Java中的 IntBuffer flip() 方法及示例

Java.nio.IntBuffer 类的flip()方法用于翻转这个缓冲区。通过翻转这个缓冲区，这意味着缓冲区将被修剪到当前位置，然后该位置将变为零。在此过程中，如果缓冲区上有任何标记，则该标记将被自动丢弃。

句法：

public final IntBuffer flip()

参数：该方法不带任何参数。

返回值：该方法返回翻转后的 IntBuffer 实例。

以下是说明翻转（）方法的示例：

示例 1：

// Java program to demonstrate
// flip() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // Declare and initialize
        // the int array
        int[] ib
            = { 10, 20, 30 };
  
        // wrap the int array
        // into IntBuffer
        // using wrap() method
        IntBuffer intBuffer
            = IntBuffer.wrap(ib);
  
        // set position at index 1
        intBuffer.position(1);
  
        // print the buffer
        System.out.println(
            "Buffer before flip: "
            + Arrays.toString(
                  intBuffer.array())
            + "\nPosition: "
            + intBuffer.position()
            + "\nLimit: "
            + intBuffer.limit());
  
        // Flip the Buffer
        // using flip() method
        intBuffer.flip();
  
        // print the buffer
        System.out.println(
            "\nBuffer after flip: "
            + Arrays.toString(
                  intBuffer.array())
            + "\nPosition: "
            + intBuffer.position()
            + "\nLimit: "
            + intBuffer.limit());
    }
}

输出：

Buffer before flip: [10, 20, 30]
Position: 1
Limit: 3

Buffer after flip: [10, 20, 30]
Position: 0
Limit: 1

示例 2：

// Java program to demonstrate
// flip() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // defining and allocating IntBuffer
        // using allocate() method
        IntBuffer intBuffer
            = IntBuffer.allocate(4);
  
        // put int value in IntBuffer
        // using put() method
        intBuffer.put(20);
        intBuffer.put(34);
  
        // set position at index 1
        intBuffer.position(1);
  
        // print the buffer
        System.out.println(
            "Buffer before flip: "
            + Arrays.toString(
                  intBuffer.array())
            + "\nPosition: "
            + intBuffer.position()
            + "\nLimit: "
            + intBuffer.limit());
  
        // Flip the Buffer
        // using flip() method
        intBuffer.flip();
  
        // print the buffer
        System.out.println(
            "\nBuffer after flip: "
            + Arrays.toString(
                  intBuffer.array())
            + "\nPosition: "
            + intBuffer.position()
            + "\nLimit: "
            + intBuffer.limit());
    }
}

输出：

Buffer before flip: [20, 34, 0, 0]
Position: 1
Limit: 4

Buffer after flip: [20, 34, 0, 0]
Position: 0
Limit: 1

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