字节缓冲流
//为什么要使用包装流，使用包装流是为了提高读写操作的性能。
public class Packing_flowDemo {
public static void main(String[] args) throws Exception {
File file = new File("file/packing_flow.txt");
//包装流的写法，缓冲区内存大小。1024*8=8192 (byte)
// BufferedOutputStream packing = new BufferedOutputStream(new FileOutputStream(file, true));
// packing.write("大家好！你好吗？how are your !".getBytes());
// packing.close();
//包装流的读写操作。
BufferedInputStream outPacking = new BufferedInputStream(new FileInputStream(file));
byte[] buffer = new byte[1024];
int len = -1;
while ((len = outPacking.read(buffer)) != -1) {
System.out.println(new String(buffer, 0, len));
}
}
}
public static void main(String[] args) throws IOException {//为了代码看起来美观一些，直接抛出去
File file=new File("moves/许嵩 - 素颜 - 现场版.mp3");
File file1=new File("moves/许嵩 - 素颜.mp3");
//text(file, file1);
//text2(file, file1);
//text3(file, file1);
text4(file, file1);
}
private static void text(File file,File file1) throws IOException {
//节点流的方法，一个一个字节的读和写
long begin=System.currentTimeMillis();
FileInputStream in=new FileInputStream(file);
FileOutputStream out =new FileOutputStream(file1);
int len=-1;
while((len=in.read())!=-1){
out.write(len);
}
in.close();
out.close();
System.out.println(System.currentTimeMillis()-begin);//5547毫秒
}
private static void text2(File file,File file1) throws IOException {
//缓冲流的写法，一个一个字节的读和写
long begin=System.currentTimeMillis();
BufferedInputStream in=new BufferedInputStream(new FileInputStream(file));
BufferedOutputStream out =new BufferedOutputStream(new FileOutputStream(file1));
int len=-1;
while(in.read()!=-1){
out.write(len);
}
in.close();
out.close();
System.out.println(System.currentTimeMillis()-begin);//63毫秒
}
private static void text3(File file,File file1) throws IOException {
//节点流的写法，一次性读取1024个字节
long begin=System.currentTimeMillis();
FileInputStream in=new FileInputStream(file);
FileOutputStream out =new FileOutputStream(file1);
int len=-1;
byte[] buffer=new byte[1024];
while((len=in.read(buffer))!=-1){
out.write(buffer,0,len);
}
in.close();
out.close();
System.out.println(System.currentTimeMillis()-begin);//38毫秒
}
private static void text4(File file,File file1) throws IOException {
//缓冲流的写法，一次性读取1024个字节
long begin=System.currentTimeMillis();
BufferedInputStream in=new BufferedInputStream(new FileInputStream(file));
BufferedOutputStream out =new BufferedOutputStream(new FileOutputStream(file1));
int len=-1;
byte[] buffer=new byte[1024];
while((len=in.read(buffer))!=-1){
out.write(buffer,0,len);
}
in.close();
out.close();
System.out.println(System.currentTimeMillis()-begin);//4毫秒
}