Question

I have a Ruby code that reads file line-by-line and checks if it needs to read the next line to some block or it should handle that block and continue reading file parsing each line.

Here’s it:

File.open(ARGV[0], 'rb') do |f|
    fl = false
    text = ''

    f.readlines.each do |line|
        if (line =~ /^end_block/)
            fl = false

            # parse text variable
        end

        text += line if fl == true

        if (line =~ /^start_block/)
            fl = true
        end
    end
end

E.g. i need the file to be opened for reading as binary and still i need a readLine method.

So, the question is: how can i do exactly the same with Groovy/Java?

Answer 1

You can use java.io.DataInputStream which provides both a readLine() method and readFully(byte[]) and read(byte[]) methods.

Warning: The JavaDoc for readLine says, it is deprecated and that the encoding might be inappropriate (read details in JavaDoc).

So think twice about your real requirements and if this is a suitable trade-off in your case.