安全使用 HttpURLConnection

When using HttpURLConnection does the InputStream need to be closed if we do not 'get' and use it?

即这安全吗?

HttpURLConnection conn = (HttpURLConnection) uri.getURI().toURL().openConnection();
conn.connect();
// check for content type I don't care about
if (conn.getContentType.equals("image/gif") return; 
// get stream and read from it
InputStream is = conn.getInputStream();
try {
    // read from is
} finally {
    is.close();
}

其次，在 InputStream 的所有内容被完全读取之前关闭它是否安全?