@ConfigurationProperties for type-safe config in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enable binding of properties to the class.

Spring Boot

@[1]("app.settings")
public class AppSettings {
    private String name;

    public String getName() {
        return name;
    }

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

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AComponent

BConfigurationProperties

CService

DRepository

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Component instead of @ConfigurationProperties

Forgetting to specify the prefix in the annotation

The @ConfigurationProperties annotation binds external properties to this class using the specified prefix.

2fill in blank

medium

Complete the code to register the configuration properties class as a Spring bean.

Spring Boot

@Bean
public [1] appSettings() {
    return new AppSettings();
}

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AAppSettings

BComponent

CConfigurationProperties

DService

Attempts:

3 left

💡 Hint

Common Mistakes

Returning the annotation name instead of the class

Returning a Spring stereotype annotation instead of the class

The method returns an instance of the AppSettings class to register it as a bean.

3fill in blank

hard

Fix the error in the class to properly bind nested properties.

Spring Boot

public class DatabaseProperties {
    private String url;
    private Credentials [1];

    public static class Credentials {
        private String username;
        private String password;

        public String getUsername() {
            return username;
        }

        public void setUsername(String username) {
            this.username = username;
        }

        public String getPassword() {
            return password;
        }

        public void setPassword(String password) {
            this.password = password;
        }
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public Credentials getCredentials() {
        return credentials;
    }

    public void setCredentials(Credentials credentials) {
        this.credentials = credentials;
    }
}

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Acredentials

Bcredential

CCredentials

DcredentialInfo

Attempts:

3 left

💡 Hint

Common Mistakes

Using uppercase for the field name

Using a different name than the getter/setter methods

The field name must match the getter/setter and property name to bind nested properties correctly.

4fill in blank

hard

Fill both blanks to complete the annotation and enable validation.

Spring Boot

@[1]("server.config")
@[2]
public class ServerConfig {
    @NotNull
    private Integer port;

    public Integer getPort() {
        return port;
    }

    public void setPort(Integer port) {
        this.port = port;
    }
}

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AConfigurationProperties

BValidated

CComponent

DService

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting @Validated annotation

Using @Component instead of @ConfigurationProperties

Use @ConfigurationProperties to bind properties and @Validated to enable validation annotations like @NotNull.

5fill in blank

hard

Fill all three blanks to create a type-safe configuration with nested properties and validation.

Spring Boot

@[1]("mail.settings")
@[2]
public class MailSettings {
    private Smtp smtp;

    public static class Smtp {
        @NotEmpty
        private String host;

        @Min([3])
        private int port;

        public String getHost() {
            return host;
        }

        public void setHost(String host) {
            this.host = host;
        }

        public int getPort() {
            return port;
        }

        public void setPort(int port) {
            this.port = port;
        }
    }

    public Smtp getSmtp() {
        return smtp;
    }

    public void setSmtp(Smtp smtp) {
        this.smtp = smtp;
    }
}

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AConfigurationProperties

BValidated

C1

DComponent

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting @Validated annotation

Setting @Min to 0 or negative values

Using @Component instead of @ConfigurationProperties

Use @ConfigurationProperties to bind, @Validated to enable validation, and @Min(1) to ensure port is at least 1.