@Value for property injection in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to inject the property value using @Value annotation.

Spring Boot

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class MyComponent {
    @Value("[1]")
    private String appName;
}

Drag options to blanks, or click blank then click option'

A"appName"

B"app.name"

C"${appName}"

D"${app.name}"

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to use ${} around the property key.

Using the variable name instead of the property key.

The @Value annotation requires the property key wrapped in ${} to inject the value from application properties.

2fill in blank

medium

Complete the code to inject a default value if the property is missing.

Spring Boot

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class Config {
    @Value("[1]")
    private String serverPort;
}

Drag options to blanks, or click blank then click option'

A"server.port:8080"

B"${server.port}"

C"${server.port:8080}"

D"server.port"

Attempts:

3 left

💡 Hint

Common Mistakes

Not including the default value syntax with colon.

Using quotes incorrectly around the property key.

Using ${property:default} syntax in @Value injects the property value or uses the default if missing.

3fill in blank

hard

Fix the error in the code to correctly inject an integer property value.

Spring Boot

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class ServerConfig {
    @Value("[1]")
    private int maxConnections;
}

Drag options to blanks, or click blank then click option'

A"${server.maxConnections}"

B"${server.maxConnections:100}"

C"server.maxConnections"

D"server.maxConnections:100"

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the ${} syntax.

Placing default value outside the ${}.

To inject an integer property with a default, use ${property:default} syntax inside @Value.

4fill in blank

hard

Fill both blanks to inject a list of strings from a comma-separated property.

Spring Boot

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import java.util.List;

@Component
public class ListConfig {
    @Value("[1]")
    private List<String> servers;

    public List<String> getServers() {
        return servers;
    }
}

Drag options to blanks, or click blank then click option'

A"${servers.list}"

B"${servers.list:}"

C"${servers.list.split(',')}"

D"${servers.list:localhost,127.0.0.1}"

Attempts:

3 left

💡 Hint

Common Mistakes

Not splitting the string to a list.

Missing default value for the property.

To inject a list from a comma-separated property, use ${property:default} and split it by comma.

5fill in blank

hard

Fill all three blanks to inject a nested property with default and convert it to uppercase.

Spring Boot

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class NestedConfig {
    @Value("[1]")
    private String env;

    public String getEnvUpper() {
        return env.[2]().[3]();
    }
}

Drag options to blanks, or click blank then click option'

A"${environment.name:dev}"

BtoLowerCase

CtoUpperCase

Dtrim

Attempts:

3 left

💡 Hint

Common Mistakes

Not using default value in @Value.

Calling methods in wrong order.

Inject the nested property with default, trim spaces, then convert to uppercase.