1.获取可用端口工具类

import java.net.InetAddress;
import java.net.Socket;
import java.util.Random;public class ServerPortUtil {private static final int MAX_PORT = 65535;private static final int MIN_PORT = 8000;public static String getAvailablePort() {Random random = new Random();// 最大尝试次数为端口范围int maxRetryCount = MAX_PORT - MIN_PORT;while (maxRetryCount > 0) {// 指定范围内随机端口，随便写的算法，根据自己需要调整int port = random.nextInt(MAX_PORT - MIN_PORT) + MIN_PORT;boolean isUsed = isLocalePortUsing(port);if (!isUsed) {return String.valueOf(port);}--maxRetryCount;}System.out.println("系统暂无端口可用，运行结束");System.exit(1);return null;}/*** 检查给定端口是否可用** @author tianxincode@163.com* @since 2020/10/14*/public static boolean isLocalePortUsing(int port) {try {// 建立一个Socket连接, 如果该端口还在使用则返回true, 否则返回false, 127.0.0.1代表本机new Socket(InetAddress.getByName("127.0.0.1"), port);return true;} catch (Exception e) {// 异常说明端口连接不上，端口能使用}return false;}
}

2.获取到可用端口将端口信息写入运行环境中

import com.codecoord.randomport.util.ServerPortUtil;
import org.springframework.util.StringUtils;public class StartCommand {/*** 端口属性名称，如果名称为server.port则在配置文件中不用指定，否则需要指定为此处配置的名称，如${auto.port}*/private static final String SERVER_PORT = "auto.port";public StartCommand(String[] args) {boolean isServerPort = false;String serverPort = "";if (args != null) {for (String arg : args) {if (StringUtils.hasText(arg) && arg.startsWith("--server.port" )) {isServerPort = true;serverPort = arg;break;}}}String port;if (isServerPort) {port = serverPort.split("=")[1];} else {port = ServerPortUtil.getAvailablePort();}System.out.println("Current project port is " + port);System.setProperty(SERVER_PORT, port);}
}

3.SpringBoot启动前调用 

import com.codecoord.randomport.config.StartCommand;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplicatio
public class SpringbootRandomPortApplication {public static void main(String[] args) {// 写入端口信息 new StartCommand(args);SpringApplication.run(SpringbootRandomPortApplication.class, args);}
}

4.修改配置文件

server:# 随机端口配置port: ${auto.port}