public int read(byte[] b)
  throws IOException

ServerSocket server = new ServerSocket(port)
Socket client = server.accept();
BufferedInputStream bis = new BufferedInputStream(client.getInputStream);

byte[] box = new byte[1024];
int len = 0;
while(-1!=(len = bis.read(box))) {
 System.out.println(len);
 String msg = new String(box, 0, len);
}語(yǔ)句1;語(yǔ)句二;

public class Test{
 public static void main(String[] args) throws Exception {
 UseTimeTool.getInstance().start();
 FileInputStream fis = new FileInputStream("D:\\1.mp3");
 FileOutputStream fos = new FileOutputStream("D:\\1copy.mp3");
 //(PS:一下3個(gè)大家分開來(lái)寫和測(cè)試,為了方便我都列出來(lái)了)
 /*--------------不使用緩沖--------------*/
 //如果不緩沖,花了差不多14"秒"
 int len = -1;
 while ((len = fis.read()) != -1) {
  //這里就不是長(zhǎng)度的問(wèn)題了,而是讀取的字節(jié)"內(nèi)容",讀到一個(gè)寫一個(gè),相當(dāng)慢.
  System.out.println("len : "+ len); 
  fos.write(len);
 }
 /*--------------使用緩沖--------------*/
 //緩沖方法復(fù)制歌曲用了不到20"毫秒"
 //創(chuàng)建一個(gè)長(zhǎng)度為1024的字節(jié)數(shù)組,每次都讀取5kb,目的是緩存,如果不用緩沖區(qū),用fis.read(),就會(huì)效率低,一個(gè)一個(gè)讀字節(jié),緩沖區(qū)是一次讀5000個(gè)
 byte[] bytes = new byte[1024*5];
 //每次都是從讀取流中讀取(5k)長(zhǎng)度的數(shù)據(jù),然后再寫到文件去(5k的)數(shù)據(jù),注意,每次讀取read都會(huì)不同,是獲取到下一個(gè),直到后面最后一個(gè).
 while (fis.read(bytes)!=-1) {
  //write是最追加到文件后面,所以直接每次添5K.
  fos.write(bytes); 
 }
 /*--------------解釋len--------------*/
 //告訴你為什么用len
 byte[] bytes = new byte[1024*5];
 int len = -1;
 //解釋這個(gè)fis.read(bytes)的意思:從讀取流"讀取數(shù)組長(zhǎng)度"的數(shù)據(jù)(打印len可知),并放入數(shù)組
 while ((len = fis.read(bytes,0,1024)) != -1) {
  //雖然數(shù)組長(zhǎng)度的*5,但是這里我們?cè)O(shè)置了1024所以每次輸出1024
  System.out.println("len : "+ len);
  //因?yàn)槊看蔚玫降氖切碌臄?shù)組,所以每次都是新數(shù)組的"0-len"
  fos.write(bytes,0,len);
 }
 fis.close();
 fos.close();
 UseTimeTool.getInstance().stop();
 }
}

class UseTimeTool {
 private static UseTimeTool utt = new UseTimeTool();
 private UseTimeTool() {
 }
 public static UseTimeTool getInstance() {
 return utt;
 }
 private long start;
 public void start() {
 start = System.currentTimeMillis();
 }
 public void stop() {
 long end = System.currentTimeMillis();
 System.out.println("所用時(shí)間 : " + (end - start) + "毫秒");
 }
}

public class Test{
 public static void main(String[] args) throws Exception {
 UseTimeTool.getInstance().start();
 FileInputStream fis = new FileInputStream("D:\\a.txt");
 FileOutputStream fos = new FileOutputStream("D:\\acopy.txt");

byte[] bytes = new byte[1024*5];
 while (fis.read(bytes)!=-1) {
  fos.write(bytes); 
 }

byte[] bytes = new byte[1024*5];
 int len = -1;
 while ((len = fis.read(bytes,0,1024)) != -1) {
  fos.write(bytes,0,len);
 }