Java 中的 ShortBuffer compact()方法，示例
原文:https://www . geesforgeks . org/short buffer-compact-method-in-Java-with-examples/
java.nio.ShortBuffer 类的 compact() 方法用于压缩给定的缓冲区。缓冲区的当前位置与其限制(如果有)之间的短路被复制到缓冲区的开头。也就是说，索引 p =位置()处的短路被复制到索引 0，索引 p + 1 处的短路被复制到索引 1，以此类推，直到索引极限()–1 处的短路被复制到索引 n =极限()–1–p。然后，缓冲区的位置被设置为 n+1，其极限被设置为其容量。如果定义了标记，则会将其丢弃。缓冲区的位置被设置为复制的短路数，而不是零，因此调用此方法后可以立即调用另一个相对 put 方法。
语法:
public abstract ShortBuffer compact()
返回值:该方法返回与该缓冲区内容相同的新短缓冲区。
异常:如果这个缓冲区是只读的，这个方法抛出readonlybufferenexception。
下面的程序说明了紧凑()的方法:
程序 1 :
// Java program to demonstrate
// compact() 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
// creating object of shortbuffer
// and allocating size capacity
ShortBuffer sb = ShortBuffer.allocate(capacity);
// putting the value in shortbuffer
sb.put((short)856);
sb.put((short)961);
sb.put((short)54);
// print the ShortBuffer
System.out.println("Original ShortBuffer: "
+ Arrays.toString(sb.array()));
System.out.println("Position: " + sb.position());
System.out.println("limit: " + sb.limit());
// Creating a compacted ShortBuffer of same ShortBuffer
// using compact() method
ShortBuffer shortBuffer = sb.compact();
// print the ShortBuffer
System.out.println("\nCompacted ShortBuffer: "
+ Arrays.toString(shortBuffer.array()));
System.out.println("Position: " + shortBuffer.position());
System.out.println("limit: " + shortBuffer.limit());
// putting the value in compacted shortbuffer
shortBuffer.put((short)961);
// print the ShortBuffer
System.out.println("\nUpdated Compacted ShortBuffer: "
+ Arrays.toString(shortBuffer.array()));
System.out.println("Position: " + shortBuffer.position());
System.out.println("limit: " + shortBuffer.limit());
}
}
Output:
Original ShortBuffer: [856, 961, 54, 0, 0, 0, 0, 0, 0, 0]
Position: 3
limit: 10
Compacted ShortBuffer: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
Position: 7
limit: 10
Updated Compacted ShortBuffer: [0, 0, 0, 0, 0, 0, 0, 961, 0, 0]
Position: 8
limit: 10
程序 2: 演示 ReadOnlyBufferException。
// Java program to demonstrate
// compact() 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 floatbuffer
sb.put((short)856);
sb.put((short)961);
sb.put((short)6010);
sb.rewind();
// Creating a read-only copy of ShortBuffer
// using asReadOnlyBuffer() method
ShortBuffer sb1 = sb.asReadOnlyBuffer();
// print the ReadOnlyBuffer
System.out.print("ReadOnlyBuffer ShortBuffer: ");
while (sb1.hasRemaining())
System.out.print(sb1.get() + ", ");
System.out.println("");
// print the Position of ShortBuffer sb
System.out.println("\nPosition: " + sb.position());
// print the Limit of ShortBuffer fb
System.out.println("\nlimit: " + sb.limit());
// Creating a compacted ShortBuffer of same ReadOnlyBuffer
// using compact() method
System.out.println("\nTrying to compact the ReadOnlyBuffer sb1");
ShortBuffer floatBuffer = sb1.compact();
}
catch (IllegalArgumentException e) {
System.out.println("Exception throws " + e);
}
catch (ReadOnlyBufferException e) {
System.out.println("Exception throws " + e);
}
}
}
Output:
ReadOnlyBuffer ShortBuffer: 856, 961, 6010, 0, 0, 0, 0, 0, 0, 0,
Position: 0
limit: 10
Trying to compact the ReadOnlyBuffer sb1
Exception throws java.nio.ReadOnlyBufferException
版权属于：月萌API www.moonapi.com，转载请注明出处
