📜  Java中的 LongBuffer reset() 方法及示例

📅  最后修改于: 2022-05-13 01:55:43.419000             🧑  作者: Mango

Java中的 LongBuffer reset() 方法及示例

Java.nio.LongBuffer 类的reset()方法用于将此缓冲区的位置重置为先前标记的位置。在此过程中,标记的值保持不变。

句法:

public final LongBuffer reset()

参数:此方法不接受任何参数。

返回值:此方法返回此缓冲区

以下是说明 reset() 方法的示例:

示例 1:

// Java program to demonstrate
// reset() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        try {
  
            long[] carr = { 10, 20, 30, 40 };
  
            // creating object of LongBuffer
            // and allocating size capacity
            LongBuffer cb = LongBuffer.wrap(carr);
  
            // try to set the position at index 2
            cb.position(2);
  
            // Set this buffer mark position
            // using mark() method
            cb.mark();
  
            // try to set the position at index 4
            cb.position(4);
  
            // display position
            System.out.println("position before reset: "
                               + cb.position());
  
            // try to call reset() to restore
            // to the position we marked
            cb.reset();
  
            // display position
            System.out.println("position after reset: "
                               + cb.position());
        }
  
        catch (InvalidMarkException e) {
            System.out.println("new position is less than "
                               + "the position we"
                               + " marked before ");
            System.out.println("Exception throws: " + e);
        }
    }
}
输出:
position before reset: 4
position after reset: 2

示例 2:

// Java program to demonstrate
// reset() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        try {
  
            long[] carr = { 10, 20, 30, 40 };
  
            // creating object of LongBuffer
            // and allocating size capacity
            LongBuffer cb = LongBuffer.wrap(carr);
  
            // try to set the position at index 2
            cb.position(2);
  
            // Set this buffer mark position
            // using mark() method
            cb.mark();
  
            // try to set the position at index 4
            cb.position(1);
  
            // display position
            System.out.println("position before reset: "
                               + cb.position());
  
            // try to call reset() to restore
            // to the position we marked
            cb.reset();
  
            // display position
            System.out.println("position after reset: "
                               + cb.position());
        }
  
        catch (InvalidMarkException e) {
            System.out.println("\nnew position is less than "
                               + "the position we"
                               + " marked before ");
            System.out.println("Exception throws: " + e);
        }
    }
}
输出:
position before reset: 1

new position is less than the position we marked before 
Exception throws: java.nio.InvalidMarkException

参考: https://docs.oracle.com/javase/9/docs/api/ Java/nio/LongBuffer.html#mark–