Obtain the IPv4 address through request. getremoteaddr () in Windows 7.

We often use request. getremoteaddr () to obtain remote IP Addresses During statistics or web development. You may encounter some problems. First, it may be that the value returned by this method is not the IP address we want, but a string of values 0: 0: 0: 0: 0: 1. If you know the TCP/IP protocol, you may know that it is an IPv6 protocol. Unfortunately, we want an IP address like 127.0.0.1. In fact, this situation occurs only when your server and your client are on the same machine.

Method 1:

The reason is that the file c: \ windows \ system32 \ drivers \ etc \ hosts contains the following two lines:

 

Code

1. #127.0.0.1 localhost
2. #: 1 localhost

 

These two are actually one for IPv6 and the other for IPv4. If it is win7, IPv6 is used by default. Therefore, the obtained value is 0: 0: 0: 0: 0: 0: 0: 0: 0: 1, XP will not have this problem. If win7 is used, the solution is to delete the line #: 1 localhost, or maintain this line as a comment and cancel #127.0.0.1
# Of the localhost line. Most articles on the Internet say that the solution here is to cancel the comment on this line. If you just cancel the comment, it means that the IPv6 protocol is used for connection, which may lead to an error in your database connection.

Of course, this issue is mainly caused by win7. Because only win7 uses IPv6.

Method 2:

Add -djava.net. preferipv4stack = true to the local Tomcat parameter so that Tomcat only supports IPv4.