在读取文件时使用分隔符

Question

我几乎没有使用分隔符的经验,我需要读取一个文本文件,该文件存储多个对象,其数据以逗号(",")分隔的单行存储.然后使用单独的字符串创建一个添加到arraylist的新对象.

Amadeus,Drama,160 Mins.,1984,14.83
As Good As It Gets,Drama,139 Mins.,1998,11.3
Batman,Action,126 Mins.,1989,10.15
Billy Elliot,Drama,111 Mins.,2001,10.23
Blade Runner,Science Fiction,117 Mins.,1982,11.98
Shadowlands,Drama,133 Mins.,1993,9.89
Shrek,Animation,93 Mins,2001,15.99
Snatch,Action,103 Mins,2001,20.67
The Lord of the Rings,Fantasy,178 Mins,2001,25.87

我使用Scanner读取文件,但是我发现没有找到行错误,整个文件存储在一个字符串中:

Scanner read = new Scanner (new File("datafile.txt"));
read.useDelimiter(",");
String title, category, runningTime, year, price;

while (read.hasNext())
{
   title = read.nextLine();
   category = read.nextLine();
   runningTime = read.nextLine();
   year = read.nextLine();
   price = read.nextLine();
   System.out.println(title + " " + category + " " + runningTime + " " +
                      year + " " + price + "\n"); // just for debugging
}
read.close();

Answer 1

使用read.next()而不是read.nextLine()

   title = read.next();
   category = read.next();
   runningTime = read.next();
   year = read.next();
   price = read.next();

Answer 2

我想你想调用.next()它返回一个 String 而不是.nextLine(). 您的.nextLine()呼叫正在越过当前线路。

Scanner read = new Scanner (new File("datafile.txt"));
   read.useDelimiter(",");
   String title, category, runningTime, year, price;

   while(read.hasNext())
   {
       title = read.next();
       category = read.next();
       runningTime = read.next();
       year = read.next();
       price = read.next();
     System.out.println(title + " " + category + " " + runningTime + " " + year + " " + price + "\n"); //just for debugging
   }
   read.close();

Answer 3

其中一个问题是：

while(read.hasNext())
   {
       title = read.nextLine();
       category = read.nextLine();
       runningTime = read.nextLine();

hasNext()

如果此扫描器的输入中有另一个标记，则返回 true。不是整条线。您需要使用hasNextLine()

您执行了三次 nextLine() 。我认为你需要做的是，阅读该行并拆分该行。