Java IntBuffer asReadOnlyBuffer()方法
java.nio.IntBuffer类的asReadOnlyBuffer()方法是用来创建一个新的、只读的int缓冲区，其内容是这个缓冲区的。新的缓冲区是这个缓冲区的复制品。因此，对这个缓冲区的内容所做的改变将在新的缓冲区中可见。
由于新的缓冲区是只读的，因此不允许对其内容进行任何修改。两个缓冲区的位置、极限和标记值将是独立的。新缓冲区的容量、极限、位置和标记值将与这个缓冲区的相同。如果这个缓冲区本身是只读的，那么这个方法的行为与复制方法完全相同。
语法:
public abstract IntBuffer asReadOnlyBuffer()
返回值： 该方法返回新的、只读的int缓冲区，其内容与此缓冲区的内容相同。
下面是说明asReadOnlyBuffer()方法的例子。
例子 1 :
// Java program to demonstrate// asReadOnlyBuffer() method import java.nio.*;import java.util.*; public class GFG { public static void main(String[] args) { // Declaring the capacity of the IntBuffer int capacity = 10; // Creating the IntBuffer try { // creating object of Intbuffer // and allocating size capacity IntBuffer ib = IntBuffer.allocate(capacity); // putting the value in Intbuffer ib.put(8); ib.put(2, 9); ib.rewind(); // print the IntBuffer System.out.println("Original IntBuffer: " + Arrays.toString(ib.array())); // Creating a read-only copy of IntBuffer // using asReadOnlyBuffer() method IntBuffer IntBuffer = ib.asReadOnlyBuffer(); // print the IntBuffer System.out.print("\nReadOnlyBuffer IntBuffer: "); while (IntBuffer.hasRemaining()) System.out.print(IntBuffer.get() + ", "); } catch (IllegalArgumentException e) { System.out.println("IllegalArgumentException catched"); } catch (ReadOnlyBufferException e) { System.out.println("ReadOnlyBufferException catched"); } }}
输出:
Original IntBuffer: [8, 0, 9, 0, 0, 0, 0, 0, 0, 0]ReadOnlyBuffer IntBuffer: 8, 0, 9, 0, 0, 0, 0, 0, 0, 0,
例子 2 :
// Java program to demonstrate// asReadOnlyBuffer() method import java.nio.*;import java.util.*; public class GFG { public static void main(String[] args) throws Exception { // Declaring the capacity of the ib int capacity1 = 10; // Declaring the capacity of the ib1 int capacity2 = 5; // Creating the IntBuffer try { // creating object of Intbuffer ib // and allocating size capacity IntBuffer ib = IntBuffer.allocate(capacity1); // putting the value in ib ib.put(8); ib.put(2, 9); ib.rewind(); // print the IntBuffer System.out.println("IntBuffer ib: " + Arrays.toString(ib.array())); // ib1 // creating object of Intbuffer ib1 // and allocating size capacity IntBuffer ib1 = IntBuffer.allocate(capacity2); // putting the value in ib1 ib1.put(1, 4); ib1.put(2, 6); ib1.rewind(); // print the IntBuffer System.out.println("\nIntBuffer ib1: " + Arrays.toString(ib1.array())); // Creating a read-only copy of IntBuffer // using asReadOnlyBuffer() method IntBuffer readOnlyib = ib.asReadOnlyBuffer(); // print the IntBuffer System.out.print("\nReadOnlyBuffer IntBuffer: "); while (readOnlyib.hasRemaining()) System.out.print(readOnlyib.get() + ", "); // try to change readOnlyib System.out.println("\n\nTrying to get the array" + " from ReadOnlyib for editing"); int[] ibarr = readOnlyib.array(); } catch (IllegalArgumentException e) { System.out.println("IllegalArgumentException catched"); } catch (ReadOnlyBufferException e) { System.out.println("Exception thrown: " + e); } }}输出:
IntBuffer ib: [8, 0, 9, 0, 0, 0, 0, 0, 0, 0]IntBuffer ib1: [0, 4, 6, 0, 0]ReadOnlyBuffer IntBuffer: 8, 0, 9, 0, 0, 0, 0, 0, 0, 0, Trying to get the array from ReadOnlyib for editingException thrown: java.nio.ReadOnlyBufferException
