spring-boot有一个根据JVM变量-Dspring.profiles.active来设置运行时的active profile的功能，但是有些时候我们也许会不小心忘记设置这个变量，这样在生产环境中会带来一定的困扰，所以我想了一个办法，来给忘记设置-Dspring.profiles.active的程序员一次“secend chance”。

先来讲一下思路：

• step0 约定好profiles的命名，“development”代表开发环境(也可以将默认的profile设为开发环境)，“production”代表生产环境
• step1 判断是否设置了-Dspring.profiles.active，如果已经设置，直接跳转step3
• step2 判断当前操作系统环境，如果不是Linux环境则认定为开发环境，自动倒计时激活开发的profile；如果是Linux环境则认定为生产环境，输出选择profile的控制台信息，并等待用户控制台输入进行选择，并依据用户选择来激活profile
• step3 SpringApplication.run()

代码如下：

spring-boot配置文件(使用了默认profile作为开发环境)：

spring:application:name: comchangyoueurekaserver #注意命名要符合RFC 2396，否则会影响服务发现 详见https://stackoverflow.com/questions/37062828/spring-cloud-brixton-rc2-eureka-feign-or-rest-template-configuration-not-worserver:port: 8001eureka:instance:hostname: localhostclient:registerWithEureka: falsefetchRegistry: falseserviceUrl:defaultZone: http://${eureka.instance.hostname}:${server.port}---
spring:profiles: productionapplication:name: comchangyoueurekaserverserver:port: 8001eureka:instance:hostname: localhostclient:registerWithEureka: falsefetchRegistry: falseserviceUrl:defaultZone: http://${eureka.instance.hostname}:${server.port}
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BootStarter封装了step1-step3的逻辑：

import org.apache.commons.lang3.StringUtils;import java.util.Scanner;
import java.util.Timer;
import java.util.TimerTask;
import java.util.regex.Pattern;public class BootStarter {//用于后续Spring Boot操作的回调public interface Callback {void bootRun();}private boolean enableAutomaticallyStart = true;private int automaticallyStartDelay = 10;public boolean isEnableAutomaticallyStart() {return enableAutomaticallyStart;}public void setEnableAutomaticallyStart(boolean enableAutomaticallyStart) {this.enableAutomaticallyStart = enableAutomaticallyStart;}public int getAutomaticallyStartDelay() {return automaticallyStartDelay;}public void setAutomaticallyStartDelay(int automaticallyStartDelay) {this.automaticallyStartDelay = automaticallyStartDelay;}public void startup(boolean enableAutomaticallyStart, int automaticallyStartDelay, Callback callback) {if (StringUtils.isBlank(System.getProperty("spring.profiles.active"))) { //如果没有通过参数spring.profiles.active设置active profile则让用户在控制台自己选择System.out.println("***Please choose active profile:***\n\tp: production\n\td: development");final boolean[] started = {false};Timer timer = new Timer();if (enableAutomaticallyStart && System.getProperty("os.name").lastIndexOf("Linux") == -1) { //如果当前操作系统环境为非Linux环境(一般为开发环境)则automaticallyStartDelay秒后自动设置为开发环境System.out.printf("\nSystem will automatically select 'd' in %d seconds.\n", automaticallyStartDelay);final int[] count = {automaticallyStartDelay};timer.scheduleAtFixedRate(new TimerTask() {@Overridepublic void run() {if (count[0]-- == 0) {timer.cancel();started[0] = true;System.setProperty("spring.profiles.active", "development");callback.bootRun();}}}, 0, 1000);}Scanner scanner = new Scanner(System.in);Pattern pattern = Pattern.compile("^p|d$");//如果是Linux系统(一般为生产环境)则强制等待用户输入(一般是忘记设置spring.profiles.active了，这等于给了设置active profile的"second chance")while (scanner.hasNextLine()) {if (started[0]) {break;}String line = scanner.nextLine();if (!pattern.matcher(line).find()) {System.out.println("INVALID INPUT!");} else {timer.cancel();System.setProperty("spring.profiles.active", line.equals("d") ? "development" : "production");callback.bootRun();break;}}} else { //如果已经通过参数spring.profiles.active设置了active profile直接启动callback.bootRun();}}public void startup(Callback callback) {startup(this.enableAutomaticallyStart, this.automaticallyStartDelay, callback);}
}复制代码

main()：

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
import org.springframework.context.ApplicationContext;@EnableEurekaServer
@SpringBootApplication
public class App {private static final Logger LOGGER = LoggerFactory.getLogger(App.class);public static void main(String[] args) {new BootStarter().startup(() -> {ApplicationContext applicationContext = SpringApplication.run(App.class, args);for (String activeProfile : applicationContext.getEnvironment().getActiveProfiles()) {LOGGER.warn("***Running with profile: {}***", activeProfile);}});}
}
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运行效果(开发环境Mac OS)：

扩展： 其实在这里我们还可以发散一下思维，基于spring-boot的应用比起传统spring应用的一大优势是自己可以掌控main()方法，有了这一点，我们是能玩出很多花样来的，思路不要被局限在tomcat时代了。

main法在手，天下我有。

2017-1-22更新：增加了线程安全的处理

import org.apache.commons.lang3.StringUtils;import java.util.Scanner;
import java.util.Timer;
import java.util.TimerTask;
import java.util.regex.Pattern;public class BootStarter {private volatile boolean started;//用于后续Spring Boot操作的回调public interface Callback {void bootRun();}private boolean enableAutomaticallyStart = true;private int automaticallyStartDelay = 3;public boolean isEnableAutomaticallyStart() {return enableAutomaticallyStart;}public void setEnableAutomaticallyStart(boolean enableAutomaticallyStart) {this.enableAutomaticallyStart = enableAutomaticallyStart;}public int getAutomaticallyStartDelay() {return automaticallyStartDelay;}public void setAutomaticallyStartDelay(int automaticallyStartDelay) {this.automaticallyStartDelay = automaticallyStartDelay;}public void startup(boolean enableAutomaticallyStart, int automaticallyStartDelay, Callback callback) {if (StringUtils.isBlank(System.getProperty("spring.profiles.active"))) { //如果没有通过参数spring.profiles.active设置active profile则让用户在控制台自己选择System.out.println("***Please choose active profile:***\n\tp: production\n\td: development");Timer timer = new Timer();if (enableAutomaticallyStart && System.getProperty("os.name").lastIndexOf("Linux") == -1) { //如果当前操作系统环境为非Linux环境(一般为开发环境)则automaticallyStartDelay秒后自动设置为开发环境System.out.printf("\nSystem will automatically select 'd' in %d seconds.\n", automaticallyStartDelay);timer.scheduleAtFixedRate(new TimerTask() {private ThreadLocal<Integer> countDown = ThreadLocal.withInitial(() -> automaticallyStartDelay);@Overridepublic void run() {if (countDown.get() == 0) {timer.cancel();started = true;System.setProperty("spring.profiles.active", "development");callback.bootRun();}countDown.set(countDown.get() - 1);}}, 0, 1000);}Scanner scanner = new Scanner(System.in);Pattern pattern = Pattern.compile("^p|d$");//如果是Linux系统(一般为生产环境)则强制等待用户输入(一般是忘记设置spring.profiles.active了，这等于给了设置active profile的"second chance")while (scanner.hasNextLine()) {if (started) {break;}String line = scanner.nextLine();if (!pattern.matcher(line).find()) {System.out.println("INVALID INPUT!");} else {timer.cancel();System.setProperty("spring.profiles.active", line.equals("d") ? "development" : "production");callback.bootRun();break;}}} else { //如果已经通过参数spring.profiles.active设置了active profile直接启动callback.bootRun();}}public void startup(Callback callback) {startup(this.enableAutomaticallyStart, this.automaticallyStartDelay, callback);}
}复制代码

2017-01-25更新：

补上了 try-with-resource

import org.apache.commons.lang3.StringUtils;import java.util.Scanner;
import java.util.Timer;
import java.util.TimerTask;
import java.util.regex.Pattern;public class BootStarter {private volatile boolean started;//用于后续Spring Boot操作的回调public interface Callback {void bootRun();}private boolean enableAutomaticallyStart = true;private int automaticallyStartDelay = 3;public boolean isEnableAutomaticallyStart() {return enableAutomaticallyStart;}public void setEnableAutomaticallyStart(boolean enableAutomaticallyStart) {this.enableAutomaticallyStart = enableAutomaticallyStart;}public int getAutomaticallyStartDelay() {return automaticallyStartDelay;}public void setAutomaticallyStartDelay(int automaticallyStartDelay) {this.automaticallyStartDelay = automaticallyStartDelay;}public void startup(boolean enableAutomaticallyStart, int automaticallyStartDelay, Callback callback) {if (StringUtils.isBlank(System.getProperty("spring.profiles.active"))) { //如果没有通过参数spring.profiles.active设置active profile则让用户在控制台自己选择System.out.println("***Please choose active profile:***\n\tp: production\n\td: development");Timer timer = new Timer();if (enableAutomaticallyStart && System.getProperty("os.name").lastIndexOf("Linux") == -1) { //如果当前操作系统环境为非Linux环境(一般为开发环境)则automaticallyStartDelay秒后自动设置为开发环境System.out.printf("\nSystem will automatically select 'd' in %d seconds.\n", automaticallyStartDelay);timer.scheduleAtFixedRate(new TimerTask() {private ThreadLocal<Integer> countDown = ThreadLocal.withInitial(() -> automaticallyStartDelay);@Overridepublic void run() {if (countDown.get() == 0) {timer.cancel();started = true;System.setProperty("spring.profiles.active", "development");callback.bootRun();}countDown.set(countDown.get() - 1);}}, 0, 1000);}try (Scanner scanner = new Scanner(System.in)) {Pattern pattern = Pattern.compile("^p|d$");//如果是Linux系统(一般为生产环境)则强制等待用户输入(一般是忘记设置spring.profiles.active了，这等于给了设置active profile的"second chance")while (scanner.hasNextLine()) {if (started) {break;}String line = scanner.nextLine();if (!pattern.matcher(line).find()) {System.out.println("INVALID INPUT!");} else {timer.cancel();System.setProperty("spring.profiles.active", line.equals("d") ? "development" : "production");callback.bootRun();break;}}}} else { //如果已经通过参数spring.profiles.active设置了active profile直接启动callback.bootRun();}}public void startup(Callback callback) {startup(this.enableAutomaticallyStart, this.automaticallyStartDelay, callback);}
}复制代码