SpringBoot读取application.properties配置文件

方案1：

使用PropertiesLoaderUtils

import java.util.Properties;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.PropertiesLoaderUtils;

public static Properties readPropertiesFile(String fileName) {
    try {
        Resource resource = new ClassPathResource(fileName);
        Properties props = PropertiesLoaderUtils.loadProperties(resource);
        return props;
    } catch (Exception e) {
        System.out.println("读取配置文件：" + fileName + "异常，读取失败");
        e.printStackTrace();
    }
    return null;
}

Properties properties = readPropertiesFile("application.properties");
System.out.println(properties.getProperty("spring.rabbitmq.host"));

方案2：

使用Environment

import org.springframework.core.env.Environment;

@Autowired
private Environment environment;

System.out.println(environment.getProperty("spring.rabbitmq.host"));

方案3：

使用@Value

import org.springframework.beans.factory.annotation.Value;

@Value("${spring.rabbitmq.host}")
private String rabbitmqHost;

System.out.println(rabbitmqHost);

方案4：

使用@ConfigurationProperties

属性类

import lombok.Getter;
import lombok.Setter;
import org.springframework.boot.context.properties.ConfigurationProperties;

@Getter
@Setter
@ConfigurationProperties(prefix = "spring.rabbitmq")
public class TestProperties {
    private String host;
    private String port;
    private String username;
    private String password;
}

注册属性配置类

import org.springframework.boot.SpringBootConfiguration;
import org.springframework.boot.context.properties.EnableConfigurationProperties;

@EnableConfigurationProperties(TestProperties.class)
@SpringBootConfiguration
public class TestConfiguration {
}

使用配置类

@Autowired
private TestProperties testProperties;

System.out.println(testProperties.getHost());