (there are execptions for source versions below 1.4).