Java 扫描器与 2 hasNext()

Question

我想从 CSV 文件恢复对象。我需要知道扫描仪是否有 2 个下一个值:scanner.hasNext()

问题是我的访问构造函数有两个参数，我需要确保我的 csv 文件中至少还剩下 2 个。

相关代码如下:

    /**
 * method to restore a pet from a CSV file.  
 * @param fileName  the file to be used as input.  
 * @throws FileNotFoundException if the input file cannot be located
 * @throws IOException if there is a problem with the file
 * @throws DataFormatException if the input string is malformed
 */
public void fromCSV(final String fileName)
throws FileNotFoundException, IOException, DataFormatException
{
    FileReader inStream = new FileReader(fileName);
    BufferedReader in = new BufferedReader(inStream);
    String data = in.readLine();
    Scanner scan = new Scanner(data);
    scan.useDelimiter(",");
    this.setOwner(scan.next());
    this.setName(scan.next());
    while (scan.hasNext()) {
        Visit v = new Visit(scan.next(), scan.next());
        this.remember(v);
    }
    inStream.close();
}

提前致谢

Answer 1

hasNext() 也可以采用一个模式，这提供了一种很好的方法来检查这一点:

String pattern = ".*,.*";
while (scan.hasNext(pattern)) {
  ...
}