spring cloud config配置中心源码分析之注解@EnableConfigServer

spring cloud config的主函数是ConfigServerApplication，其定义如下：

@Configuration
@EnableAutoConfiguration
@EnableConfigServer
public class ConfigServerApplication {

public static void main(String[] args) {
new SpringApplicationBuilder(ConfigServerApplication.class)
.properties("spring.config.name=configserver").run(args);
}

}

其中

@Configuration是spring定义的注解，使用注解，配置信息的载体由 XML 文件转移到了 Java 类中。

@EnableAutoConfiguration是spring boot定义的注解，控制spring applicationContext的自动配置的开关。

@EnableConfigServer是spring cloud定义的注解，

@EnableConfigServer定义如下：

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import({ ResourceRepositoryConfiguration.class, EnvironmentRepositoryConfiguration.class,
ConfigServerEncryptionConfiguration.class, ConfigServerMvcConfiguration.class })
public @interface EnableConfigServer {

}

1. ResourceRepositoryConfiguration

定义如下：

@Configuration
@EnableConfigurationProperties(ConfigServerProperties.class)
@ConditionalOnMissingBean(ResourceRepository.class)
public class ResourceRepositoryConfiguration {

@Bean
@ConditionalOnBean(SearchPathLocator.class)
public ResourceRepository resourceRepository(SearchPathLocator service) {
return new GenericResourceRepository(service);
}
}

返回ResourceRepository，其实现类为:GenericResourceRepository,内部服务为SearchPathLocator。实现方法为：

@Override
public synchronized Resource findOne(String application, String profile, String label,
String path) {
String[] locations = this.service.getLocations(application, profile, label).getLocations();
try {
for (int i = locations.length; i-- > 0;) {
String location = locations[i];
for (String local : getProfilePaths(profile, path)) {
Resource file = this.resourceLoader.getResource(location)
.createRelative(local);
if (file.exists() && file.isReadable()) {
return file;
}
}
}
}
catch (IOException e) {
throw new NoSuchResourceException(
"Error : " + path + ". (" + e.getMessage() + ")");
}
throw new NoSuchResourceException("Not found: " + path);
}

SearchPathLocator定义了搜索资源路径的策略，其层次结构如下：



2.EnvironmentRepositoryConfiguration

内部定了四种环境的配置

2.1. NativeEnvironmentRepository

@Configuration
@Profile("native")
protected static class NativeRepositoryConfiguration {

@Autowired
private ConfigurableEnvironment environment;

@Bean
public NativeEnvironmentRepository environmentRepository() {
return new NativeEnvironmentRepository(this.environment);
}

}

2.2. MultipleJGitEnvironmentRepository

@Configuration
@ConditionalOnMissingBean(EnvironmentRepository.class)
protected static class GitRepositoryConfiguration {

@Autowired
private ConfigurableEnvironment environment;

@Autowired
private ConfigServerProperties server;

@Bean
public MultipleJGitEnvironmentRepository environmentRepository() {
MultipleJGitEnvironmentRepository repository = new MultipleJGitEnvironmentRepository(this.environment);
if (this.server.getDefaultLabel()!=null) {
repository.setDefaultLabel(this.server.getDefaultLabel());
}
return repository;
}
}

2.3.SvnKitEnvironmentRepository

@Configuration
@Profile("subversion")
protected static class SvnRepositoryConfiguration {
@Autowired
private ConfigurableEnvironment environment;

@Autowired
private ConfigServerProperties server;

@Bean
public SvnKitEnvironmentRepository environmentRepository() {
SvnKitEnvironmentRepository repository = new SvnKitEnvironmentRepository(this.environment);
if (this.server.getDefaultLabel()!=null) {
repository.setDefaultLabel(this.server.getDefaultLabel());
}
return repository;
}
}

2.4.VaultEnvironmentRepository

@Configuration
@Profile("vault")
protected static class VaultConfiguration {
@Bean
public EnvironmentRepository environmentRepository(HttpServletRequest request, EnvironmentWatch watch) {
return new VaultEnvironmentRepository(request, watch, new RestTemplate());
}
}

另外还有，ConfigServerHealthIndicator、ConsulEnvironmentWatch、EnvironmentWatch

3.ConfigServerEncryptionConfiguration

定义了EncryptionController

@Bean
public EncryptionController encryptionController() {
EncryptionController controller = new EncryptionController(this.encryptor);
controller.setDefaultApplicationName(this.properties.getDefaultApplicationName());
controller.setDefaultProfile(this.properties.getDefaultProfile());
return controller;
}

4.ConfigServerMvcConfiguration

定义了EnvironmentController和ResourceController

@Bean
public EnvironmentController environmentController() {
EnvironmentController controller = new EnvironmentController(encrypted(), this.objectMapper);
controller.setStripDocumentFromYaml(this.server.isStripDocumentFromYaml());
return controller;
}

@Bean
@ConditionalOnBean(ResourceRepository.class)
public ResourceController resourceController(ResourceRepository repository) {
ResourceController controller = new ResourceController(repository,
encrypted());
return controller;
}

支持的协议有三种：

@Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
configurer.mediaType("properties", MediaType.valueOf("text/plain"));
configurer.mediaType("yml", MediaType.valueOf("text/yaml"));
configurer.mediaType("yaml", MediaType.valueOf("text/yaml"));
}