import java.nio.CharBuffer;

public class BufferFlipCompact {
    public static void main(String[] args) {
        // 创建一个容量为8的CharBuffer
        CharBuffer buffer = CharBuffer.allocate(8);
        System.out.println("初始状态:");
        printBufferStatus(buffer);
        
        // 写入字符串"Hello"
        buffer.put("Hello");
        System.out.println("\n写入'Hello'后:");
        printBufferStatus(buffer);
        
        // 翻转缓冲区准备读取
        buffer.flip();
        System.out.println("\n翻转缓冲区后(flip):");
        printBufferStatus(buffer);
        
        // 读取前3个字符('H', 'e', 'l')
        System.out.println("\n读取前3个字符:");
        for (int i = 0; i < 3; i++) {
            char c = buffer.get();
            System.out.print(c + " ");
        }
        System.out.println();
        
        System.out.println("\n读取3个字符后:");
        printBufferStatus(buffer);
        
        // 压缩缓冲区
        buffer.compact();
        System.out.println("\n压缩缓冲区后(compact):");
        printBufferStatus(buffer);
        
        // 再写入"World"
        buffer.put("World");
        System.out.println("\n写入'World'后:");
        printBufferStatus(buffer);
        
        // 翻转并打印最终缓冲区内容
        buffer.flip();
        System.out.println("\n最终缓冲区内容:");
        while (buffer.hasRemaining()) {
            System.out.print(buffer.get());
        }
        System.out.println();
        
        // 显示完整的缓冲区内容（包括未读取的部分）
        buffer.rewind(); // 回到开始位置
        System.out.println("\n完整缓冲区内容:");
        while (buffer.hasRemaining()) {
            System.out.print(buffer.get());
        }
        System.out.println();
    }
    
    // 打印缓冲区状态
    private static void printBufferStatus(CharBuffer buffer) {
        System.out.println("Position: " + buffer.position() + 
                          ", Limit: " + buffer.limit() + 
                          ", Capacity: " + buffer.capacity() +
                          ", Remaining: " + buffer.remaining());
    }
}