数据流

public void copy(){

InputStream in=null;

OutputStream out=null;

try {

//建立读取和写入流

in=new FileInputStream("src\\mapTest\\test.txt");

out=new FileOutputStream("pro.txt");

int len=0;

byte[] by=new byte[1024];

while((len=in.read(by))!=-1){

//写入byte数组中的数据，读了几个字节就写入几个字节

out.write(by,0,len);

}

} catch (Exception e) {

e.printStackTrace();

}finally{

try {

//关闭流，后建立先关闭

out.close();

in.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}