The **`order()` method** of the `DoubleBuffer` class in Java retrieves a buffer’s byte order.

The process is illustrated below.

To use the `order()` method, you will need to import the `DoubleBuffer` class into your program, as shown below.

```Java
import java.nio.DoubleBuffer
```

The prototype of this method is shown below.

```Java
public final ByteOrder order()
```

#   
#  Parameters

The `order()` method does not accept any parameters.

#   
## Return value

The `order()` method returns the buffer’s byte order.

The byte order of a `DoubleBuffer` object can be one of the following:

* If the buffer is created by allocation or by wrapping an existing `double` array, then the byte order reflects the [native order](https://docs.oracle.com/javase/7/docs/api/java/nio/ByteOrder.html#nativeOrder()) of the underlying hardware.

* If the buffer is created as a view of a `ByteBuffer`, then the byte order reflects the byte order of the `ByteBuffer` object when the `DoubleBuffer` view was created.

##  
## Example

The code below shows how the `order()` method can be used in Java.

import java.nio.*;
import java.util.*;

class orderMethod {
  public static void main(String[] args) {

    // initialize buffer instances
    ByteBuffer byteBuffer = ByteBuffer.allocate(5);
    DoubleBuffer firstBuffer = DoubleBuffer.allocate(5);
    DoubleBuffer secondBuffer = byteBuffer.asDoubleBuffer();

    // Retrieve byte order of buffers
    ByteOrder currentByteOrder = firstBuffer.order();
    System.out.println("The byte order of firstBuffer is: " + currentByteOrder);
    
    currentByteOrder = secondBuffer.order();
    System.out.println("The byte order of secondBuffer is: " + currentByteOrder);

  }
}

#   
## Explanation

First, two `DoubleBuffer` objects are initialized: `firstBuffer` and `secondBuffer`. **`firstBuffer`** is created through the `allocate()` method, whereas **`secondBuffer`** is a view of a `ByteBuffer` object created through the `asDoubleBuffer()` method.

Since `firstBuffer` was allocated directly, the `order()` method in line $13$ returns the native order of the underlying hardware, i.e., `LITTLE_ENDIAN`.

On the other hand, `secondBuffer` is a view of a `ByteBuffer` object, so the `order()` method in line $16$ returns the byte order of the `ByteBuffer` object at the moment when the `DoubleBuffer` view was created, i.e., `BIG_ENDIAN`.

What is the DoubleBuffer order() method in Java?

The `order()` method in Java’s DoubleBuffer class retrieves the buffer’s byte order, reflecting either hardware's native order or ByteBuffer's byte order.