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尝试final project for my friend's ICS class时，我遇到了这个奇怪的错误。为什么使用Scanner.next（）会导致这种奇怪的System.out.println（）行为？
其中一项任务是阅读this CSV file。这是我如何做它用扫描仪短SSCCE：
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class Test {
public static void main(String[] args) {
Scanner fileScanner;
String inputFile = "input-project.csv";
try {
fileScanner = new Scanner(new File(inputFile));
fileScanner.useDelimiter("[,\n]");
fileScanner.nextLine();
while(fileScanner.hasNext()) {
String name = fileScanner.next();
String number = fileScanner.next();
System.out.println("Inserting " + name + " " + number + " (" + hash(name) + ")");
//telephoneBook.insert(name, number);
}
fileScanner.close();
} catch (FileNotFoundException e) {
System.out.println("ERROR: Input file " + inputFile + " was not found");
}
}
public static Integer hash(String name) {
return name.hashCode() % 7;
}
}
它读取正常，但由于某些原因System.out.println("Inserting " + name + " " + number + " (" + hash(name) + ")")只打印" (" + hash(name) + ")"。
看看这样的输出：
(5)
(1)
(4)
(5)
(3)
(1)
(4)
(2)
(2)
(2)
Process finished with exit code 0
虽然与代码玩弄试图解决这个问题，我结束了不使用fileScanner.next()通过修复它。这是我目前的工作例如：
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class Test {
public static void main(String[] args) {
Scanner fileScanner;
String inputFile = "input-project.csv";
try {
fileScanner = new Scanner(new File(inputFile));
//fileScanner.useDelimiter("[,\n]");
fileScanner.nextLine(); // skip the first line
while(fileScanner.hasNext()) {
String[] line = fileScanner.nextLine().split(",");
String name = line[0];
String number = line[1];
//String name = fileScanner.next();
//String number = fileScanner.next();
System.out.println("Inserting " + name + " " + number + " (" + hash(name) + ")");
//telephoneBook.insert(name, number);
}
fileScanner.close();
} catch (FileNotFoundException e) {
System.out.println("ERROR: Input file " + inputFile + " was not found");
}
}
public static Integer hash(String name) {
return name.hashCode() % 7;
}
}
这打印出预期：
Inserting HALL 123-4566 (5)
Inserting BAKER 111-1111 (1)
Inserting CARTER 222-2222 (4)
Inserting KING 555-5555 (5)
Inserting FOX 666-6666 (3)
Inserting LEE 777-7777 (1)
Inserting CASTRO 888-8888 (4)
Inserting DAVIS 999-9999 (2)
Inserting LONG 987-1234 (2)
Inserting KAM 654-7890 (2)
Process finished with exit code 0
我现在的问题是：为什么这个解决这一问题？我错误地使用了.next()方法吗？