如何将jdk-8u74-linux-x64.rpm转换为1.8.0_74以检查Java版本？

Question

I am installing jdk-8u74-linux-x64.rpm on the server using a script. To download, I have parameters names like this:

"java": {
    "version": "8u74",
    "minor_version": "b02"
}

How can I use these these two parameters to verify if java is installed or not? I do not want to introduce another parameter like java_version=1.8.0_74-b02 . Any suggestions?

Answer 1

With ruby you can solve your problem. You can use below code to do that:-

def parse_app_name (filename, minor_version)
    file_name = filename.split('/')[-1]
    if file_name =~ /^(jre|jdk).*$/
      major_num = file_name.scan(/\d/)[0]
      update_num = file_name.scan(/\d+/)[1]
      # pad a single digit number with a zero
        if update_num.length < 2
          update_num = "0" + update_num
        end
      app_name = "1.#{major_num}.0_#{update_num}" + "-" + minor_version
    else
      puts "error"
    end
    return app_name
end

Execute:

puts parse_app_name("jdk-8u92-linux-x64.rpm", "b14")

Output:

1.8.0_92-b14

Existing java version:

$ java -version
 java version "1.8.0_92"
 Java(TM) SE Runtime Environment (build 1.8.0_92-b14)
 Java HotSpot(TM) 64-Bit Server VM (build 25.92-b14, mixed mode)

Checking the existing java Version:

system('java -version', :out => ['/tmp/log', 'a'], :err => ['/tmp/log', 'a'])
puts File.read("/tmp/log").split("\n")[1].scan(/\d.*/)[0].chomp(")").eql? parse_app_name("jdk-8u92-linux-x64.rpm", "b14")

Output:

true