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Android Scanner Delimiter Issues

开发者 https://www.devze.com 2023-02-07 16:09 出处:网络
Ok, the other day I had trouble with the FileWriter notding the newline, but I got some help with that and solved it. Now, just like befo开发者_如何学运维re, I cpoied some old code of mine (works perf

Ok, the other day I had trouble with the FileWriter notding the newline, but I got some help with that and solved it. Now, just like befo开发者_如何学运维re, I cpoied some old code of mine (works perfectly in the old prgram) to read the file that's written. I use "|" as a delimiter (pieces.useDelimiter("|");). When I call pieces.next() it only teakes the next character, not the next string up to the delimiter. What am I missing? Code snippet:

try{
    mFile = new Scanner(newFile(loadPath));
    while(mFile.hasNextLine()){
        String input = mFile.nextLine();
        Scanner pieces = new Scanner(input);
        pieces.useDelimiter("|");
        while(pieces.hasNext()){
            int row = Integer.valueOf(pieces.next());
            int col = Integer.valueOf(pieces.next());
            String pullPath = pieces.next();
            ......

}}


The String that you pass to useDelimiter is interpreted as a regular expression. | is a special character in regular expressions, so you have to escape it with a backslash. And the backslash itself needs to be escaped, in order to get past the Java compiler. So changing that line as follows should do the trick:

    pieces.useDelimiter("\\|");

Also, note that the string returned by pieces.next() includes the delimiter. I suspect that these lines:

        int row = Integer.valueOf(pieces.next());
        int col = Integer.valueOf(pieces.next());

could be replaced by:

        int row = pieces.nextInt();
        int col = pieces.nextInt();

You may also need to adjust pullPath to trim the delimiter(s).

I hope this helps.

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