同样的读取方法，为什没p1方法比p2快了很多？

package TestDemo;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

//批量读取

public class InputDemo1 {

public static  void  p1(String  fileName) throws IOException{

File file1= new  File(fileName);

FileInputStream fis= new  FileInputStream(file1);

byte[] byte1=new  byte[20*1024];

int b=fis.read(byte1, 0, byte1.length);

int temp=1;

for(int i=0;i<b;i++){

System.out.print(Integer.toHexString(byte1[i]&0xff)+"  ");

if(temp++%10==0){

System.out.println();

}

}

fis.close();

}

public static void  p2(String fileName) throws IOException{

File file2= new  File(fileName);

FileInputStream fis2=new  FileInputStream(file2);

byte[] byte2=new  byte[20*1024];

int k=0;

int temp2=1;

while((k=fis2.read(byte2, 0, byte2.length))!=-1){

for (int i = 0; i <k; i++) {

System.out.print(Integer.toHexString(byte2[i]&0xff)+" ");

if(temp2++%10==0){

System.out.println();

}

}

}

fis2.close();

}

public static void main(String[] args) {

try {

long start=System.currentTimeMillis();

p1("E:\\JavaWeb.zip");

//p2("E:\\JavaWeb.zip");

long end=System.currentTimeMillis();

System.out.println((start-end)+"ms");

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}