Java Buffer hasRemaining()方法及示例

java.nio.Buffer 类的 hasRemaining() 方法是用来告诉人们在当前位置和极限之间是否有任何元素。

语法

public final boolean hasRemaining()

返回： 当且仅当这个缓冲区中至少有一个元素剩余时，该方法将返回 true 。下面是说明 hasRemaining() 方法的例子。

例1 :

// Java program to demonstrate// hasRemaining() method import java.nio.*;import java.util.*; public class GFG {    public static void main(String[] args)    {         // Declaring the capacity of the ByteBuffer        int capacity = 10;         // creating object of bytebuffer        // and allocating size capacity        ByteBuffer bb = ByteBuffer.allocate(capacity);         // putting the value in bytebuffer        bb.put((byte)10);        bb.put((byte)20);        bb.rewind();         // Typecast bytebuffer to Buffer        Buffer buffer = (Buffer)bb;         // checking if, there is at least one element        // remaining in this buffer.        boolean isRemain = buffer.hasRemaining();         // checking if else condition        if (isRemain)            System.out.println("there is at least one "                               + "element remaining "                               + "in this buffer");        else            System.out.println("there is no "                               + "element remaining "                               + "in this buffer");    }}

输出

there is at least one element remaining in this buffer

例2 :

// Java program to demonstrate// hasRemaining() method import java.nio.*;import java.util.*; public class GFG {    public static void main(String[] args)    {         // Declaring the capacity of the ByteBuffer        int capacity = 0;         // creating object of bytebuffer        // and allocating size capacity        ByteBuffer bb = ByteBuffer.allocate(capacity);         // Typecast bytebuffer to Buffer        Buffer buffer = (Buffer)bb;         // checking buffer is backed by array or not        boolean isRemain = buffer.hasRemaining();         // checking if else condition        if (isRemain)            System.out.println("there is at least one "                               + "element remaining"                               + " in this buffer");        else            System.out.println("there is no "                               + "element remaining"                               + " in this buffer");    }}

输出

there is no element remaining in this buffer