[英]java file readline returns null
I am trying to create a booking system in Java, however every time I run the program the while loop (shown below) skips straight to the end as though the line read was null 我试图用Java创建一个预订系统,但是每次我运行该程序时,while循环(如下所示)都直接跳到最后,就像读的行为空
//hardcoded file path - needs to be changed when program moved
String fileName = "C:\\Users\\BOO\\Desktop\\SystemsSoftwareBookingsystem\\FilmData.txt";
String line = null;
int readInt = 0;
float readFloat = 0;
int item_counter = 0;
try
{
BufferedReader bufferedReaderF = new BufferedReader(new FileReader(new File(fileName)));
while ((line = bufferedReaderF.readLine()) != null)
{
Film tmpFilm = new Film();
switch (item_counter)
{
case 0:
{
line = bufferedReaderF.readLine();
tmpFilm.name = line;
item_counter++;
break;
}
case 1:
{
readInt = bufferedReaderF.read();
tmpFilm.seatsTotal = readInt;
item_counter++;
break;
}
case 2:
{
readInt = bufferedReaderF.read();
tmpFilm.seatsAvailable = readInt;
item_counter++;
break;
}
case 3:
{
readInt = bufferedReaderF.read();
tmpFilm.price = readFloat;
item_counter++;
break;
}
case 4:
{
readInt = bufferedReaderF.read();
tmpFilm.showingTime = readFloat;
item_counter++;
break;
}
case 5:
{
readInt = bufferedReaderF.read();
tmpFilm.day = readInt;
item_counter++;
break;
}
case 6:
{
readInt = bufferedReaderF.read();
tmpFilm.month = readInt;
item_counter++;
break;
}
case 7:
{
readInt = bufferedReaderF.read();
tmpFilm.year = readInt;
item_counter = 0;
break;
}
}
line = bufferedReaderF.readLine();
server.filmList.add(tmpFilm);
}
bufferedReaderF.close();
} catch (FileNotFoundException ex)
{
System.out.println("Unable to open file '" + fileName + "'");
} catch (IOException ex)
{
System.out.println("Error reading file '" + fileName + "'");
}
}
}`
any ideas / help would be greatly appreciated 任何想法/帮助将不胜感激
EDIT added rest of the code in the while loop as requested EDIT根据请求在while循环中添加了其余代码
EDIT here is the file I am reading from 编辑这里是我正在读取的文件
Film 1
10
10
5.00
10.30
Wednesday 23rd
July
2013
I don't know if this is related to the problem, but you need to put break;
我不知道这是否与问题有关,但是您需要
break;
statements after every code sequence in your switch
. switch
每个代码序列之后的语句。 Otherwise, if say item_counter
is 0, it will execute the code for 0, and then fall through and execute the code for 1, and then for 2, etc. 否则,如果说
item_counter
为0,它将执行0的代码,然后掉落并执行1的代码,然后执行2的代码, item_counter
。
Remove- 去掉-
line = bufferedReaderF.readLine();
And read in the loop- 并在循环中阅读-
while ((line = bufferedReaderF.readLine()) != null)
Check if the file is empty. 检查文件是否为空。 Can you also update your question with code inside while?
您还能在一段时间内用代码更新您的问题吗?
Based from your edit- 根据您的修改-
You are ignoring what you are reading in while. 您正在忽略自己正在阅读的内容。 Should be something like this-
应该是这样的-
switch (item_counter)
{
case 0:
{
tmpFilm.name = line;
item_counter++;
break;
}
case 1:
{
tmpFilm.seatsTotal = Integer.parseInt(line);
item_counter++;
break;
}
...etc...
Try this... 尝试这个...
BufferedReader bufferedReaderF = new BufferedReader(new FileReader(new File(fileName)));
line = bufferedReaderF.readLine();
while (line != null)
{
Film tmpFilm = new Film();
switch (item_counter)
{
case 0:
{
// line = bufferedReaderF.readLine();
tmpFilm.name = line;
item_counter++;
break;
}
case 1:
{
readInt=Integer.parseInt(line);
tmpFilm.seatsTotal = readInt;
item_counter++;
break;
}
case 2:
{
readInt = Integer.parseInt(line);
tmpFilm.seatsAvailable = readInt;
item_counter++;
break;
}
case 3:
{
readFloat=Float.parseFloat(line);
tmpFilm.price = readFloat;
item_counter++;
break;
}
case 4:
{
readFloat=Float.parseFloat(line);
tmpFilm.showingTime = readFloat;
item_counter++;
break;
}
case 5:
{
line=line.replaceAll("\\D","");
readInt = Integer.parseInt(line);
tmpFilm.day = readInt;
item_counter++;
break;
}
case 6:
{
readInt = Integer.parseInt(GregorianCalendar.class.getField(line.toUpperCase()).get(line))+1;
tmpFilm.month = readInt;
item_counter++;
break;
}
case 7:
{
readInt = Integer.parseInt(line);
tmpFilm.year = readInt;
item_counter = 0;
}
}
line = bufferedReaderF.readLine();
server.filmList.add(tmpFilm);
}
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