CODEWITHSUNDEEP
spring
TrongBang
TrongBang

Reputation: 967

Spring How to map list of custom pojo

In my application.yml file, I want to define a list of rules.

rules:
   - name: abc
     value: something
   - name: edf
     value: something

Then I want to define a service like this

@Service
public class MyService {
   public MyService(@Value("${rules}") List<Rule> rules) {
   }
}

For the Rule pojo, it's like this.

public class Rule {
   public String name, value;
}

Currently, I'm facing these errors.

  1. If I leave rules empty, it throws can't convert String to List<Rule>

    rules: []

  2. If I keep the values, it throws could not resolve placeholder 'rules'

I really don't know what I'm doing wrong here.

Upvotes: 0

Views: 42

Answers (1)

TrongBang
TrongBang

Reputation: 967

From Spring docs, I found this.

Using the @Value("${property}") annotation to inject configuration properties can sometimes be cumbersome, especially if you are working with multiple properties or your data is hierarchical in nature. Spring Boot provides an alternative method of working with properties that lets strongly typed beans govern and validate the configuration of your application

Link: https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html#boot-features-external-config-typesafe-configuration-properties

At the end, I have to introduce another class.

@Configuration
@ConfigurationProperties(prefix="rules")
public class Rules {
   public List<Rule> list;
}

Then I autowire it in MyService.

Upvotes: 1

Related Questions