Java 获取网络上的文件

Java 获取网络上的文件

/**
* 获取网络上的图片
* @param URLName 地址
* @throws Exception
*/
public InputStream getUrlImg(String URLName) throws Exception {
ByteArrayOutputStream os = new ByteArrayOutputStream();
int HttpResult = 0; //服务器返回的状态
URL url = new URL(URLName); //创建URL
URLConnection urlconn = url.openConnection(); // 试图连接并取得返回状态码urlconn.connect();
HttpURLConnection httpconn = (HttpURLConnection) urlconn;
HttpResult = httpconn.getResponseCode();
System.out.println(HttpResult);
if (HttpResult != HttpURLConnection.HTTP_OK){  //不等于HTTP_OK说明连接不成功
System.out.print("连接失败！");
}else {
int filesize = urlconn.getContentLength();  //取数据长度
System.out.println(filesize);
BufferedInputStream bis=new BufferedInputStream(urlconn.getInputStream());
BufferedOutputStream bos=new BufferedOutputStream(os);
byte[] buffer = new byte[1024]; //创建存放输入流的缓冲
int num = -1; //读入的字节数
while (true) {
num = bis.read(buffer); // 读入到缓冲区
if (num ==-1){
bos.flush();
break; //已经读完
}
bos.flush();
bos.write(buffer,0,num);
}
bos.close();
bis.close();
}
ByteArrayInputStream bis = new ByteArrayInputStream(os.toByteArray());
return bis;
}