Java gets the local host name and IP address

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Java gets the local host name and IP address

1. Knowledge explanation

1. Get the InetAddress class

(1) Obtain information about the local computer

InetAddress i = InetAddress.getLocalHost();

(2) Obtain computer-related information through the computer name
Among them, the parameter host in the method can be the host alias or the host IP. Example: "Person-PC", "www.126.com", "10.0.70.30", "220.181.72.180"

String host = "Person-PC";
InetAddress i = InetAddress.getByName(host);

2. Get the host name

(1) Get the host alias

String hostName = i.getHostName();

(2) Obtain the host name (sometimes the host name is the same as the host alias, and sometimes the host name is the same as the host IP)

String canonicalHostName = i.getCanonicalHostName();

3. Obtain the host IP

(1) Obtain the host IP (IP address in the form of a string)

String address = i.getHostAddress();

(2) Obtain the host IP (IP address in the form of byte array)

byte[] address = i.getAddress();

2. Application cases

    public static void main(String[] args) {
    
    
        try {
    
    
            String[] hosts = {
    
    "Person-PC", "www.126.com", "10.0.70.30", "220.181.72.180"};
            for (String host : hosts) {
    
    
                // 获取 InetAddress 类
                InetAddress i = InetAddress.getByName(host); // 通过计算机名称获取计算机相关信息
                // 获取主机名
                String hostName = i.getHostName(); // 获取主机别名，如：Person-PC
                String canonicalHostName = i.getCanonicalHostName(); // 获取主机名（有时出现主机名与主机别名相同，有时出现主机名与主机IP相同），如：Person-PC
                // 获取主机IP
                String hostAddress = i.getHostAddress(); //获取主机IP（字符串形式的IP地址），如： 10.0.70.30
                byte[] address = i.getAddress(); //获取主机IP（byte数组形式的IP地址），如：[B@78308db1

                // 打印
                System.out.println("host：" + host);
                System.out.println("主机别名：" + hostName);
                System.out.println("主机名：" + canonicalHostName);
                System.out.println("主机IP（字符串形式）：" + hostAddress);
                System.out.println("主机名（byte数组形式）：" + address);
                System.out.println();
            }
        } catch (UnknownHostException e) {
    
    
            e.printStackTrace();
        }
    }

Output result:

host：Person-PC
主机别名：Person-PC
主机名：Person-PC
主机IP（字符串形式）：10.0.70.30
主机名（byte数组形式）：[B@78308db1

host：www.126.com
主机别名：www.126.com
主机名：220.181.72.180
主机IP（字符串形式）：220.181.72.180
主机名（byte数组形式）：[B@27c170f0

host：10.0.70.30
主机别名：Person-PC
主机名：Person-PC
主机IP（字符串形式）：10.0.70.30
主机名（byte数组形式）：[B@5451c3a8

host：220.181.72.180
主机别名：220.181.72.180
主机名：220.181.72.180
主机IP（字符串形式）：220.181.72.180
主机名（byte数组形式）：[B@2626b418