StandardEnvironment

org.springframework.core.env.StandardEnvironment


public class StandardEnvironment extends AbstractEnvironment 

public abstract class AbstractEnvironment implements ConfigurableEnvironment 

public interface ConfigurableEnvironment extends Environment, ConfigurablePropertyResolver 


配置读取顺序，跟添加顺序有关系
MutablePropertySources  
addFirst  addLast  注意区别

使用 addLast 加载自定义配置
StandardEnvironment {activeProfiles=[], defaultProfiles=[default], propertySources=[MapPropertySource {name='systemProperties'}, SystemEnvironmentPropertySource {name='systemEnvironment'}, PropertiesPropertySource {name='PropertiesPropertySource1'}, PropertiesPropertySource {name='PropertiesPropertySource2'}]}

propertySources=[MapPropertySource {name='systemProperties'}, SystemEnvironmentPropertySource {name='systemEnvironment'}, PropertiesPropertySource {name='PropertiesPropertySource1'}, PropertiesPropertySource {name='PropertiesPropertySource2'}
 
 
MapPropertySource {name='systemProperties'}
SystemEnvironmentPropertySource {name='systemEnvironment'}
PropertiesPropertySource {name='PropertiesPropertySource1'}
PropertiesPropertySource {name='PropertiesPropertySource2'}

按顺序读取 propertySources 中的配置


env.getSystemEnvironment()  环境变量
env.getSystemProperties()   jvm系统参数



StandardEnvironment
protected void customizePropertySources(MutablePropertySources propertySources) {
    propertySources.addLast(new MapPropertySource(SYSTEM_PROPERTIES_PROPERTY_SOURCE_NAME, getSystemProperties()));
    propertySources.addLast(new SystemEnvironmentPropertySource(SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME, getSystemEnvironment()));
}

System.getProperties()
System.getenv()



例子代码


		
import java.util.Properties;

import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertiesPropertySource;
import org.springframework.core.env.StandardEnvironment;

public class EnvTest {
	
	public static void main(String[] args) throws Exception {			
		StandardEnvironment env = new StandardEnvironment();
		
		System.out.println(env);
		System.out.println(env.getDefaultProfiles());
		System.out.println(env.getSystemEnvironment());
		System.out.println(env.getSystemProperties());
		MutablePropertySources mutablePropertySources = env.getPropertySources();
				
		Properties  properties1 = new Properties();
		properties1.put("name", "cat1");
		
		Properties  properties2 = new Properties();
		properties2.put("name", "cat2");
		
		PropertiesPropertySource pps1 = new PropertiesPropertySource("PropertiesPropertySource1",properties1);
		PropertiesPropertySource pps2 = new PropertiesPropertySource("PropertiesPropertySource2",properties2);
	
		// mutablePropertySources.addFirst(pps1);
		// mutablePropertySources.addFirst(pps2);
		
		mutablePropertySources.addLast(pps1);
		mutablePropertySources.addLast(pps2);
		
		System.out.println(env);
		
		// addFirst
		// StandardEnvironment {activeProfiles=[], defaultProfiles=[default], propertySources=[PropertiesPropertySource {name='PropertiesPropertySource2'}, PropertiesPropertySource {name='PropertiesPropertySource1'}, MapPropertySource {name='systemProperties'}, SystemEnvironmentPropertySource {name='systemEnvironment'}]}

		// addLast  注意顺序
		// StandardEnvironment {activeProfiles=[], defaultProfiles=[default], propertySources=[MapPropertySource {name='systemProperties'}, SystemEnvironmentPropertySource {name='systemEnvironment'}, PropertiesPropertySource {name='PropertiesPropertySource1'}, PropertiesPropertySource {name='PropertiesPropertySource2'}]}
	
		System.out.println(env.getSystemEnvironment().get("name"));
		// -Dname=name-in-jvm-args
		System.out.println(env.getSystemProperties().get("name"));
		System.out.println(env.getProperty("name"));	
	}
}
		

完整代码
https://gitee.com/dyyx/springboothello/blob/master/src/test/java/dyyx/EnvTest.java
		


 System.getenv 与 System.getProperty 的区别