极客教程Java ByteBuffer getShort()方法及示例
getShort( )
java.nio.ByteBuffer 类的 getShort() 方法用于读取该缓冲区当前位置的下两个字节，根据当前的字节顺序将其合成为一个短值，然后将该位置增加2。
语法
public abstract short getShort()
返回值： 该方法返回缓冲区当前位置的短值。
抛出： 如果该缓冲区内剩余的字节数少于4个，该方法会抛出 BufferUnderflowException 。
下面是说明getShort()方法的例子。
例子 1 :
// Java program to demonstrate
// getShort() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the ByteBuffer
int capacity = 6;
// Creating the ByteBuffer
try {
// creating object of ByteBuffer
// and allocating size capacity
ByteBuffer bb = ByteBuffer.allocate(capacity);
// putting the short value in the bytebuffer
bb.asShortBuffer()
.put((short)1034)
.put((short)1035)
.put((short)1036);
// rewind the Bytebuffer
bb.rewind();
// print the ByteBuffer
System.out.println("Original ByteBuffer: ");
for (int i = 1; i <= capacity / 2; i++)
System.out.print(bb.getShort() + " ");
// rewind the Bytebuffer
bb.rewind();
// Reads the long at this buffer's current position
// using getShort() method
long value = bb.getShort();
// print the long value
System.out.println("\n\nByte Value: " + value);
// Reads the short at this buffer's next position
// using getShort() method
long value1 = bb.getShort();
// print the short value
System.out.print("\nNext Byte Value: " + value1);
}
catch (BufferUnderflowException e) {
System.out.println("\nException Thrown : " + e);
}
}
}
输出。
Original ByteBuffer:
1034 1035 1036
Byte Value: 1034
Next Byte Value: 1035
例子 2 :
// Java program to demonstrate
// getShort() 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 the ByteBuffer
try {
// creating object of ByteBuffer
// and allocating size capacity
ByteBuffer bb = ByteBuffer.allocate(capacity);
// putting the short value in the bytebuffer
bb.asShortBuffer()
.put((short)1034)
.put((short)1036);
// rewind the Bytebuffer
bb.rewind();
// print the ByteBuffer
System.out.println("Original ByteBuffer: ");
for (int i = 1; i <= capacity / 2; i++)
System.out.print(bb.getShort() + " ");
// rewind the Bytebuffer
bb.rewind();
// Reads the long at this buffer's current position
// using getShort() method
long value = bb.getShort();
// print the long value
System.out.println("\n\nByte Value: " + value);
// Reads the short at this buffer's next position
// using getShort() method
long value1 = bb.getShort();
// print the short value
System.out.print("\nNext Byte Value: " + value1);
// Reads the short at this buffer's next position
// using getShort() method
long value2 = bb.getShort();
}
catch (BufferUnderflowException e) {
System.out.println("\nthere are fewer than"
+ " two bytes remaining in this buffer");
System.out.println("Exception Thrown : " + e);
}
}
}
输出。
Original ByteBuffer:
1034 1036
Byte Value: 1034
Next Byte Value: 1036
there are fewer than two bytes remaining in this buffer
Exception Thrown : java.nio.BufferUnderflowException
参考资料: https://docs.oracle.com/javase/9/docs/api/java/nio/ByteBuffer.html#getShort-
getLong(int index)
ByteBuffer 的 getLong(int index) 方法用于在给定的索引处读取四个字节，根据当前的字节顺序将它们合成为一个浮点数。
语法
public abstract long getLong(int index)
参数： 该方法以index（将被读取的字节的索引）为参数。
返回值： 该方法返回给定索引处的长值。
异常： 该方法抛出 IndexOutOfBoundsException。 如果索引为负数或不小于缓冲区的限制，就会抛出这个异常。
下面是一些例子来说明getLong(int index)方法。
例子 1 :
// Java program to demonstrate
// getShort() 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 the ByteBuffer
try {
// creating object of ByteBuffer
// and allocating size capacity
ByteBuffer bb = ByteBuffer.allocate(capacity);
// putting the short value in the bytebuffer
bb.asShortBuffer()
.put((short)1034)
.put((short)1036);
// rewind the Bytebuffer
bb.rewind();
// print the ByteBuffer
System.out.println("Original ByteBuffer: ");
for (int i = 1; i <= capacity / 2; i++)
System.out.print(bb.getShort() + " ");
// rewind the Bytebuffer
bb.rewind();
// Reads the long at this buffer's current position
// using getShort() method
long value = bb.getShort(0);
// print the long value
System.out.println("\n\nByte Value: " + value);
// Reads the short at this buffer's next position
// using getShort() method
long value1 = bb.getShort(2);
// print the short value
System.out.print("\nNext Byte Value: " + value1);
}
catch (IndexOutOfBoundsException e) {
System.out.println("\nindex is negative or "
+ "smaller than the buffer's limit, "
+ " minus seven");
System.out.println("Exception Thrown : " + e);
}
}
}
输出。
Original ByteBuffer:
1034 1036
Byte Value: 1034
Next Byte Value: 1036
例子 2 :
// Java program to demonstrate
// getShort() 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 the ByteBuffer
try {
// creating object of ByteBuffer
// and allocating size capacity
ByteBuffer bb = ByteBuffer.allocate(capacity);
// putting the short value in the bytebuffer
bb.asShortBuffer()
.put((short)1034)
.put((short)1036);
// rewind the Bytebuffer
bb.rewind();
// print the ByteBuffer
System.out.println("Original ByteBuffer: ");
for (int i = 1; i <= capacity / 2; i++)
System.out.print(bb.getShort() + " ");
// rewind the Bytebuffer
bb.rewind();
// Reads the long at this buffer's current position
// using getShort() method
long value = bb.getShort(0);
// print the long value
System.out.println("\n\nByte Value: " + value);
// Reads the short at this buffer's next position
// using getShort() method
long value1 = bb.getShort(3);
// print the short value
System.out.print("\nNext Byte Value: " + value1);
}
catch (IndexOutOfBoundsException e) {
System.out.println("\nindex is negative or smaller "
+ "than the buffer's limit, "
+ "minus one");
System.out.println("Exception Thrown : " + e);
}
}
}
输出。
Original ByteBuffer:
1034 1036
Byte Value: 1034
index is negative or smaller than the buffer's limit, minus one
Exception Thrown : java.lang.IndexOutOfBoundsException
参考资料: https://docs.oracle.com/javase/9/docs/api/java/nio/ByteBuffer.html#getShort-int-