Java中的DoubleBuffer equals()方法及示例

Java.nio.DoubleBuffer r Class 的equals()方法用于检查给定缓冲区是否等于另一个对象。

当且仅当，两个双缓冲区相等

• 它们具有相同的元素类型，
• 它们具有相同数量的剩余元素，并且
• 剩余元素的两个序列，独立于它们的起始位置考虑，是逐点的
  平等的。

如果 (a == b) || 此方法认为两个双元素 a 和 b 相等(Double.isNaN(a) && Double.isNaN(b))。与 Double.equals(Object) 不同，值 -0.0 和 +0.0 被认为是相等的。

双缓冲区不等于任何其他类型的对象。

句法：

public boolean equals(Object ob)

参数：此方法将ob （此缓冲区要与之比较的对象）作为参数。

返回值：当且仅当此缓冲区等于给定对象时，此方法返回true 。

以下是说明 equals() 方法的示例：

示例 1：

// Java program to demonstrate
// equals() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the DoubleBuffer 1
        int capacity1 = 10;
  
        // Declaring the capacity of the  DoubleBuffer 2
        int capacity2 = 10;
  
        // Creating the DoubleBuffer
        try {
  
            // creating object of Doublebuffer 1
            // and allocating size capacity
            DoubleBuffer db1 = DoubleBuffer.allocate(capacity1);
  
            // creating object of Doublebuffer 2
            // and allocating size capacity
            DoubleBuffer db2 = DoubleBuffer.allocate(capacity2);
  
            // putting the value in Doublebuffer 1
            db1.put(8.56F);
            db1.put(2, 9.61F);
            db1.rewind();
  
            // putting the value in Doublebuffer 2
            db2.put(8.56F);
            db2.put(2, 9.61F);
            db2.rewind();
  
            // print the DoubleBuffer 1
            System.out.println(" DoubleBuffer 1:  "
                               + Arrays.toString(db1.array()));
  
            // print the DoubleBuffer 2
            System.out.println(" DoubleBuffer 2:  "
                               + Arrays.toString(db2.array()));
  
            // checking the equality of both DoubleBuffer
            boolean dbb = db1.equals(db2);
  
            // checking if else condition
            if (dbb)
                System.out.println("both are equal");
            else
                System.out.println("both are not equal");
        }
  
        catch (IllegalArgumentException e) {
            System.out.println("IllegalArgumentException catched");
        }
  
        catch (ReadOnlyBufferException e) {
            System.out.println("ReadOnlyBufferException catched");
        }
    }
}

输出：

DoubleBuffer 1:  [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
 DoubleBuffer 2:  [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
both are equal

示例 1：

// Java program to demonstrate
// equals() method
  
import java.nio.*;
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // Declaring the capacity of the DoubleBuffer 1
        int capacity1 = 10;
  
        // Declaring the capacity of the  DoubleBuffer 2
        int capacity2 = 5;
  
        // Creating the DoubleBuffer
        try {
  
            // creating object of Doublebuffer 1
            // and allocating size capacity
            DoubleBuffer db1 = DoubleBuffer.allocate(capacity1);
  
            // creating object of Doublebuffer 2
            // and allocating size capacity
            DoubleBuffer db2 = DoubleBuffer.allocate(capacity2);
  
            // putting the value in Doublebuffer 1
            db1.put(8.56F);
            db1.put(2, 9.61F);
            db1.rewind();
  
            // putting the value in Doublebuffer 2
            db2.put(8.56F);
            db2.put(2, 9.61F);
            db2.rewind();
  
            // print the DoubleBuffer 1
            System.out.println(" DoubleBuffer 1:  "
                               + Arrays.toString(db1.array()));
  
            // print the DoubleBuffer 2
            System.out.println(" DoubleBuffer 2:  "
                               + Arrays.toString(db2.array()));
  
            // checking the equality of both DoubleBuffer
            boolean dbb = db1.equals(db2);
  
            // checking if else condition
            if (dbb)
                System.out.println("both are equal");
            else
                System.out.println("both are not equal");
        }
        catch (IllegalArgumentException e) {
  
            System.out.println("IllegalArgumentException catched");
        }
  
        catch (ReadOnlyBufferException e) {
  
            System.out.println("ReadOnlyBufferException catched");
        }
    }
}

输出：

DoubleBuffer 1:  [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
 DoubleBuffer 2:  [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0]
both are not equal