是否在JDK中定义了HTTP和HTTPS默认端口号？

Question

我试图查看端口80和端口443是否被定义为公共常量。这些是否存在于JDK中（或者可能存在于Apache HttpClient等公共库中）？

Answer 1

查看Javadoc的URL：http://docs.oracle.com/javase/8/docs/api/java/net/URL.html#getDefaultPort--

getDefaultPort()返回给定协议的端口

URL url = new URL("http://blah.com");
int defaultPort = url.getDefaultPort();

Answer 2

Apache HttpClient确实将它们作为整数常量：

• http://hc.apache.org/httpclient-3.x/apidocs/org/apache/commons/httpclient/HttpURL.html#DEFAULT_PORT
• http://hc.apache.org/httpclient-3.x/apidocs/org/apache/commons/httpclient/HttpsURL.html#DEFAULT_PORT