我知道https扩展了http。那是不是意味着我能做到?
HttpUrlConnection connect = passmyurl.openconnection(url);
和
HttpsUrlConnection connect = passmyurl.openconnection(url);
public static HttpsURLConnection passmyurl(URL url) throws IOException {
HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
return connection;
}
这是否意味着两者都能奏效?因为https扩展了http,这意味着我也可以向这个函数传递一个http url?
最佳答案
在你的代码中:
public static HttpsURLConnection passmyurl(URL url) throws IOException {
HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
return connection;
}
您应该将返回类型
HttpsURLConnection
更改为URLConnection
。因为url.openConnection()
结果的类型是URLConnection
的子类型,而确切的类型取决于参数url
的协议。openConnection()
类中URL
的实现文档:If for the URL's protocol (such as HTTP or JAR), there exists a public, specialized URLConnection subclass belonging to one of the following packages or one of their subpackages: java.lang, java.io, java.util, java.net, the connection returned will be of that subclass. For example, for HTTP an HttpURLConnection will be returned, and for JAR a JarURLConnection will be returned.
因此您可以将
Http
url或Https
url传递给您的方法。请参见以下代码:
URLConnection httpConnection = new URL("http://test").openConnection();
System.out.println(httpConnection.getClass());
URLConnection httpsConnection = new URL("https://test").openConnection();
System.out.println(httpsConnection.getClass());
URLConnection ftpConnection = new URL("ftp://test").openConnection();
System.out.println(ftpConnection.getClass());`
印刷品是:
class sun.net.www.protocol.http.HttpURLConnection
class sun.net.www.protocol.https.HttpsURLConnectionImpl
class sun.net.www.protocol.ftp.FtpURLConnection
关于java - Java中的HTTPS和HTTP连接,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/44425397/