Building Applications with Spring Data Redis - Spring Data - page 115

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Our application has two views that present contact information: the first one shows a
list of contacts and the second one shows the information of a single contact.

First, we have to implement a method that fetches all the contacts from Redis. We
can implement the findAll() method by following these steps:

1. Fetch all the contacts from the contact set.

2. Create a new ArrayList object and return the created object.

The source code of the findAll() method is given as follows:

@Override
public List<Contact> findAll() {
Collection<Contact> contacts = redisTemplate.opsForSet().
members("contacts");
return new ArrayList<Contact>(contacts);
}

Second, we have to implement a method that returns the information of a single
contact. Our implementation of the findById() method includes the following steps:

1. Create the key of the contact.

2. Get the Contact object from Redis.

3. If no contact is found, throw NotFoundException .

4. Return the found object.

The source code of the findById() method is given as follows:

@Override
public Contact findById(Long id) throws NotFoundException {
String key = buildKey(id);
Contact found = redisTemplate.opsForValue().get(key);

if (found == null) {
throw new NotFoundException("No contact found with id: {}" +
id);
}

return found;
}