有一本小书，叫<java nio>， 2002年的中文版PDF。
可以看看，尽管是一本历史感很强的书，
讲解还是很细致的。
由此进深入nio2的话，
那java io的秘密，
就全部清晰了。
package com.ronsoft.books.nio.buffers;
import java.nio.CharBuffer;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
public class BufferFillDrain {
public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
CharBuffer buffer = CharBuffer.allocate(100);
while (fillBuffer(buffer)) {
buffer.flip();
drainBuffer(buffer);
buffer.clear();
}
ByteBuffer byteBuffer = ByteBuffer.allocate(7).order(ByteOrder.BIG_ENDIAN);
CharBuffer charBuffer = byteBuffer.asCharBuffer();
byteBuffer.put(0, (byte)0);
byteBuffer.put(1, (byte)'H');
byteBuffer.put(2, (byte)0);
byteBuffer.put(3, (byte)'i');
byteBuffer.put(4, (byte)0);
byteBuffer.put(5, (byte)'!');
byteBuffer.put(6, (byte)0);
println(byteBuffer);
println(charBuffer);
}
private static void drainBuffer(CharBuffer buffer) {
while (buffer.hasRemaining()) {
System.out.print(buffer.get());
}
System.out.println("");
}
private static boolean fillBuffer(CharBuffer buffer) {
if (index >= strings.length) {
return (false);
}
String string = strings[index++];
for (int i = 0; i < string.length(); i++) {
buffer.put(string.charAt(i));
}
return (true);
}
private static int index = 0;
private static String []strings = {
"A random string value",
"The product of an infinite number of monkeys",
"Hey hey we're the Monkees",
"Opening act for the Monkees: Jimi Hendrix",
"'Scuse me while I kill this fly",
"Help Me! Help Me!",
};
private static void println(Buffer buffer) {
System.out.println("post=" + buffer.position()
+ ", limit=" + buffer.limit()
+ ", capacity=" + buffer.capacity()
+ ": '" + buffer.toString() + "'");
}
}
输出如下：
A random string value
The product of an infinite number of monkeys
Hey hey we're the Monkees
Opening act for the Monkees: Jimi Hendrix
'Scuse me while I kill this fly
Help Me! Help Me!
post=0, limit=7, capacity=7: 'java.nio.HeapByteBuffer[pos=0 lim=7 cap=7]'
post=0, limit=3, capacity=3: 'Hi!'
