Java IntBuffer clear()方法及示例
java.nio.IntBuffer 类的 clear() 方法被用来清除这个缓冲区。在清除这个缓冲区时,会做以下改变。
- 位置被设置为零
- 限制被设置为容量
- 标记被丢弃。
语法
public final IntBuffer clear()
Java
参数: 该方法不接受任何参数。
返回值: 该方法在清除IntBuffer中的所有数据后返回该实例。
下面的例子说明了clear()方法的作用。
例子 1 :
// Java program to demonstrate
// clear() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
try {
int[] iarr = { 10, 20, 30, 40 };
// creating object of IntBuffer
// and allocating size capacity
IntBuffer ib
= IntBuffer.wrap(iarr);
// try to set the position at index 2
ib.position(2);
// Set this buffer mark position
// using mark() method
ib.mark();
// try to set the position at index 4
ib.position(4);
// display position
System.out.println("position before reset: "
+ ib.position());
// try to call clear() to restore
// to the position at index 0
// by discarding the mark
ib.clear();
// display position
System.out.println("position after reset: "
+ ib.position());
}
catch (InvalidMarkException e) {
System.out.println("new position is less than "
+ "the position we "
+ "marked before ");
System.out.println("Exception throws: " + e);
}
}
}
Java
输出:
position before reset: 4
position after reset: 0
Java
例子 2 :
// Java program to demonstrate
// clear() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
int[] iarr = { 10, 20, 30, 40 };
// creating object of IntBuffer
// and allocating size capacity
IntBuffer ib = IntBuffer.wrap(iarr);
// try to set the position at index 3
ib.position(3);
// display position
System.out.println("position before clear: "
+ ib.position());
// try to call clear() to restore
// to the position at index 0
// by discarding the mark
ib.clear();
// display position
System.out.println("position after clear: "
+ ib.position());
}
}
Java
输出:
position before clear: 3
position after clear: 0
Java
参考资料: https://docs.oracle.com/javase/9/docs/api/java/nio/IntBuffer.html#rewind-