處理IO時，如何定義緩沖區(qū)大?。?/h1>

public static int KB = 1024;
public static int MB = 1024 * KB;

private static final int CAPACITY_SMALL  =   4  * KB;
private static final int CAPACITY_MEDIUM = 128  * KB;
private static final int CAPACITY_LARGE  = 1024 * KB;

//package scope (default) - so they can be accessed from unit tests.
byte[]  smallMessageBuffer  = new byte[1024 *   4 * KB];   //1024 x   4KB messages =  4MB.
byte[]  mediumMessageBuffer = new byte[128  * 128 * KB];   // 128 x 128KB messages = 16MB.
byte[]  largeMessageBuffer  = new byte[16   *   1 * MB];   //  16 *   1MB messages = 16MB.

經(jīng)?？匆娋彺娴拇笮《际且晕坏拇笮《x，是因為習(xí)慣，還是因為什么原因？在實際項目中是否有什么策略根據(jù)自己需求來定義最優(yōu)的值來處理IO？