Error while making a whole-web searching

[NamNH <n....@gmail.com>]

I have a whole-web searching with the instructions from Nutch web site with
subset set to 500 and 10 iterations (round). After some hours when the first
round is done, I get this message in my log file:
**
Exception in thread "main" java.lang.UnsupportedClassVersionError:
org/apache/nutch/tools/UpdateDatabaseTool (Unsupported major.minor version
49.0)
    at java.lang.ClassLoader.defineClass0(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java
:123)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)

then immediately it comes to next round. Moreover, for all the rest rounds,
this message also appears. Could some one please guide me through this? Any
help is greatly appreciated. Thank you.
-- 
NamNH
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