Java中的 DoubleBuffer allocate() 方法示例
Java.nio.DoubleBuffer类的allocate()方法用于在现有缓冲区旁边分配一个新的双缓冲区。新缓冲区的位置将为零。它的极限将是它的容量。它的标记将是未定义的。并且它的每个元素都将被初始化为零。它将有一个支持数组,并且它的数组偏移量为零。
句法:
public static DoubleBuffer allocate(int capacity)
参数:此方法将新缓冲区的容量以双精度形式作为参数。
返回值:此方法返回新的双缓冲区。
异常:如果容量为负整数,此方法将引发IllegalArgumentException 。
下面的程序说明了 allocate() 方法:
示例 1:
Java
// Java program to demonstrate
// allocate() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the DoubleBuffer
int capacity = 10;
// Creating the DoubleBuffer
// creating object of Doublebuffer
// and allocating size capacity
DoubleBuffer db = DoubleBuffer.allocate(capacity);
// putting the value in Doublebuffer
db.put(8.56F);
db.put(2, 9.61F);
System.out.println("DoubleBuffer: "
+ Arrays.toString(db.array()));
}
}
Java
// Java program to demonstrate
// allocate() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the DoubleBuffer
// by negative integer
int capacity = -10;
// Creating the DoubleBuffer
try {
// creating object of Doublebuffer
// and allocating size with negative integer
System.out.println("Trying to allocate a negative integer");
DoubleBuffer db = DoubleBuffer.allocate(capacity);
}
catch (IllegalArgumentException e) {
System.out.println("Exception thrown: " + e);
}
}
}
输出:
DoubleBuffer: [8.5600004196167, 0.0, 9.609999656677246, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
示例 2:演示 IllegalArgumentException
Java
// Java program to demonstrate
// allocate() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the DoubleBuffer
// by negative integer
int capacity = -10;
// Creating the DoubleBuffer
try {
// creating object of Doublebuffer
// and allocating size with negative integer
System.out.println("Trying to allocate a negative integer");
DoubleBuffer db = DoubleBuffer.allocate(capacity);
}
catch (IllegalArgumentException e) {
System.out.println("Exception thrown: " + e);
}
}
}
输出
Trying to allocate a negative integer
Exception thrown: java.lang.IllegalArgumentException: capacity < 0: (-10 < 0)