Cache key strategies in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify a cache key using Spring's @Cacheable annotation.

Spring Boot

@Cacheable(value = "users", key = "#[1]")
public User getUserById(Long id) {
    // method body
}

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

Avalue

BuserId

Ckey

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Using a parameter name that does not exist in the method signature.

Omitting the # prefix in the key expression.

The cache key is set to the method parameter id using #id in the SpEL expression.

2fill in blank

medium

Complete the code to create a cache key based on multiple method parameters.

Spring Boot

@Cacheable(value = "products", key = "#[1] + '-' + #[2]")
public Product getProduct(String category, Long productId) {
    // method body
}

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

Acategory

BproductId

Cid

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect parameter names that don't match the method signature.

Not concatenating parameters properly in the key expression.

The first part of the key uses the category parameter, combined with the productId parameter.

3fill in blank

hard

Fix the error in the cache key expression to correctly use the method parameter.

Spring Boot

@Cacheable(value = "orders", key = "#[1]")
public Order findOrder(Long orderId) {
    // method body
}

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

Aid

BorderId

Corder

DorderID

Attempts:

3 left

💡 Hint

Common Mistakes

Using a parameter name with incorrect case.

Using a parameter name that does not exist.

The method parameter is named orderId, so the key expression must use #orderId.

4fill in blank

hard

Fill both blanks to create a cache key using two parameters separated by an underscore.

Spring Boot

@Cacheable(value = "sessions", key = "#[1] + '_' + #[2]")
public Session getSession(String userId, String sessionId) {
    // method body
}

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

AuserId

BsessionId

Cid

Dtoken

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect parameter names.

Forgetting to add quotes around the underscore.

The cache key combines userId and sessionId separated by an underscore.

5fill in blank

hard

Fill all three blanks to create a cache key using a method parameter and a method call on it.

Spring Boot

@Cacheable(value = "employees", key = "#[1] + '-' + #[2].[3]()")
public Employee getEmployee(EmployeeId empId) {
    // method body
}

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

AempId

CtoString

DgetId

Attempts:

3 left

💡 Hint

Common Mistakes

Using different parameter names in blanks 1 and 2.

Using a method name that does not exist on the parameter.

The cache key uses the empId parameter and calls its toString() method.