java url获取数据 openStream

 1 try {
 2   URL u = new URL("网址");
 3   InputStream in = u.openStream();
 4   int c;
 5   while((c = in.read()) != -1) 
 6             System.out.write(c);
 7   in.close();
 8 } catch(IOException e) {
 9 
10 }