Question

java中URL下载文件的问题。程序有问题，下载的mp3文件比原来的大，请问问题出在哪里？

class DownFile {
public static void main(String[] args){
URL url = null;
InputStream is = null;
FileOutputStream fos = null;
try{
url = new URL("http://yinyueshiting.baidu.com/data2/music/121524984/12152327672000128.mp3?xcode=6de82a6019a0fd028ddb2ac4c63c2a556f8d94595cf48717");
URLConnection urlConn = url.openConnection();
System.out.println("文件大小： "+urlConn.getContentLength());
byte[] bfr = new byte [2048];
is = urlConn.getInputStream();
fos = new FileOutputStream("e:\\abc\\平凡之路.mp3");
while ((is.read(bfr)) != -1){
fos.write(bfr);
}
fos.flush();
System.out.println("下载完毕");

}catch(Exception e){
e.printStackTrace();
}finally{
try{
if (is != null)
is.close();
if (fos != null)
fos.close();
}catch(Exception e){}
}
}
}

Answer 1

is.read()的返回实际从网上读取的字节数，而你是只按2KB写入，导致多写

整个while改成

int c;
while ((c=is.read(bfr))!=-1){
     fos.write(bfr,0,c);
}

Answer 2

int len=0;

while ((len=is.read(bfr))>0){
fos.write(bfr,0,len);
}