SpringBoot 读取配置文件的4种方式

配置文件

server:
  port: 8080
  servlet:
    context-path: /elasticsearch

spring:
  application:
    name: elasticsearch

1 使用@Value注解

在类中使用@Value注解来注入配置值

package com.xu.test;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class SpringBootTests {

	@Value("${spring.application.name}")
	private String name;

	@Test
	public void test() {
		System.out.println(name);
	}

}

elasticsearch

2 使用@ConfigurationProperties注解

创建一个Java Bean类，并使用@ConfigurationProperties注解指定配置文件的前缀，然后Spring Boot会自动将配置值注入到该Bean中。

package com.xu.test.conf;


import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

/**
 * @author hyacinth
 */
@Data
@Component
@ConfigurationProperties(prefix = "spring.redis")
public class MyConf {

    private String host;

    private String port;

    private String password;

    private String timeout;

}

package com.xu.test;

import cn.hutool.json.JSONUtil;
import com.xu.test.conf.MyConf;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class SpringBootTests {
	
    @Autowired
    private MyConf conf;

    @Test
    public void test() {
        System.out.println(JSONUtil.toJsonPrettyStr(conf));
    }

}

{
    "host": "127.0.0.1",
    "port": "6379",
    "password": null,
    "timeout": "10000"
}

3 使用Environment

package com.xu.test;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.core.env.Environment;

@SpringBootTest
class SpringBootTests {

    @Autowired
    private Environment env;

    @Test
    public void test() {
        System.out.println(env.getProperty("spring.application.name"));
    }

}

elasticsearch

4 使用@PropertySource注解

如果有其他的配置文件，需要在配置类上使用@PropertySource注解指定配置文件的路径，然后通过@Value注解或Environment接口来读取配置值（@PropertySource只支持properties文件）。

4.0 new.yml

test:
  name: "测试配置文件"

4.1 @PropertySource 支持 yml/yaml 文件

package com.xu.test.conf;

import cn.hutool.core.util.StrUtil;
import org.springframework.beans.factory.config.YamlPropertiesFactoryBean;
import org.springframework.core.env.PropertiesPropertySource;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.core.io.support.PropertySourceFactory;
import org.springframework.core.io.support.ResourcePropertySource;

import java.io.IOException;
import java.util.Properties;

/**
 * @author hyacinth
 */
public class YamlConfigFactory implements PropertySourceFactory {

    @Override
    public PropertySource<?> createPropertySource(String name, EncodedResource resource) throws IOException {
        name = (name != null) ? name : resource.getResource().getFilename();
        if (StrUtil.isBlank(name)) {
            throw new RuntimeException("配置文件不存在！");
        }
        if (!resource.getResource().exists()) {
            return new PropertiesPropertySource(name, new Properties());
        } else if (StrUtil.containsAnyIgnoreCase(name, ".yml", ".yaml")) {
            Properties yml = loadYml(resource);
            return new PropertiesPropertySource(name, yml);
        } else {
            return new ResourcePropertySource(name, resource);
        }
    }

    private Properties loadYml(EncodedResource resource) {
        YamlPropertiesFactoryBean factory = new YamlPropertiesFactoryBean();
        factory.setResources(resource.getResource());
        factory.afterPropertiesSet();
        return factory.getObject();
    }

}

4.2 使用@PropertySource注解

package com.xu.test.conf;


import lombok.Data;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.stereotype.Component;

/**
 * @author hyacinth
 */
@Data
@Component
@PropertySource(value = "classpath:new.yml", factory = YamlConfigFactory.class)
public class MyConf {

    @Value("${test.name}")
    private String name;

    @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }

}

package com.xu.test;

import cn.hutool.json.JSONUtil;
import com.xu.test.conf.MyConf;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class SpringBootTests {

    @Autowired
    private MyConf conf;

    @Test
    public void test() {
        System.out.println(JSONUtil.toJsonPrettyStr(conf));
    }

}

{
    "name": "测试配置文件"
}