Loading Spring-boot properties to POJO

Question

I have properties like this:

credentials:
   userid: <userid>
   password: <password>

I have a POJO:

@Setter
public class Credentials {
   private String userid;
   private String password;

However, this POJO is in another jar, so I can't add annotations. So I thought I'd try something like this:

@Configuration
@Getter
@Setter
@ConfigurationProperties("credentials")
public class MyCredentials {
   private Credentials credentials = new Credentials();
}

But I can't get my class to load the properties. How can I get it to work in this scenario?

Why do you want to load your credential properties into the Credentials POJO? You dont need the Credentials pojo to access values from your properties files. — Abdullah Khan, Feb 01 '22 at 03:39

bhaskarkh · Answer 1 · 2022-02-01T03:37:58.377

Just make a separate configuration bean and access value from that try below code

@Configuration
@Getter
@Setter
@ConfigurationProperties("credentials")
public class MyCredentialSetting{

private String userid;
private String password;

}

Now wherever you want to use just use @Autowired like in controller or service

Here myCredentialSetting has value from propertoes file injected by spring boot automatically

@Autowired
private MyCredentialSetting myCredentialSetting;

String userIdValue=myCredentialSetting.getUserid(); //you will get user id value by this
String password=myCredentialSetting.getPassword();

//Setting value to original pojo for furthur use

private Credentials credentials = new Credentials();
credentials.setUserid(userIdValue);
credentials.setPassword(password);

But my point is that the POJO already exists elsewhere, so I don't want to have to re-create it as you've done here with `MyCredentialSetting` — Peter Kronenberg, Feb 01 '22 at 14:39

Juan · Answer 2 · 2022-02-02T00:59:20.237

-1

You are mixing things.

@Setter (and @Getter) are most likely lombok project annotations. These annotations at compile time will generate the getX() and setX() methods on a Pojo with a property "x".

If the Credentials POJO is in another jar, it should have a getter and setter (or it is not a POJO). So we don't care about lombok.

On another side you have a @Configuration class where Spring boot will create the different beans of your application.

The class should look something like this:

@Configuration
@ConfigurationProperties("credentials")
public class MyCredentials {

   @Bean("credentials")
   public Credentials credentials(
       @Value("${credentials.userid}") String userid,
       @Value("${credentials.password}") String password) {
         Credentials credentials = new Credentials();
         credentials.setUserid(userid);
         credentials.setPassword(password):
         return credentials;
   }

}

With the @Value annotation Spring boot will inject the properties into the method that will create the bean.

EDIT I

As stated by @M.Deinum, the same can be obtained by:

@Configuration
public class MyCredentials {

   @Bean("credentials")
   @ConfigurationProperties("credentials")
   public Credentials credentials() {
         return new Credentials();
   }
}

@ConfigurationProperties will find the properties prefixed with "credentials" and inject them into the credentials bean.

Thanks for the tip @M.Deinum!

edited Feb 02 '22 at 00:59

answered Feb 01 '22 at 03:46

Juan

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You can just put the `@ConfigurationProperties` on the `@Bean` method and return just `new Credentials()` from the `@Bean` method. Spring Boot will do the binding afterwards. – M. Deinum Feb 01 '22 at 07:48
Not mixing things. The Lombok annotations were just to show that there are Getters and Setters. But you are using the `@Value` annotation. Not sure it makes sense to use that with `@ConfigurationProperties`. `@Value` is for injecting individual properties. `@ConfigurationProperties` is for injecting an entire structure, indicated by the prefix – Peter Kronenberg Feb 01 '22 at 14:42
@PeterKronenberg The '@Getter' and '@Setter' will just create a getCredentials() and setCredentials(Credentials credentials) methods inside MyCredentials class wihich is a '@Configuration' file (A more clear name would be MyCredentialsConf). The solution I wrote will create a Credentials bean with the values set. Perhaps you want something different which is not clear in the question. – Juan Feb 01 '22 at 16:17
You don’t need `ConfigurationProperties` on the class. – Abhijit Sarkar Feb 02 '22 at 00:57
Copy paste issue :) – Juan Feb 02 '22 at 00:58

Loading Spring-boot properties to POJO

2 Answers2