CODEWITHSUNDEEP
javajava.util.scannerdelimiter
Quentin
Quentin

Reputation: 1086

Java Scanner - two delimiters and exception

I want to read a file which has the following form:

c00004;Doe John;bananas;4.0;50.0
c00003;Doe John;milk;4.0;5.0
c00001;Doe John;milk;4.0;10.0
c00001;Doe John;milk;5.0;2.0

And with this code:

Scanner in = new Scanner(Paths.get(fileName));
in.useDelimiter(";|\\s");

while(in.hasNext())
{
    String customerID = in.next();
    String surname = in.next();
    String firstName = in.next();
    String productName = in.next();
    double price = in.nextDouble();
    double quantity = in.nextDouble();

    Purchase newPurchase = new Purchase(customerID, surname, firstName, productName, price, quantity);
}

in.close();

I get an Input Mismatch Exception in the middle of reading the second line of data. Any ideas why is that?

EDIT: If I output every variable after having read it, the output is:

c00004 Doe John bananas 4.0 50.0 
 c00003 Doe John Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Scanner.java:864)
    at java.util.Scanner.next(Scanner.java:1485)
    at java.util.Scanner.nextDouble(Scanner.java:2413)
    at CustomersPurchaseSortFind.readFile(CustomersPurchaseSortFind.java:31)
    at Main.main(Main.java:9)

Upvotes: 1

Views: 420

Answers (2)

chengpohi
chengpohi

Reputation: 14217

Your regex should be:

in.useDelimiter(";|\\s+");

because your data has \r in Windows with new line \n in the end of line, In the second loop, the delimiter will include \r character as an element:

    int i = 1;
    while(in.hasNext())
    {
        System.out.println("line: " + i++);
        String customerID = in.next();
        String surname = in.next();
        String firstName = in.next();
        String productName = in.next();
        double price = in.nextDouble();
        System.out.println("Price: " + price);
        double quantity = in.nextDouble();
    }

The output:

line: 1
customerID: c00004
Price: 4.0
line: 2
customerID: 
Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Scanner.java:909)
    at java.util.Scanner.next(Scanner.java:1530)
    at java.util.Scanner.nextDouble(Scanner.java:2456)
    at Test.main(Test.java:32)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

the exception is actual throwed by the second loop to parse double.

we can see the second customerID is empty.

and for the second loop the Price value is: milk, so it will throw InputMismatchException for Double parse

Upvotes: 2

nafas
nafas

Reputation: 5423

Alternatively just read the whole line then use split:

String nextLine=in.nextLine();
String[] splitted= nextLine.split(";|\\s");

Upvotes: 2

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