Spring Boot中读取配置文件的5种方式汇总(最新整理)

app:
  name: demo-app
  port: 8080
  desc: ${app.name}-${app.port}  # SpEL 拼接

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component
public class AppConfig {
    // 直接绑定单个属性
    @Value("${app.name}")
    private String appName;
    // 绑定并设置默认值（配置不存在时使用）
    @Value("${app.version:1.0.0}")
    private String appVersion;
    // 绑定 SpEL 拼接的属性
    @Value("${app.desc}")
    private String appDesc;
}

app:
  name: demo-app
  port: 8080
  database:
    url: jdbc:mysql://localhost:3306/test
    username: root
    password: 123456
  servers:
    - 192.168.1.1
    - 192.168.1.2

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import java.util.List;
// 前缀指定配置分组，需配合 @Component 或 @EnableConfigurationProperties 生效
@Component
@ConfigurationProperties(prefix = "app")
public class AppProperties {
    private String name;
    private Integer port;
    private Database database; // 嵌套对象
    private List<String> servers; // 集合
    // 嵌套类
    public static class Database {
        private String url;
        private String username;
        private String password;
        // getter/setter
    }
    // 必须提供 getter/setter（Spring 反射赋值）
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    // 其他字段的 getter/setter
}

import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Configuration;
@Configuration
@EnableConfigurationProperties(AppProperties.class)
public class Config {
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;
@Component
public class EnvConfig {
    @Autowired
    private Environment env;
    public void getConfig() {
        // 读取单个配置
        String appName = env.getProperty("app.name");
        // 读取并指定默认值
        Integer appPort = env.getProperty("app.port", Integer.class, 8080);
        // 读取嵌套配置
        String dbUrl = env.getProperty("app.database.url");
    }
}

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
public class ManualPropertiesReader {
    public static void main(String[] args) throws IOException {
        Properties props = new Properties();
        // 加载 classpath 下的配置文件
        try (InputStream is = ManualPropertiesReader.class.getClassLoader().getResourceAsStream("application.properties")) {
            props.load(is);
            String appName = props.getProperty("app.name");
        }
    }
}

<!-- pom.xml 引入依赖 -->
<dependency>
    <groupId>org.yaml</groupId>
    <artifactId>snakeyaml</artifactId>
</dependency>

import org.yaml.snakeyaml.Yaml;
import java.io.InputStream;
import java.util.Map;
public class ManualYmlReader {
    public static void main(String[] args) {
        Yaml yaml = new Yaml();
        try (InputStream is = ManualYmlReader.class.getClassLoader().getResourceAsStream("application.yml")) {
            Map<String, Object> data = yaml.load(is);
            // 读取嵌套配置
            Map<String, Object> app = (Map<String, Object>) data.get("app");
            String appName = (String) app.get("name");
        }
    }
}

custom.name=my-custom-app
custom.age=20

import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;
import org.springframework.beans.factory.annotation.Value;
@Component
// 加载自定义 properties 文件（仅支持 properties，不直接支持 yml）
@PropertySource("classpath:custom.properties")
public class CustomConfig {
    @Value("${custom.name}")
    private String customName;
}

import org.springframework.core.env.MapPropertySource;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.core.io.support.PropertySourceFactory;
import org.yaml.snakeyaml.Yaml;
import java.util.Map;
public class YmlPropertySourceFactory implements PropertySourceFactory {
    @Override
    public org.springframework.core.env.PropertySource<?> createPropertySource(String name, EncodedResource resource) {
        Yaml yaml = new Yaml();
        Map<String, Object> data = yaml.load(resource.getInputStream());
        return new MapPropertySource(resource.getResource().getFilename(), data);
    }
}

@PropertySource(value = "classpath:custom.yml", factory = YmlPropertySourceFactory.class)
@Component
public class CustomYmlConfig {
    @Value("${custom.name}")
    private String customName;
}