NIO-ByteBuffer与字符串互相转换

字符串转换为ByteBuffer

//1、字符串转换为ByteBuffer
ByteBuffer buffer = ByteBuffer.allocate(16);
buffer.put("hello".getBytes());
buffer.flip(); //切换到读模式
System.out.println((char) buffer.get(1));

//2、charset 会自动切换到读模式
ByteBuffer buffer1 = StandardCharsets.UTF_8.encode("hello wor");
System.out.println((char)buffer1.get(8));

//3、wrap 会自动切换到读模式
ByteBuffer buffer2 = ByteBuffer.wrap("helll9l".getBytes());
System.out.println((char)buffer2.get(5));

ByteBuffer转换为字符串

//4、ByteBuffer转换为字符串
String s = StandardCharsets.UTF_8.decode(buffer).toString();
System.out.println(s);