您可以使用以下代码片段：

new File('/path/to/folder/with/your/duplicate/files').listFiles().each { file ->
    List<String> lines = file.readLines()
    new File('/path/to/folder/with/your/duplicate/files').listFiles(new FilenameFilter() {
        @Override
        boolean accept(File dir, String name) {
            return !file.getName().equals(name)
        }
    }).each { otherfile ->
        List<String> otherLines = otherfile.readLines()
        lines.each { line ->
            if (otherLines.contains(line)) {
                new File('Double Duplicate.txt') << line << ' ('<< file.getName() << ' & ' << otherfile.getName() << ')' << System.getProperty('line.separator')
            }
        }
    }
}

更多信息：

• Apache Groovy - Why and How You Should Use It