如何检查包含特殊字符的行？

Question

Hi I have a file stored in Linux system that contains a special character ^C Something like this:

ABCDEF^CIJKLMN Now i need to read this file in java and detect that there is this ^C to make split. The problem that to read the file in UNIX.I must use cat -v fileName to see the special chracter ^C elsewhere i can't see it. This is my sample code.

    InputStreamReader inputStreamReader = new InputStreamReader(new FileInputStream(this),
            Charset.forName("UTF-8"));

    BufferedReader br = new BufferedReader(inputStreamReader);
    String line;
    while ((line = br.readLine()) != null) {
        if (line.contains("^C")) {
            String[] split = line.split("\\" + sepRecord);
            System.out.println(split);

    }

Answer 1

You are checking if the line contains the String "^C", not the character '^C' (which corresponds to 0x03 , or \ ). You should search for the character 0x03 instead. Here's a code example that would work in your case:

byte[] fileContent = new byte[] {'A', 0x03, 'B'};
String fileContentStr = new String (fileContent);
System.out.println (fileContentStr.contains ("^C")); // false
System.out.println (fileContentStr.contains (String.valueOf ((char) 0x03))); // true
System.out.println (fileContentStr.contains ("\u0003")); // true, thanks to @Thomas Fritsch for the precision

String[] split = fileContentStr.split ("\u0003");
System.out.println (split.length); // 2
System.out.println (split[0]); // A
System.out.println (split[1]); // B

The ^C character is displayed in Caret Notation , and must be interpreted as a single character.