samples/find_max_lines.js

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// Find the file with maximum number of lines

var Files = Java.type("java.nio.file.Files");
var Integer = Java.type("java.lang.Integer");
var Paths = Java.type("java.nio.file.Paths");

var file = arguments.length == 0? "." : arguments[0];
var ext = arguments.length > 1? arguments[1] : ".java";
var path = Paths.get(file);

// return number of lines in given Path (that represents a file)
function lines(p) {
    var strm = Files.lines(p);
    try {
        return strm.count();
    } finally {
        strm.close();
    }
}

// walk files, map to file and lines, find the max    
var obj = Files.find(path, Integer.MAX_VALUE, 
    function(p, a) !p.toFile().isDirectory() && p.toString().endsWith(ext)).
map(function(p) ({ path : p, lines: lines(p) })).
max(function(x, y) x.lines - y.lines).get();

// print path and lines of the max line file
print(obj.path, obj.lines);