Question

我想读取文本文件，然后获取读取文件的偏移量。我尝试了以下程序，但事情是我不想使用RandomAccessFile，我该怎么做。

RandomAccessFile access = null;
                try {
                    access = new RandomAccessFile(file, "r");

                    if (file.length() < addFileLen) {
                        access.seek(file.length());
                    } else {
                        access.seek(addFileLen);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
                String line = null;
                try {

                    while ((line = access.readLine()) != null) {

                        System.out.println(line);
                        addFileLen = file.length();

                    }

Answer 1

如果要连续阅读文件，可以执行以下操作。这通过实际上不读取文件的末尾。您遇到的问题是，最后可能没有完整的行甚至是完整的多字节字符。

class FileUpdater {
    private static final long MAX_SIZE = 64 * 1024;
    private static final byte[] NO_BYTES = {};

    private final FileInputStream in;
    private long readSoFar = 0;

    public FileUpdater(File file) throws FileNotFoundException {
        this.in = new FileInputStream(file);
    }

    public byte[] read() throws IOException {
        long size = in.getChannel().size();
        long toRead = size - readSoFar;
        if (toRead > MAX_SIZE)
            toRead = MAX_SIZE;
        if (toRead == 0)
            return NO_BYTES;
        byte[] bytes = new byte[(int) toRead];
        in.read(bytes);
        readSoFar += toRead;
        return bytes;
    }    
}

读取文件然后跳转到结束

1 个答案: