[英]Scanner won't read the next line from a file. JAVA
Like the title says, I can get it to write the first thing to the file I want it to, but after that it doesn't write any more. 就像标题所说的那样,我可以将第一件事写到我想要的文件中,但是之后就不再写了。 I run it through the debugger, and see that it's not even reading the next line (I know this because it's not filling the array.) I tried manually advancing the pointer (I don't know if that's actually a thing you can do) at the end of the loop with "line = in.readline;", but It just throws a "nosuchelement" exception.
我通过调试器运行它,发现它甚至没有读取下一行(我知道这一点,因为它没有填充数组。)我尝试手动推进指针(我不知道那是否实际上是您可以做的事情)在循环的末尾添加了“ line = in.readline;”,但它只是抛出了“ nosuchelement”异常。 Here's my try block"
这是我的尝试块”
try
{
in = new BufferedReader(new FileReader("lab7input.txt"));
outNormal = new PrintWriter(new File("normal.txt"));
outVegetarian = new PrintWriter(new File("vegetarian.txt"));
outPescetarian = new PrintWriter(new File("pescetarian.txt"));
outInvalid = new PrintWriter(new File("invalid.txt"));
String line = in.readLine();
StringTokenizer st = new StringTokenizer(line);
while (line != null)
{
Scanner sc = new Scanner(line);
while(sc.hasNext())
{
if(st.countTokens() == 3)
{
attendee3[0] = sc.next();
attendee3[1] = sc.next();
attendee3[2] = sc.next();
if(Integer.parseInt(attendee3[2]) == 0)
{
outNormal.println(attendee3[0] + " " + attendee3[1]);
outNormal.close();
}
else if(Integer.parseInt(attendee3[2]) == 1)
{
outVegetarian.println(attendee3[0] + " " + attendee3[1]);
outVegetarian.close();
}
else if(Integer.parseInt(attendee3[2]) == 2)
{
outPescetarian.println(attendee3[0] + " " + attendee3[1]);
outPescetarian.close();
}
else
{
outInvalid.println(attendee3[0] + " " + attendee3[1]);
outInvalid.close();
}
}
if(st.countTokens() == 4)
{
attendee4[0] = sc.next();
attendee4[1] = sc.next();
attendee4[2] = sc.next();
if(Integer.parseInt(attendee4[3]) == 0)
{
outNormal.println(attendee4[0] + " " + attendee4[1] + " " + attendee4[2]);
outNormal.close();
}
else if(Integer.parseInt(attendee4[3]) == 1)
{
outVegetarian.println(attendee4[0] + " " + attendee4[1] + " " + attendee4[2]);
outVegetarian.close();
}
else if(Integer.parseInt(attendee4[3]) == 2)
{
outPescetarian.println(attendee4[0] + " " + attendee4[1] + " " + attendee4[2]);
outPescetarian.close();
}
else
{
outInvalid.println(attendee4[0] + " " + attendee4[1] + " " + attendee4[2]);
outInvalid.close();
}
}
//line = in.readLine();
}
}
}
a simpler and cleaner way would be 一个更简单,更清洁的方法是
String line = in.readLine();
while (line != null)
{
String arr [] = line.split ();
if(arr.length == 3)
{
attendee3[0] = arr[0];
attendee3[1] = arr[1];
attendee3[2] = arr[2];
}
// other count code
line = in.readLine();
}
您必须将line = in.readLine()
放在下面的一个块中,而不是放在扫描仪的while块中。
Not only that, i've had the experience that Scanner can only read in UTF-8 codeded .txt files. 不仅如此,我还具有Scanner只能读取UTF-8编码的.txt文件的经验。 so always make sure that they are UTF-8 coded.
因此,请务必确保它们均采用UTF-8编码。
If they are not just simply open the file and save it with that coding. 如果不是,只需打开文件并使用该代码保存即可。
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