spring中嵌套配置属性的前缀

Question

Spring boot 2.0.0.Relase

我有属性类：

@Configuration
@ConfigurationProperties(prefix="person")
public class PersonProperties {

    private AddressProperties addressProperties;

    public AddressProperties getAddressProperties() {
        return addressProperties;
    }

    public void setAddressProperties(final AddressProperties addressProperties) {
        this.addressProperties = addressProperties;
    }

    public static class AddressProperties {

        private String line1;

        public String getLine1() {
            return line1;
        }

        public void setLine1(final String line1) {
            this.line1 = line1;
        }
    }

}

和application.yml

person:
  address:
    line1: line1OfAddress

它没有正确绑定，因为我的AddressProperties对象是null。当一个类与yml属性AddressProperties -> Address同名时，它工作得很好。我尝试添加带有前缀address的Qualifier或ConfigurationProperties，但它不起作用。不幸的是，我在spring文档中找不到关于这个案例的有用信息。

如何为嵌套属性指定前缀？

Answer 1

yaml / Property文件中定义的属性应与class中定义的变量匹配。将yaml文件更改为

person:
  # addressProperties will also work here
  address-properties:
    line1: line1OfAddress

或者将bean定义为

@Configuration
@ConfigurationProperties(prefix = "person")
public class PersonProperties {

    // here variable name doesn't matter, it can be addressProperties as well
    // setter / getter should match with properties in yaml
    // i.e. getAddress() and setAddress()
    private AddressProperties address;

    public AddressProperties getAddress() {
        return address;
    }

    public void setAddress(AddressProperties address) {
        this.address = address;
    }
}

如果希望在address下获取所有属性，而不在单独的bean中定义它们，则可以将PersonProperties类定义为

@Configuration
@ConfigurationProperties(prefix = "person")
public class PersonProperties {

    private Map<String, Object> address;

    public Map<String, Object> getAddress() {
        return address;
    }

    public void setAddress(Map<String, Object> address) {
        this.address = address;
    }
}

这里的PersonProperties#address将包含{line1=line1OfAddress}

现在address下的所有属性都将位于Map中。

Answer 2

您可以简单地取消这两个类的嵌套，允许每个类都有自己的前缀。第一类：

@Configuration
@ConfigurationProperties(prefix="person")
public class PersonProperties {

    private AddressProperties addressProperties;

    public AddressProperties getAddressProperties() {
        return addressProperties;
    }

    public void setAddressProperties(final AddressProperties addressProperties) {
        this.addressProperties = addressProperties;
    }
}

第二类：

@Configuration
@ConfigurationProperties(prefix="person.address")
public class PersonAddressProperties {

    private String line1;

    public String getLine1() {
        return line1;
    }

    public void setLine1(final String line1) {
        this.line1 = line1;
    }
}

编辑:正如注释中所指出的，如果一段代码需要同时引用这两组属性，则必须同时注入这两个类。