SpringBoot工程可以在main方法中执行SpringApplication.run()这种方式来启动。
```
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
} * 如果我们需要在SpringBoot启动过程中添加一些定制代码（如定制启动Banner，设置自定义监听器等，设置启动拓展，设置启动环境变量），这种方式就无法满足我们的要求了。 * 比如我们现在要定制启动Banner，那么有如下两种方式。
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication application = new SpringApplication(Application.class);
application.setBannerMode(Banner.Mode.OFF);
application.run(args);
}
}
@SpringBootApplication
public class Application {
public static void main(String[] args) {
new SpringApplicationBuilder()
.sources(Application.class)
.bannerMode(Banner.Mode.OFF)
.run(args);
}
}
```
* 只是定制一个banner，代码就得如此，并不是很优雅，倘若我们有很多个微服务，那每个微服务都这么写，代码必定会显得很冗余。
* 所以我们需要有一个优雅的解决方案，使得每个微服务都调用自定义的启动器，这样最终呈现效果就能如原生一样简洁优雅。
SpringApplicationBuilder，将其封装进一个核心类中进行拓展，以便于微服务启动之用。@author Chill
*/
public class BladeApplication {
/**
* Create an application context
* java -jar app.jar --spring.profiles.active=prod --server.port=2333
*
* @param appName application name
* @param source The sources
* @return an application context created from the current state
*/
public static ConfigurableApplicationContext run(String appName, Class source, String... args) {
SpringApplicationBuilder builder = createSpringApplicationBuilder(appName, source, args);
return builder.run(args);
}
public static SpringApplicationBuilder createSpringApplicationBuilder(String appName, Class source, String... args) {
Assert.hasText(appName, "[appName]服务名不能为空");
// 读取环境变量，使用spring boot的规则
ConfigurableEnvironment environment = new StandardEnvironment();
MutablePropertySources propertySources = environment.getPropertySources();
propertySources.addFirst(new SimpleCommandLinePropertySource(args));
propertySources.addLast(new MapPropertySource(StandardEnvironment.SYSTEM_PROPERTIES_PROPERTY_SOURCE_NAME, environment.getSystemProperties()));
propertySources.addLast(new SystemEnvironmentPropertySource(StandardEnvironment.SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME, environment.getSystemEnvironment()));
// 获取配置的环境变量
String[] activeProfiles = environment.getActiveProfiles();
// 判断环境:dev、test、prod
List profiles = Arrays.asList(activeProfiles);
// 预设的环境
List presetProfiles = new ArrayList<>(Arrays.asList(AppConstant.DEV_CODE, AppConstant.TEST_CODE, AppConstant.PROD_CODE));
// 交集
presetProfiles.retainAll(profiles);
// 当前使用
List activeProfileList = new ArrayList<>(profiles);
Function<Object[], String> joinFun = StringUtils::arrayToCommaDelimitedString;
SpringApplicationBuilder builder = new SpringApplicationBuilder(source);
String profile;
if (activeProfileList.isEmpty()) {
// 默认dev开发
profile = AppConstant.DEV_CODE;
activeProfileList.add(profile);
builder.profiles(profile);
} else if (activeProfileList.size() == 1) {
profile = activeProfileList.get(0);
} else {
// 同时存在dev、test、prod环境时
throw new RuntimeException("同时存在环境变量:[" + StringUtils.arrayToCommaDelimitedString(activeProfiles) + "]");
}
String startJarPath = BladeApplication.class.getResource("/").getPath().split("!")[0];
String activePros = joinFun.apply(activeProfileList.toArray());
System.out.printf("----启动中，读取到的环境变量:[%s]，jar地址:[%s]----%n", activePros, startJarPath);
Properties props = System.getProperties();
props.setProperty("spring.application.name", appName);
props.setProperty("spring.profiles.active", profile);
props.setProperty("info.version", AppConstant.APPLICATION_VERSION);
props.setProperty("info.desc", appName);
props.setProperty("file.encoding", StandardCharsets.UTF_8.name());
props.setProperty("blade.env", profile);
props.setProperty("blade.name", appName);
props.setProperty("blade.is-local", String.valueOf(isLocalDev()));
props.setProperty("blade.dev-mode", profile.equals(AppConstant.PROD_CODE) ? "false" : "true");
props.setProperty("blade.service.version", AppConstant.APPLICATION_VERSION);
Properties defaultProperties = new Properties();
defaultProperties.setProperty("spring.main.allow-bean-definition-overriding", "true");
defaultProperties.setProperty("spring.sleuth.sampler.percentage", "1.0");
defaultProperties.setProperty("spring.cloud.alibaba.seata.tx-service-group", appName.concat(NacosConstant.NACOS_GROUP_SUFFIX));
defaultProperties.setProperty("spring.cloud.nacos.config.file-extension", NacosConstant.NACOS_CONFIG_FORMAT);
defaultProperties.setProperty("spring.cloud.nacos.config.shared-configs[0].data-id", NacosConstant.sharedDataId());
defaultProperties.setProperty("spring.cloud.nacos.config.shared-configs[0].group", NacosConstant.NACOS_CONFIG_GROUP);
defaultProperties.setProperty("spring.cloud.nacos.config.shared-configs[0].refresh", NacosConstant.NACOS_CONFIG_REFRESH);
defaultProperties.setProperty("spring.cloud.nacos.config.shared-configs[1].data-id", NacosConstant.sharedDataId(profile));
defaultProperties.setProperty("spring.cloud.nacos.config.shared-configs[1].group", NacosConstant.NACOS_CONFIG_GROUP);
defaultProperties.setProperty("spring.cloud.nacos.config.shared-configs[1].refresh", NacosConstant.NACOS_CONFIG_REFRESH);
builder.properties(defaultProperties);
// 加载自定义组件
List launcherList = new ArrayList<>();
ServiceLoader.load(LauncherService.class).forEach(launcherList::add);
launcherList.stream().sorted(Comparator.comparing(LauncherService::getOrder)).collect(Collectors.toList())
.forEach(launcherService -> launcherService.launcher(builder, appName, profile, isLocalDev()));
return builder;
}
/**
* 判断是否为本地开发环境
*
* @return boolean
*/
public static boolean isLocalDev() {
String osName = System.getProperty("os.name");
return StringUtils.hasText(osName) && !(AppConstant.OS_NAME_LINUX.equalsIgnoreCase(osName));
}
}
~~~
blade-demo模块启动为例，看下代码public static void main(String[] args) {
BladeApplication.run(CommonConstant.APPLICATION_DEMO_NAME, DemoApplication.class, args);
}
}
~~~
* 可以看到非常简约，与原生并没有太多变化，只是多了一个appName的参数，此参数正是做为服务名注册到注册中心，用于和其他服务分类。
application.yml中配置spring.profiles.active再打包。spring.profiles.active，则默认为dev，如需设置只需在启动的命令行加上即可。java -jar app.jar --spring.profiles.active=prod --server.port=2333一次打包，处处运行的理念。DEV环境，可参考如下配置。