The getter and setter that's used during configuration property binding varies when a getter or setter has been overridden to use a subclass of the property's type

[telxs]

Version: Spring Boot 2.5.7

Add BeanProperty from sub class first ，then ignore exist BeanProperty in super class (only use single parameter in BiConsumer)，and finally bind to the properties of the super class, resulting in the loss of the subclass property extension.

private void addProperties(Class<?> type) {
	while (type != null && !Object.class.equals(type)) {
		Method[] declaredMethods = getSorted(type, Class::getDeclaredMethods, Method::getName);
		Field[] declaredFields = getSorted(type, Class::getDeclaredFields, Field::getName);
		addProperties(declaredMethods, declaredFields);
		type = type.getSuperclass();
	}
}

private void addMethodIfPossible(Method method, String prefix, int parameterCount,
		BiConsumer<BeanProperty, Method> consumer) {
	if (method != null && method.getParameterCount() == parameterCount && method.getName().startsWith(prefix)
			&& method.getName().length() > prefix.length()) {
		String propertyName = Introspector.decapitalize(method.getName().substring(prefix.length()));
		consumer.accept(this.properties.computeIfAbsent(propertyName, this::getBeanProperty), method);
	}
}

void addSetter(Method setter) {
	if (this.setter == null || isBetterSetter(setter)) {
		this.setter = setter;
	}
}

[sbrannen]

@snicoll, this issue is referring to code in Spring Boot's JavaBeanBinder.

Can you provide details on why you think this should be addressed in Framework?

[wilkinsona]

Sorry, that's my fault. I got my binder classes mixed up. We'll transfer it back.

[wilkinsona]

@jiangbingi Thanks for the report. Unfortunately, I don't think I understand the problem that you've described. Here is an example of a sub-class overriding a property:

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;

import com.example.demo.Gh28917Application.ExtensionProperties;

@SpringBootApplication
@EnableConfigurationProperties(ExtensionProperties.class)
public class Gh28917Application {

	public static void main(String[] args) {
		SpringApplication.run(Gh28917Application.class, "--extension.example=test");
	}

	static class BaseProperties {
		
		private String example;

		public String getExample() {
			return example;
		}

		public void setExample(String example) {
			System.out.println("Base = " + example);
			this.example = example;
		}

	}
	
	@ConfigurationProperties("extension")
	static class ExtensionProperties extends BaseProperties {
		
		public void setExample(String example) {
			System.out.println("Extension = " + example);
		}
		
	}


}

Running the above outputs Extension = test.

Could you please provide a similar example that reproduces the problem you are seeing?

[telxs]

package test;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;

@EnableConfigurationProperties(TestApplication.ExtensionProperties.class)
@SpringBootApplication
public class TestApplication {

    public static void main(String[] args) {
        SpringApplication.run(TestApplication.class, "--extension.field.group=my-group", "--extension.field.tag=my-tag");
    }

    static class BaseProperties {

        private BaseField field;

        public BaseField getField() {
            return field;
        }

        public void setField(BaseField field) {
            this.field = field;
        }

        static class BaseField {

            private String group;

            public String getGroup() {
                return group;
            }

            public void setGroup(String group) {
                this.group = group;
            }
        }
    }

    @ConfigurationProperties(prefix = "extension")
    static class ExtensionProperties extends BaseProperties implements InitializingBean {

        private BaseFieldExt field;

        @Override
        public BaseFieldExt getField() {
            return field;
        }

        public void setField(BaseFieldExt field) {
            this.field = field;
        }

        static class BaseFieldExt extends BaseField {

            private String tag;

            public String getTag() {
                return tag;
            }

            public void setTag(String tag) {
                this.tag = tag;
            }
        }

        @Override
        public void afterPropertiesSet() throws Exception {
            if (field != null) {
                System.out.println("bind ExtensionProperties success:" + field.getGroup() + "," + field.getTag());
            } else if (super.getField() != null) {
                System.out.println("bind ExtensionProperties fail. super property is not null:" + super.getField().getGroup());
            }
        }
    }
}

[philwebb]

The binder is calling ExtensionProperties.setField(...) with a bound instance and ExtensionProperties.field is being set. You are calling super.getField() which is returning BaseProperties.field which has not been set. You probably want to update the setter in ExtensionProperties as follows:

public void setField(BaseFieldExt field) {
    this.field = field;
    super.setField(field);
}