I am using jetty-9.1.1.v20140108 and tried to start jetty service through the command line showing me the following error. for this, using the JRE "1.7.0_02".
java.io.IOException: Cannot read file: modules\npn\npn-1.7.0_02.mod
at org.eclipse.jetty.start.Modules.registerModule(Modules.java:405)
at org.eclipse.jetty.start.Modules.registerAll(Modules.java:395)
at org.eclipse.jetty.start.Main.processCommandLine(Main.java:561)
at org.eclipse.jetty.start.Main.main(Main.java:102)
Jetty is looking for a .mod file corresponding to the version of the JRE you are using, but it isn't included in your distribution of Jetty.
In your Jetty/modules/npn directory, make a copy of "npn-1.7.0_04.mod" and name it "npn-1.7.0_02.mod".
Open the file in a text editor and replace all occurrences of "1.1.0.v20120525" with "1.0.0.v20120402".
See http://www.eclipse.org/jetty/documentation/current/npn-chapter.html#npn-versions for more information.
We found the same problem on Windows Server 2008. It happens when Jetty is trying to read the module configuration files and is due to a fault in the check for readability.
In the jetty source file FS.java line 39 a check is made using java.nio, to see if the file is readable:
The call to isReadable is slow and fails, see also: http://mail.openjdk.java.net/pipermail/nio-discuss/2012-July/000672.html
The file itself is in fact readable and can be successfully read from Java, but the isReadable incorrectly returns false.
There are two possible workarounds:
(See also similar question Jetty Web Server unable to start "java.io.IOException: cannot read file:..")