java.nio.LongBuffer类的rewind()方法用于倒带此缓冲区。通过倒带此Buffer，可以执行以下操作：

当前位置设置为零

如果有标记，则将其丢弃，但标记值不变。

用法:

public LongBuffer rewind()

参数：此方法不接受任何参数。

返回值：倒带后，此方法返回此缓冲区。

下面是说明rewind()方法的示例：

范例1：

// Java program to demonstrate

// rewind() method

import java.nio.*;

import java.util.*;

public class GFG {

public static void main(String[] args)

{

// defining and allocating LongBuffer

// using allocate() method

LongBuffer longBuffer = LongBuffer.allocate(4);

// put long value in longBuffer

// using put() method

longBuffer.put(10);

longBuffer.put(20);

// print the long buffer

System.out.println(

"Buffer before operation: "

+ Arrays.toString(

longBuffer.array())

+ "\nPosition: "

+ longBuffer.position()

+ "\nLimit: "

+ longBuffer.limit());

// rewind the Buffer

// using rewind() method

longBuffer.rewind();

// print the longbuffer

System.out.println(

"\nBuffer after operation: "

+ Arrays.toString(

longBuffer.array())

+ "\nPosition: "

+ longBuffer.position()

+ "\nLimit: "

+ longBuffer.limit());

}

}

输出：

Buffer before operation: [10, 20, 0, 0]

Position: 2

Limit: 4

Buffer after operation: [10, 20, 0, 0]

Position: 0

Limit: 4

范例2：

// Java program to demonstrate

// rewind() method

import java.nio.*;

import java.util.*;

public class GFG {

public static void main(String[] args)

{

// defining and allocating LongBuffer

// using allocate() method

LongBuffer longBuffer

= LongBuffer.allocate(5);

// put long value in longBuffer

// using put() method

longBuffer.put(10);

longBuffer.put(20);

longBuffer.put(30);

// mark will be going to

// discarded by rewind()

longBuffer.mark();

// print the buffer

System.out.println(

"Buffer before operation: "

+ Arrays.toString(

longBuffer.array())

+ "\nPosition: "

+ longBuffer.position()

+ "\nLimit: "

+ longBuffer.limit());

// Rewind the Buffer

// using rewind() method

longBuffer.rewind();

// print the buffer

System.out.println(

"\nBuffer after operation: "

+ Arrays.toString(

longBuffer.array())

+ "\nPosition: "

+ longBuffer.position()

+ "\nLimit: "

+ longBuffer.limit());

}

}

输出：

Buffer before operation: [10, 20, 30, 0, 0]

Position: 3

Limit: 5

Buffer after operation: [10, 20, 30, 0, 0]

Position: 0

Limit: 5