Java DoubleBuffer get()方法及实例

java.nio.DoubleBuffer类的 get() 方法用于读取指定缓冲区当前位置的双倍数，然后递增该位置。

语法

public abstract double get()

返回值： 该方法返回缓冲区当前位置的双倍值。

异常： 该方法抛出 BufferUnderflowException ，如果缓冲区的当前位置不小于其极限值，则抛出此异常。

下面是说明get()方法的例子。

例子 1 :

// Java program to demonstrate// get() method  import java.nio.*;import java.util.*;  public class GFG {      public static void main(String[] args)    {          // Declaring the capacity of the FloatBuffer        int capacity = 5;          // Creating the FloatBuffer        try {              // creating object of floatbuffer            // and allocating size capacity            DoubleBuffer fb                = DoubleBuffer.allocate(capacity);              // putting the value in Doublebuffer            fb.put(8.56D);            fb.put(9.61D);            fb.put(1.24D);            fb.rewind();              // print the DoubleBuffer            System.out.println("Original DoubleBuffer:  "                               + Arrays.toString(fb.array()));              // Reads the double at this buffer's current position            // using get() method            double value = fb.get();              // print the double value            System.out.println("\nDouble Value: "                               + value);              // Reads the  double at this buffer's next position            // using get() method            double value1 = fb.get();              // print the double value            System.out.print("\nNext double Value: " + value1);        }          catch (IllegalArgumentException e) {              System.out.println("\nIllegalArgumentException catched");        }          catch (ReadOnlyBufferException e) {              System.out.println("\nReadOnlyBufferException catched");        }          catch (BufferUnderflowException e) {              System.out.println("\nException throws: " + e);        }    }}

输出:

Original DoubleBuffer:  [8.56, 9.61, 1.24, 0.0, 0.0]Double Value: 8.56Next double Value: 9.61

例子 2 :

// Java program to demonstrate// get() method  import java.nio.*;import java.util.*;  public class GFG {      public static void main(String[] args)    {          // Declaring the capacity of the DoubleBuffer        int capacity = 3;          // Creating the DoubleBuffer        try {              // creating object of Doublebuffer            // and allocating size capacity            DoubleBuffer fb = DoubleBuffer.allocate(capacity);              // putting the value in Doublebuffer            fb.put(8.56F);            fb.put(9.61F);              // print the DoubleBuffer            System.out.println("Original DoubleBuffer:  "                               + Arrays.toString(fb.array()));              // Reads the Double at this buffer's current position            // using get() method            Double value = fb.get();              // print the Double value            System.out.println("\nDouble Value: " + value);              // Reads the  Double at this buffer's next position            // using get() method            System.out.print("\nsince the buffer current"                             + " position is incremented");            System.out.print(" to greater than its limit ");              Double value1 = fb.get();              // print the Double value            System.out.print("\nNext Double Value: " + value1);        }          catch (IllegalArgumentException e) {              System.out.println("\nIllegalArgumentException catched");        }          catch (ReadOnlyBufferException e) {              System.out.println("\nReadOnlyBufferException catched");        }          catch (BufferUnderflowException e) {              System.out.println("\nException throws: " + e);        }    }}

输出:

Original DoubleBuffer:  [8.5600004196167, 9.609999656677246, 0.0]Double Value: 0.0since the buffer current position is incremented to greater than its limit Exception throws: java.nio.BufferUnderflowException

参考资料: https://docs.oracle.com/javase/9/docs/api/java/nio/DoubleBuffer.html#get-