spring 读取配置文件的优先级

1 结论

在spring加载properties配置文件的过程中，会根据key出现覆盖现象，后加载的覆盖前面的。

| 加载顺序 | key | value | 最终输出 | | :---: | :--: | :--: | :--: | | p1 | testConver | 没有覆盖，为p1 | 覆盖，为p2属性 | | p1 | test| 测试区 | 测试区 | | p2 | testConver | 覆盖，为p2属性 | 覆盖，为p2属性 | | p2 | test| 开发区 | 开发区 |

2 上干活

2.1 java 代码

单元测试类为：

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(value = "classpath:/spring-resources.xml")
public class SpringPropertiesTest {@Value("${testConver}")private String testConver;@Value("${dev}")private String dev;@Value("${test}")private String test;@Testpublic void showPropValue() {System.out.println(testConver);System.out.println(dev);System.out.println(test);}
}

2.2 spring配置

spring-resources.xml配置为

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"><bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"><property name="order" value="1"/><property name="ignoreUnresolvablePlaceholders" value="true"/><property name="ignoreResourceNotFound" value="false"></property><property name="locations"><list><value>classpath:p1.properties</value><value>classpath:p2.properties</value></list></property></bean>
</beans>

2.3 配置文件

p1.properties：

testConver=没有覆盖，为p1
test=测试区

p2.properties：

testConver=覆盖，为p2属性
dev=开发区

2.4 控制台输出结果

控制台输出内容为：

十月 28, 2016 3:24:18 下午 org.springframework.test.context.TestContextManager retrieveTestExecutionListeners
信息: @TestExecutionListeners is not present for class [class com.dxhy.spring.SpringPropertiesTest]: using defaults.
十月 28, 2016 3:24:18 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring-resources.xml]
十月 28, 2016 3:24:19 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.GenericApplicationContext@2723a510: startup date [Fri Oct 28 15:24:19 CST 2016]; root of context hierarchy
十月 28, 2016 3:24:19 下午 org.springframework.core.io.support.PropertiesLoaderSupport loadProperties
信息: Loading properties file from class path resource [p1.properties]
十月 28, 2016 3:24:19 下午 org.springframework.core.io.support.PropertiesLoaderSupport loadProperties
信息: Loading properties file from class path resource [p2.properties]
十月 28, 2016 3:24:19 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@690a614: defining beans [propertyConfigurer,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.ConfigurationClassPostProcessor$ImportAwareBeanPostProcessor#0]; root of factory hierarchy
覆盖，为p2属性
开发区
测试区
十月 28, 2016 3:24:19 下午 org.springframework.context.support.AbstractApplicationContext doClose
信息: Closing org.springframework.context.support.GenericApplicationContext@2723a510: startup date [Fri Oct 28 15:24:19 CST 2016]; root of context hierarchy