Java Scanner close()用法及代码示例

java.util.Scanner类的close()方法关闭已打开的扫描器。如果扫描仪已经关闭，则在调用此方法时将无效。

用法:

public void close()

返回值：该函数不返回任何值。

以下示例程序旨在说明上述函数：

示例1:

// Java program to illustrate the 
// close() method of Scanner class in Java 
  
import java.util.*; 
  
public class GFG1 { 
    public static void main(String[] argv) 
        throws Exception 
    { 
  
        try { 
  
            // Get the string 
            String s = "Geeksforgeeks has Scanner Class Methods"; 
  
            // create a new scanner 
            // with the specified String Object 
            Scanner scanner = new Scanner(s); 
  
            // print the next line of the string 
            System.out.println("Scanner: "
                               + scanner.nextLine()); 
  
            // close the scanner 
            scanner.close(); 
  
            System.out.println("\nScanner Closed.\n"); 
  
            System.out.println("Trying to use scanner"
                               + " after closing."); 
  
            // print the next line of the string 
            System.out.println(scanner.nextLine()); 
        } 
  
        catch (Exception e) { 
            System.out.println("Exception thrown:\n" + e); 
        } 
    } 
}

输出：

Scanner: Geeksforgeeks has Scanner Class Methods

Scanner Closed.

Trying to use scanner after closing.
Exception thrown:
java.lang.IllegalStateException: Scanner closed

参考： https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#close()

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注：本文由纯净天空筛选整理自gopaldave大神的英文原创作品 Scanner close() method in Java with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。