Spring Boot Yaml配置：类型化属性列表

Question

I'm following the 24.8.3 Merging Complex Types section of Spring Boot's 24. Externalized Configuration documentation. I have this config.yaml file:

acme:
  list:
    - name: my name
      description: my description
    - name: another name
      description: another description

The Properties file looks like this:

@ConfigurationProperties("acme")
@YamlPropertySource(value = { "classpath:/config.yaml" })
public class AcmeProperties {

    private final List<MyPojo> list = new ArrayList<>();

    public List<MyPojo> getList() {
        return this.list;
    }
}

The MyPojo class:

public class MyPojo {
    private String name;
    private String description;

    public MyPojo(String name, String description) {
        this.name = name;
        this.description = description;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}

The test, which fails, looks like this:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { AcmeProperties.class })
public class AcmePropertiesTest {

    @Autowired
    private AcmeProperties properties;

    @Test
    public void getOpScoringClusters() {
        Assert.assertEquals(2, properties.getList().size()); // FAIL!
    }
}

Spring Boot version 1.5.6.

Basically I want to have a list of typed properties. What am I doing wrong?

Answer 1

Several comments have highlighted multiple issues with the code presented.

Firstly, the fields inside a configuration properties can't be final as spring uses the setter to set the value. Secondly, @YamlPropertySource is not something provided by spring so won't do anything in this context. Thirdly, even if you did use the spring PropertySource annotation, unfortunately you can't use it with yaml files.

YAML files cannot be loaded by using the @PropertySource annotation.

I've created a sample project that uses the code you presented and has been modified so that it passes the unit test. It's using spring boot 2.x instead of 1.x but the only significant difference should be the annotations used in the test class.

https://github.com/michaelmcfadyen/spring-boot-config-props-demo