Flash cards
Review the key moves
What is the main idea behind Java Scanner close() Method?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
import java.io.File; // Import the File ___Put the learning moves in the order that makes the concept easiest to apply.
❮ Scanner Methods
Example
Use the close() method when finished reading from a file:
import java.io.File; // Import the File class
import java.io.FileNotFoundException; // Import this class to handle errors
import java.util.Scanner; // Import the Scanner class to read text files
public class ReadFile {
public static void main(String[] args) {
try {
File myObj = new File("filename.txt");
Scanner myReader = new Scanner(myObj);
while (myReader.hasNextLine()) {
String data = myReader.nextLine();
System.out.println(data);
}
myReader.close();
} catch (FileNotFoundException e) {
System.out.println("An error occurred.");
e.printStackTrace();
}
}
}Definition and Usage
The close() method closes the file or input stream that the scanner was reading. After calling the close() method, the current Scanner object can no longer be used.
Note
Closing a scanner that was created with System.in will close the System.in stream itself, making it unusable. It is best to only used the close() method with files.
Syntax
public void close()Related Pages
Java Tutorial: Create and Write Files .
❮ Scanner Methods