多个属性文件问题

情境

文件路径如下：

├─src
│  ├─main
│  │  ├─java
│  │  │  └─com
│  │  │      └─ryo
│  │  │          └─spring
│  │  │              └─property
│  │  │                      User.java
│  │  │
│  │  └─resources
│  │          one.properties
│  │          spring-beans-one.xml
│  │          spring-beans-two.xml
│  │          two.properties
│  │
│  └─test
│      └─java
│              UserTest.java

one.properties

oneName=one

two.properties

twoName=two

spring-beans-one.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">


    <context:property-placeholder location="classpath*:one.properties"/>

    <bean name="one" class="com.ryo.spring.property.User">
        <property name="name" value="${oneName}"/>
    </bean>

</beans>

spring-beans-two.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <context:property-placeholder location="classpath*:two.properties"/>

    <bean name="two" class="com.ryo.spring.property.User">
        <property name="name" value="${twoName}"/>
    </bean>

</beans>

User.java

public class User {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

UserTest.java

测试代码

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {
        "classpath:spring-beans-one.xml",
        "classpath:spring-beans-two.xml",
})
public class UserTest {

    @Autowired
    @Qualifier("one")
    private User one;

    @Autowired
    @Qualifier("two")
    private User two;

    @Test
    public void infoTest() {
        System.out.println(one.getName());
        System.out.println(two.getName());
    }
}

Error

运行测试案例，报错如下：

...
Caused by: org.springframework.beans.factory.BeanDefinitionStoreException: Invalid bean definition with name 'two' defined 
in class path resource [spring-beans-two.xml]: Could not resolve placeholder 'twoName' in string value "${twoName}"; 
nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'twoName' in string value "${twoName}"
...

原因

[关于的一个有趣现象](http://www.iteye.com/topic/1131688)

Spring导入多个独立的 .properties配置文件

解决方案

一、ignore-unresolvable

引入属性文件时，指定 ignore-unresolvable="true"。注意：所有的属性文件引入都需要显示指定。

如：

<context:property-placeholder location="classpath*:one.properties" ignore-unresolvable="true"/>

二、同时引入多个属性文件

属性文件不要在单个文件一个个引入。直接在最后统一引入。可使用如下方式： (支持 RegEx 匹配，只需要在一个文件中引入即可，其他文件移除。)

<!-- 加载所有配置文件 -->
<context:property-placeholder location="classpath*:*.properties"/>

也可以采用下面的方式(二者本质是等价的)

<bean id="propertyPlaceholderConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">
        <list>
            <!-- 这里支持多种寻址方式：classpath和file -->
            <value>classpath:one.properties</value>
            <value>classpath:two.properties</value>
            <!-- 推荐使用file的方式引入，这样可以将配置和代码分离 -->
            <!--<value>file:/opt/demo/config/demo-remote.properties</value>-->
        </list>
    </property>
</bean>

解析 properties 文件

一、直接注入到bean中

二、使用 @Value

UserTest.java

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {
        "classpath:spring-beans-one.xml",
        "classpath:spring-beans-two.xml",
})
public class UserTest {

    @Value("${oneName}")
    private String oneName;

    @Test
    public void oneNameTest() {
        System.out.println(oneName);
    }
}