Java 中的 CharBuffer clear()方法，示例
原文:https://www . geesforgeks . org/char buffer-clear-methods-in-Java-with-examples/
Java . nio . charbuffer类的 clear() 方法用于清除该缓冲区。位置设置为零，限制设置为容量，标记被丢弃。在使用一系列通道读取或放置操作来填充此缓冲区之前，请调用此方法。
例如:
// Prepare buffer for reading
buf.clear();
// Read data
in.read(buf);
这种方法实际上并不擦除缓冲区中的数据，但它的命名就好像它擦除了数据一样，因为它最常用于这种情况。
语法:
public final CharBuffer clear()
返回值:这个方法返回这个缓冲区。
以下是说明 clear()方法的示例:
示例 1:
// Java program to demonstrate
// clear() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
try {
char[] carr = { 'a', 'b', 'c', 'd' };
// creating object of CharBuffer
// and allocating size capacity
CharBuffer cb = CharBuffer.wrap(carr);
// try to set the position at index 2
cb.position(2);
// Set this buffer mark position
// using mark() method
cb.mark();
// try to set the position at index 4
cb.position(4);
// display position
System.out.println("position before reset: "
+ cb.position());
// try to call clear() to restore
// to the position at index 0
// by discarding the mark
cb.clear();
// display position
System.out.println("position after reset: "
+ cb.position());
}
catch (InvalidMarkException e) {
System.out.println("new position is less than "
+ "the position we "
+ "marked before ");
System.out.println("Exception throws: " + e);
}
}
}
输出:
position before reset: 4
position after reset: 0
示例 2:
// Java program to demonstrate
// clear() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
char[] carr = { '.', '<', '@', 'a' };
// creating object of CharBuffer
// and allocating size capacity
CharBuffer cb = CharBuffer.wrap(carr);
// try to set the position at index 2
cb.position(3);
// display position
System.out.println("position before clear: "
+ cb.position());
// try to call clear() to restore
// to the position at index 0
// by discarding the mark
cb.clear();
// display position
System.out.println("position after clear: "
+ cb.position());
}
}
输出:
position before clear: 3
position after clear: 0
参考:https://docs . Oracle . com/javase/9/docs/API/Java/nio/charbuffer . html # clear–
版权属于：月萌API www.moonapi.com，转载请注明出处
