Web 项目如何读取外部配置文件

素颜马尾好姑娘i 2023-10-12 12:25 9阅读 0赞

### 1. 用于启动时自动获取yml文件 ###

import java.io.File;
    
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.config.YamlPropertiesFactoryBean;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.env.EnvironmentPostProcessor;
    import org.springframework.core.env.ConfigurableEnvironment;
    import org.springframework.core.env.MutablePropertySources;
    import org.springframework.core.env.PropertiesPropertySource;
    import org.springframework.core.io.FileSystemResource;
    import org.springframework.stereotype.Component;
    
    @Component
    @Slf4j
    public class MyEnvironmentPostProcessor implements EnvironmentPostProcessor {
    
        private static final String mainYml = "application.yml";
    
        @Override
        public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
            String parent = System.getProperty("application.path");
            File parentFile = new File(parent);
            if(!parentFile.exists()){
                throw new NullPointerException("外部配置文件为空");
            }else {
                log.info("开始加载外部配置文件");
                File main = loadYml(parent);
                File active = loadMainYml(parent);
                YamlPropertiesFactoryBean mainYml = new YamlPropertiesFactoryBean();
                YamlPropertiesFactoryBean yaml = new YamlPropertiesFactoryBean();
                mainYml.setResources(new FileSystemResource(main));
                yaml.setResources(new FileSystemResource(active));
                MutablePropertySources propertySources = environment.getPropertySources();
                propertySources.addFirst(new PropertiesPropertySource(main.getName(), mainYml.getObject()));
                propertySources.addFirst(new PropertiesPropertySource(active.getName(), yaml.getObject()));
            }
        }
        public File loadYml(String parent){
            String main = parent + File.separator + mainYml;
            return new File(main);
        }
    
        public File loadMainYml(String parent){
            YamlPropertiesFactoryBean yaml = new YamlPropertiesFactoryBean();
            String main = parent + File.separator + mainYml;
            File mainFile = new File(main);
            if(mainFile.exists()){
                yaml.setResources(new FileSystemResource(mainFile));
                String active = yaml.getObject().getProperty("spring.profiles.active");
                String envFile = parent + File.separator + "application-" + active + ".yml";
                return new File(envFile);
            }
            return null;
        }
    }