Service class to read data from yml file - spring

Question

I have following code:
application.yml
security:
section1:
key1: "value1"
key2: "value2"
section2:
key1: "value1"
key2: "value2"
//Main class
#SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
Service class
#Service
public class DemoService {
private Map<String,Section1Properties>projects=new HashMap<String,Section1Properties>();
#Autowired
public DemoService(SecurityProperties security) {
this.projects=security.myConfig1();
projects.get("section1").getKey1();
projects.get("section1").getKey2();
}
}
Configuration Class
#Configuration
#EnableConfigurationProperties
#ConfigurationProperties(prefix = "security")
public class SecurityProperties implements Serializable{
private static final long serialVersionUID = 1L;
private String section1;
private String section2;
private Map<String,Section1Properties> sec1=new HashMap<String,Section1Properties>();
private Map<String,Section2Properties> sec2=new HashMap<String,Section2Properties>();
public Map<String,Section1Properties> myConfig1(){
return sec1;
}
public Map<String,Section2Properties> myConfig2(){
return sec2;
}
public String getSection1() {
return section1;
}
public void setSection1(String section1) {
this.section1 = section1;
}
public String getSection2() {
return section2;
}
public void setSection2(String section2) {
this.section2 = section2;
}
public static class Section1Properties{
private String key1;
private String key2;
public String getKey1() {
return key1;
}
public void setKey1(String key1) {
this.key1 = key1;
}
public String getKey2() {
return key2;
}
public void setKey2(String key2) {
this.key2 = key2;
}
}
public static class Section2Properties{
private String key1;
private String key2;
public String getKey1() {
return key1;
}
public void setKey1(String key1) {
this.key1 = key1;
}
public String getKey2() {
return key2;
}
public void setKey2(String key2) {
this.key2 = key2;
}
}
}
when I am running this code I am getting error like below.
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'demoService' defined in file [C:\Users\ABC\eclipse-workspace\demo\target\classes\com\demo\DemoService.class]: Bean instantiation via constructor failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.demo.DemoService]: Constructor threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:314) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:295) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1358) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1204) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[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.demo.DemoApplication.main(DemoApplication.java:10) [classes/:na]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.demo.DemoService]: Constructor threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:213) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:117) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:310) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
... 19 common frames omitted
Caused by: java.lang.NullPointerException: null
at com.demo.DemoService.(DemoService.java:18) ~[classes/:na]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_231]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_231]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_231]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_231]
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:200) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]
... 21 common frames omitted