Spring @Value property for custom class

Question

Is it possible to use Spring\'s @Value annotation to read and write property values of a custom class type?

For example:

@Component
@PropertySource(\         


        

Answer 1

Spring can read properties and load them directly into a class.
Moreover, you can add @ConfigurationProperties(prefix = "data") on top of the class, instead of wiring each nested property one by one, by making the code cleaner.

Given all that, here is the final example with explanations:

// File: CustomerConfig.java
@Configuration
// Set property source file path (optional)
@PropertySource("classpath:/data.properties")
// Put prefix = "data" here so that Spring read properties under "data.*"
@ConfigurationProperties(prefix = "data") 
public class CustomerConfig {
    // Note: Property name here is the same as in the file (data.customer)
    // Spring will automatically read and put "data.customer.*" properties into this object
    private Customer customer; 

    // Other configs can be added here too... without wiring one-by-one

    public setCustomer(Customer customer){
        this.customer = customer;
    }

    public getCustomer(){
        return this.customer;
    }
}

That's it, now you have "data.customer.*" properties, loaded and accessible via CustomerConfig.getCustomer().

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To integrate it into your service (based on your example code):

// File: CustomerService.java
@Component
@PropertySource("classpath:/data.properties")
public class CustomerService {

    @Value("${data.isWaiting:#{false}}")
    private Boolean isWaiting;

    @Autowired // Inject configs, either with @Autowired or using constructor injection
    private CustomerConfig customerConfig;

    public void myMethod() {
        // Now its available for use
        System.out.println(customerConfig.getCustomer().toString());
    }
}

This way no "magical hack" is required to read configs into a class. Take a look at the @ConfigurationProperties documentation/examples, and this post for more useful info.

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Note: I'd suggest against using PropertyEditorSupport, since
a) it was built for different purpose, may change in future by breaking the code
b) it requires manual "handling" code inside => possible bugs
Instead, use what was built right for that purpose (Spring already has it), in order to both make the code easier to understand, and to gain possible inner improvements/optimizations which might be done in the future (or present).

Further improvements: Your CustomerService seems to be cluttered with configs (@PropertyService) too. I'd suggest reading those properties via another class too (similarly) then wiring that class here, instead of doing all in the CustomerService.