HttpURLConnection

Question

URL rul = new URL(imageUrl);
HttpURLConnection connection =  (HttpURLConnection) rul.getContent();
connection.setRequestMethod("GET");
connection.setReadTimeout(3000);
return Drawable.createFromStream(connection.getInputStream(),
"image.png");
我去网上获得一个图片，在getgetInputStream()之前怎样判断这个图片是不是存在的呢？

Answer 1

get的时候好像有个返回值，从这个返回值判断的哦。

Answer 2

connection.getInputStream()通过获取流，检查数据包的头的属性及大小

Answer 3

connection.getResponseCode可以判断 正常返回200表示存在

Answer 4

给你段代码，我是写入文件try {
                            HttpGet request = new HttpGet(url);
                            HttpClient httpClient = new DefaultHttpClient();                            HttpResponse response = httpClient.execute(request);
                            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                                FileOutputStream fos = new FileOutputStream(f);
                                response.getEntity().writeTo(fos);
                                fos.flush();
                                fos.close();
                            } else {
                            }
                        } catch (Exception e) {
                            e.printStackTrace();
                        }