3

I have a Unicode file that needs to be exported to database(Vertica). The column delimiter is CTRL+B, record delimiter is newline(\n). Whenever there is a newline within a column value, CTRL+A is used as escape character.

When I use BufferedReader.readLine() to read this file, the records with ID's 2 and 4, are read as two records. Whereas I want to read them as a single whole record as given in output.

Here is the example input file. | stands for CTRL+B and ^ stands for CTRL+A.

Input
ID|Name|Job Desc
----------------
1|xxxx|SO Job
2|YYYY|SO Careers^
Job
3|RRRRR|SO
4|ZZZZ^
 ZZ|SO Job
5|AAAA|YU

Output:
ID|Name|Job Desc
----------------
1|xxxx|SO Job
2|YYYY|SO Careers Job
3|RRRRR|SO
4|ZZZZ ZZ|SO Job
5|AAAA|YU

The file is huge, so I cant use StringEscapeUtils. Any suggestions on this?

4

2 回答 2

2

您可以将 aScanner与自定义分隔符一起使用。我使用的分隔符设置为匹配\n \u0001\n匹配(其中\u0001代表CTRL+A):

try {
    PrintWriter writer = new PrintWriter("dboutput.txt");
    Scanner sc = new Scanner(new File("dbinput.txt"));
    sc.useDelimiter(Pattern.compile("^(?!.*(\\u0001\\n)).*\\n$"));
    while (sc.hasNext()) {
        writer.println(sc.next());
    }
    scanner.close();
    writer.close();
} catch (FileNotFoundException e) {
   e.printStackTrace();
} 
于 2015-04-28T02:15:10.733 回答
0

蒂姆的回答部分正确。但是,它仍然无法解析由 CTRL+A 转义的换行符。

这是我的解决方案(由蒂姆回答指导)

File f = new File("C:\\Users\\SV7104\\Desktop\\sampletest.txt");
Scanner sc = new Scanner(f).useDelimiter(Pattern.compile("\\s*\\u0002\\n\\s*"));
            while (sc.hasNext()) {
                System.out.print(1);
                System.out.println(sc.next().toString().replaceAll("\\u0001\\n", " "));

            }

如果还有其他有效的方法,我也很想知道。

于 2015-04-28T19:50:17.903 回答