Java中的 ShortBuffer asReadOnlyBuffer() 方法及示例
Java.nio.ShortBuffer类的asReadOnlyBuffer()方法用于使用此缓冲区的内容创建一个新的只读短缓冲区。新缓冲区是此缓冲区的副本。因此,对此缓冲区内容所做的更改将在新缓冲区中可见。
由于新缓冲区是只读的,因此不允许对其内容进行任何修改。两个缓冲区的位置、限制和标记值将是独立的。新缓冲区的容量、限制、位置和标记值将与此缓冲区的相同。如果此缓冲区本身是只读的,则此方法的行为方式与复制方法完全相同。
语法:
public abstract ShortBuffer asReadOnlyBuffer()
返回值:此方法返回与此缓冲区内容相同的新的只读短缓冲区。
下面是说明asReadOnlyBuffer()方法的示例:
程序 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 ShortBuffer
int capacity = 10;
// Creating the ShortBuffer
try {
// creating object of shortbuffer
// and allocating size capacity
ShortBuffer sb = ShortBuffer.allocate(capacity);
// putting the value in shortbuffer
sb.put((short)856);
sb.put(2, (short)961);
sb.rewind();
// print the ShortBuffer
System.out.println("Original ShortBuffer: "
+ Arrays.toString(sb.array()));
// Creating a read-only copy of ShortBuffer
// using asReadOnlyBuffer() method
ShortBuffer shortBuffer = sb.asReadOnlyBuffer();
// print the ShortBuffer
System.out.print("\nReadOnlyBuffer ShortBuffer: ");
while (shortBuffer.hasRemaining())
System.out.print(shortBuffer.get() + ", ");
}
catch (IllegalArgumentException e) {
System.out.println("IllegalArgumentException catched");
}
catch (ReadOnlyBufferException e) {
System.out.println("ReadOnlyBufferException catched");
}
}
}
输出:
Original ShortBuffer: [856, 0, 961, 0, 0, 0, 0, 0, 0, 0]
ReadOnlyBuffer ShortBuffer: 856, 0, 961, 0, 0, 0, 0, 0, 0, 0,
方案二:
// 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 sb
int capacity1 = 10;
// Declaring the capacity of the sb1
int capacity2 = 5;
// Creating the ShortBuffer
try {
//
// sb
//
// creating object of shortbuffer sb
// and allocating size capacity
ShortBuffer sb = ShortBuffer.allocate(capacity1);
// putting the value in sb
sb.put((short)856);
sb.put(2, (short)961);
sb.rewind();
// print the ShortBuffer
System.out.println("ShortBuffer sb: "
+ Arrays.toString(sb.array()));
//
// sb1
//
// creating object of shortbuffer sb1
// and allocating size capacity
ShortBuffer sb1 = ShortBuffer.allocate(capacity2);
// putting the value in sb1
sb1.put(1, (short)456);
sb1.put(2, (short)645);
sb1.rewind();
// print the ShortBuffer
System.out.println("\nShortBuffer sb1: "
+ Arrays.toString(sb1.array()));
// Creating a read-only copy of ShortBuffer
// using asReadOnlyBuffer() method
ShortBuffer readOnlySb = sb.asReadOnlyBuffer();
// print the ShortBuffer
System.out.print("\nReadOnlyBuffer FloatBuffer: ");
while (readOnlySb.hasRemaining())
System.out.print(readOnlySb.get() + ", ");
// try to change readOnlySb
System.out.println("\n\nTrying to get the array"
+ " from ReadOnlyFb for editing");
short[] sbarr = readOnlySb.array();
}
catch (IllegalArgumentException e) {
System.out.println("IllegalArgumentException catched");
}
catch (ReadOnlyBufferException e) {
System.out.println("Exception thrown: " + e);
}
}
}
输出:
ShortBuffer sb: [856, 0, 961, 0, 0, 0, 0, 0, 0, 0]
ShortBuffer sb1: [0, 456, 645, 0, 0]
ReadOnlyBuffer FloatBuffer: 856, 0, 961, 0, 0, 0, 0, 0, 0, 0,
Trying to get the array from ReadOnlyFb for editing
Exception thrown: java.nio.ReadOnlyBufferException