Springboot annotation @value always reported could not resolve placeholder problem

Scene:

Two configuration files: db.properties,application.properties

Referencing db.properties in the database configuration

class= "..." >        <property name= "Locations" >            <list>                <value>classpath*:/ db.properties</value>                <value>file:/etc/db.properties</value>            </list>        </ Property>    </bean>

At this time, application.properties inside the property will not be loaded into the, if you use @value, will be reported could not resolve placeholder

@Controller  Public class Firstcontroller {        @Value ("${welcome.message}")    private  String test;    @RequestMapping ("/GETW")    public String Welcome (map<string, object>  Model) {        //model.put ("message", this.message);         System.out.println (test);         return "My";    }}

Such use will be reported could not resolve placeholder

Solve:

Put the contents of the db.properties into the application.properties, and then cite this side:

class= "..." >        <property name= "Locations" >            <list>                <value>classpath*:/ application.properties</value>                <value>file:/etc/application.properties</value>            </ list>        </property>    </bean>

Or two of files are loaded

class= "..." >        <property name= "Locations" >            <list>                <value>classpath* :/application.properties</value>                <value>classpath*:/db.properties</value>                < value>file:/etc/application.properties</value>            </list>        </property>    </ Bean>

The reason is spring's loading mechanism: the spring container uses the discovery mechanism of reflection scanning, A bean that detects a org.springframework.beans.factory.config.PropertyPlaceholderConfigurer in the spring container stops the remaining propertyplaceholderconf Igurer Scan (Spring 3.1 already uses propertysourcesplaceholderconfigurer instead of propertyplaceholderconfigurer), so depending on the order of loading, The second property-placeholder configured is not loaded by spring, so the placeholder is not parsed when you use @value injection

Springboot annotation @value always reported could not resolve placeholder problem