简易实现图片下载

String str = null;
int size;
byte[] bytes = new byte[1024];

File file = new File("缓存目录");
URL url = new URL("图片链接");

BufferedInputStream bis = new BufferedInputStream(url.openStream());
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file));

while((size = bis.read(bytes)) != -1){
    bos.write(bytes,0,size);
}

bos.close();
bis.close();