Spring can't resolve property placeholder but still supplies the value? - spring

Question

Currently working on a Spring application; I'm very new to Spring.
For some reason, Spring picks up my .properties file and injects the literal into my object. In the output, I see the appropriate line: com.test.Baseball#345e5a17 with the name "Chuck Norris". However, later in the stacktrace, it says that this value cannot be resolved:
com.test.Baseball#345e5a17 with the name "Chuck Norris"
14:58:39.618 [main] DEBUG org.springframework.context.support.ClassPathXmlApplicationContext -
Closing org.springframework.context.support.ClassPathXmlApplicationContext#e2d56bf, started on Mon
Dec 16 14:58:36 CST 2019
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.2.2.RELEASE)
2019-12-16 14:58:39.976 INFO 98376 --- [ main] .c.t.SpringAnnotationsProjectApplication :
Starting SpringAnnotationsProjectApplication on C001823506 with PID 98376 (C:\Users\\eclipse-
workspace\Spring-Annotations-project\target\classes started by in C:\Users\\eclipse-
workspace\Spring-Annotations-project)
2019-12-16 14:58:39.981 INFO 98376 --- [ main] .c.t.SpringAnnotationsProjectApplication :
No active profile set, falling back to default profiles: default
2019-12-16 14:58:40.878 INFO 98376 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer :
Tomcat initialized with port(s): 8080 (http)
2019-12-16 14:58:40.897 INFO 98376 --- [ main] o.apache.catalina.core.StandardService :
Starting service [Tomcat]
2019-12-16 14:58:40.898 INFO 98376 --- [ main] org.apache.catalina.core.StandardEngine :
Starting Servlet engine: [Apache Tomcat/9.0.29]
2019-12-16 14:58:41.126 INFO 98376 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] :
Initializing Spring embedded WebApplicationContext
2019-12-16 14:58:41.134 INFO 98376 --- [ main] o.s.web.context.ContextLoader :
Root WebApplicationContext: initialization completed in 1136 ms
2019-12-16 14:58:41.217 WARN 98376 --- [ main] ConfigServletWebServerApplicationContext :
Exception encountered during context initialization - cancelling refresh attempt:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'coach':
Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException:
Could not resolve placeholder 'coach.name' in value "${coach.name}"
2019-12-16 14:58:41.225 INFO 98376 --- [ main] o.apache.catalina.core.StandardService :
Stopping service [Tomcat]
2019-12-16 14:58:41.237 INFO 98376 --- [ main] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with
'debug' enabled.
2019-12-16 14:58:41.247 ERROR 98376 --- [ main] o.s.boot.SpringApplication :
Application run failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'coach':
Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException:
Could not resolve placeholder 'coach.name' in value "${coach.name}"
at
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:405) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:879) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) ~[spring-context-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.2.RELEASE.jar:2.2.2.RELEASE]
at com.cat.test.SpringAnnotationsProjectApplication.main(SpringAnnotationsProjectApplication.java:20) [classes/:na]
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'coach.name' in value "${coach.name}"
The .properties file:
coach.name="Chuck Norris"
coach.item="basketball"
The applicationContext.xml file:
<?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:component-scan base-package="com.test"></context:component-scan>
<context:property-placeholder location="classpath:PropertyValues.properties"/>
</beans>
The Coach class (the problem class):
package com.test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
#Component
public class Coach {
private SportsItem item;
#Value("${coach.name}")
private String name;
#Autowired
public Coach(#Qualifier("baseball") SportsItem item) {
this.item = item;
}
public void setItem(SportsItem item) {
this.item = item;
}
public SportsItem getItem() {
return item;
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
}
my main class:
#SpringBootApplication
public class SpringAnnotationsProjectApplication {
public static void main(String[] args) {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
Coach coachBean = context.getBean("coach", Coach.class);
System.out.println(coachBean.getItem() + " with the name " + coachBean.getName());
context.close();
SpringApplication.run(SpringAnnotationsProjectApplication.class, args);
}
}
What makes this strange is that in the very first line, we get the proper output. Despite this, Spring still detects a problem and shuts down.
What is going on here?

Answer 1

The reason you are seeing these errors is because you need to import the applicationContext.xml. You can do this by creating a configuration class that imports the resource. This is explained in this document: https://www.springboottutorial.com/spring-boot-java-xml-context-configuration. I have also included an example of what it would look like below.
#Configuration
#ImportResource({"classpath*:applicationContext.xml"})
public class XmlConfiguration
{
}