ImageIO.read(Socket.getInputStream())结果为空

下面是代码，请各位高手帮忙
int serverNameStart = picURL.indexOf("http://")+7;
int serverNameEnd = picURL.indexOf("/",serverNameStart);

String serverName = picURL.substring(serverNameStart, serverNameEnd);
String newUrl = picURL.substring(serverNameEnd);
if(newUrl.equals("/")){
newUrl = picURL;
}
System.out.println(newUrl);
Socket clientSocket = null;
clientSocket = new Socket(serverName,80);
PrintStream ps =  new PrintStream(clientSocket.getOutputStream());
//设置虚假http头
ps.println("GET "+newUrl+" HTTP/1.1");
ps.println("Host:"+serverName); 
ps.println("Accept:*/* "); 
ps.println("Referer:www.baidu.com");
ps.println("User-Agent:Baiduspider");
ps.println("X_FORWARDED_FOR:202.108.22.5");
ps.println();
ps.flush();

InputStream is = clientSocket.getInputStream();Calendar cal = Calendar.getInstance();
java.sql.Date today = new java.sql.Date(cal.get(Calendar.YEAR)-1900,
cal.get(Calendar.MONTH),cal.get(Calendar.DAY_OF_MONTH));//系统日期
String timePath = today.toString();

File picFilePath = new File("F:/collection/collection/web/pic/"+picPath+"/"+timePath);
if((!picFilePath.exists())&&(!picFilePath.isDirectory())){
picFilePath.mkdirs();
}
File picFile = new File(picFilePath.toString()+"/"+picURL.substring(picURL.lastIndexOf("/")+1));
FileOutputStream fos = new FileOutputStream(picFile);
Image image = javax.imageio.ImageIO.read(is);
    int width = image.getWidth(null);   
    int height = image.getHeight(null); 
    BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    bufferedImage.getGraphics().drawImage(image, 0, 0, width, height,null);
         
    JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(fos);
encoder.encode(bufferedImage); 
    fos1.close();