Java中的 ByteBuffer toString() 方法及示例

ByteBuffer 类的toString()方法是用于返回表示 ByteBuffer 对象所包含数据的字符串的内置方法。创建并初始化一个新的 String 对象，以从该 ByteBuffer 对象中获取字符序列，然后由 toString() 返回 String。 Object 包含的此序列的后续更改不会影响 String 的内容。
句法：

public abstract String toString()

返回值：该方法返回表示 ByteBuffer 对象包含的数据的字符串。
下面的程序说明了 ByteBuffer.toString() 方法：
示例 1：

Java

// Java program to demonstrate
// toString() method
 
import java.nio.*;
import java.util.*;
 
public class GFG {
 
    public static void main(String[] args)
    {
 
        // Declaring the capacity of the ByteBuffer
        int capacity = 5;
 
        // creating object of ByteBuffer
        // and allocating size capacity
        ByteBuffer bb1 = ByteBuffer.allocate(capacity);
 
        // putting the value in ByteBuffer
        bb1.put((byte)10);
        bb1.put((byte)20);
 
        // print the ByteBuffer
        System.out.println("Original ByteBuffer: "
                           + Arrays.toString(bb1.array()));
 
        // Creating a shared subsequence buffer of given ByteBuffer
        // using toString() method
        String value = bb1.toString();
 
        // print the ByteBuffer
        System.out.println("\nstring representation of ByteBuffer:  "
                           + value);
    }
}

输出：

Original ByteBuffer: [10, 20, 0, 0, 0]

string representation of ByteBuffer:  java.nio.HeapByteBuffer[pos=2 lim=5 cap=5]

示例 2：

Java

// Java program to demonstrate
// toString() method
 
import java.nio.*;
import java.util.*;
 
public class GFG {
 
    public static void main(String[] args)
    {
 
        // Declaring the capacity of the ByteBuffer
        int capacity = 4;
 
        // creating object of ByteBuffer
        // and allocating size capacity
        ByteBuffer bb1 = ByteBuffer.allocate(capacity);
 
        // putting the value in ByteBuffer
        bb1.put((byte)10)
            .put((byte)20)
            .put((byte)30)
            .put((byte)40);
 
        // print the ByteBuffer
        System.out.println("Original ByteBuffer: "
                           + Arrays.toString(bb1.array()));
 
        // Creating a shared subsequence buffer of given ByteBuffer
        // using toString() method
        String value = bb1.toString();
 
        // print the ByteBuffer
        System.out.println("\nstring representation of ByteBuffer:  "
                           + value);
    }
}

输出：

Original ByteBuffer: [10, 20, 30, 40]

string representation of ByteBuffer:  java.nio.HeapByteBuffer[pos=4 lim=4 cap=4]

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