springboot配置文件外置處理

前言：

       在springboot項目中，一般的配置文件都在resource/config下面，它可以以兩種方式存在，一種是yml,一種是properties方式。

       當運維和開發分開的時候，比如連接mysql數據庫生產上的時候，運維不會告訴你賬戶和密碼，需要將配置文件放到固定的目錄下，運維自己去配置。這樣就需要配置文件外置。

當配置文件外置的時候，他是在項目啟動的時候，自己去加載配置文件。下面請看實現。

1. 需要增加一個文件

spring.factories，這個文件里面配置啟動的時候需要初始化的信息

org.springframework.boot.env.EnvironmentPostProcessor=cn.fintecher.pangolin.service.common.config.AutoConfigEnvironmentPostProcessor

2. 在AutoConfigEnvironmentPostProcessor這個類中增加如下代碼

package cn.fintecher.pangolin.service.common.config;

import cn.fintecher.pangolin.common.utils.AutoConfigEnvironmentUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.env.EnvironmentPostProcessor;
import org.springframework.boot.env.PropertySourceLoader;
import org.springframework.core.annotation.Order;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.core.io.support.SpringFactoriesLoader;

import java.util.List;

@Order(1)
public class AutoConfigEnvironmentPostProcessor implements EnvironmentPostProcessor {

    private final Logger logger = LoggerFactory.getLogger(AutoConfigEnvironmentPostProcessor.class);

    private final ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();

    private final List<PropertySourceLoader> propertySourceLoaders;

    public AutoConfigEnvironmentPostProcessor() {
        super();
        this.propertySourceLoaders = SpringFactoriesLoader.loadFactories(PropertySourceLoader.class, getClass().getClassLoader());
    }

    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        AutoConfigEnvironmentUtil.postProcessEnvironment(environment, application, propertySourceLoaders, resourcePatternResolver, logger);
    }

}

公共方法：

public static void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application,
                                   List<PropertySourceLoader> propertySourceLoaders, ResourcePatternResolver resourcePatternResolver,
                                   Logger logger) {

    String[] activeProfiles = environment.getActiveProfiles();
    for (String activeProfile : activeProfiles) {
        if (Objects.equals(activeProfile, "swagger"))
            continue;
        for (PropertySourceLoader loader : propertySourceLoaders) {
            for (String fileExtension : loader.getFileExtensions()) {
                if (!fileExtension.equals("yml"))
                    continue;

                String applicationLocal = ResourceUtils.CLASSPATH_URL_PREFIX + "/config/application.yml";
                try {
                    Resource applicationResource = resourcePatternResolver.getResource(applicationLocal);
                    List<PropertySource<?>> applactionYML = loader.load(ResourceUtils.CLASSPATH_URL_PREFIX + "/config/application.yml", applicationResource);
                    applactionYML.stream().forEach(environment.getPropertySources()::addLast);

                } catch (IOException e) {
                    e.printStackTrace();
                }

                String path = (String) environment.getPropertySources().get("applicationConfig: [classpath:/config/application.yml]").getProperty("spring.config.location");

                String location = path + "/application-" + activeProfile + "." + fileExtension;
                try {
                    Resource[] resources = resourcePatternResolver.getResources(location);
                    for (Resource resource : resources) {
                        List<PropertySource<?>> propertySources = loader.load(resource.getFilename(), resource);
                        if (null != propertySources && !propertySources.isEmpty()) {
                            propertySources.stream().forEach(environment.getPropertySources()::addLast);
                        }
                    }
                } catch (IOException e) {
                    logger.error(e.getMessage(), e);
                }
            }
        }
    }
}

3.  在代碼中獲取了spring.config.location這個配置文件，這個配置文件在application.yml中配置如下

spring:
  application:
    name: common-service
  config:
    location: @profile.properties@

@profile.properties@ 取的是pom文件中的

<profile.properties>file:d:/tomcat/profiles/${project.artifactId}/properties</profile.properties>

這樣這個配置文件就可以放在任何目錄下面。

4.  其他信息比如logger日志也需要放在外面，在application.yml增加如下配置即可。

ps: 不需要改動的配置信息都可以配置在application.yml中。

logging:
  config: @profile.properties@/logback-spring.xml

5. 可以試試。