Java Buffer capacity()方法及示例

来源：这里教程网时间：2026-02-17 20:37:14 作者：

Java Buffer capacity()方法及示例

java.nio.Buffer类 的 capacity() 方法是用来返回这个缓冲区的容量。

语法

public final int capacity()

返回值： 这个缓冲区的容量

下面是说明 capacity() 方法的例子。

例子 1 :

// Java program to demonstrate// capacity() method  import java.nio.*;import java.util.*;  public class GFG {      public static void main(String[] args)    {        // creating object of ByteBuffer        // and allocating size capacity        ByteBuffer bb = ByteBuffer.allocate(7);          // putting the int to byte typecast        // value in ByteBuffer        bb.put((byte)20);        bb.put((byte)30);        bb.put((byte)40);        bb.put((byte)50);          // Typecasting ByteBuffer into Buffer        Buffer bb1 = (Buffer)bb;          // getting capacity of Buffer        // using capacity() method        int cap = bb1.capacity();          // display the result        System.out.println("capacity is: "                           + cap);    }}

输出:

capacity is: 7

例子 2 :

// Java program to demonstrate// capacity() method  import java.nio.*;import java.util.*;  public class GFG {      public static void main(String[] args)    {        // Declaring and initializing byte array        byte[] byt = { (byte)20, (byte)30,                       (byte)40, (byte)50,                       (byte)60 };          // creating object of ByteBuffer        // and allocating size capacity        ByteBuffer bb = ByteBuffer.wrap(byt);          // Typecasting ByteBuffer into Buffer        Buffer bb1 = (Buffer)bb;          // getting capacity of Buffer        // using capacity() method        int cap = bb1.capacity();          // display the result        System.out.println("capacity is: "                           + cap);    }}

输出: