Building Applications with Spring Data Redis - Spring Data - page 114

Second, we have to implement a persist() method that saves the contact
information. We can do this by performing the following steps:

1. If the contact ID is null, get a new ID and set the received Long object as an

ID of the Contact object.

2. Create a key for the contact.

3. Save the contact information as a string value.

We use value operations because we need to execute
only one operation.

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

private void persist(Contact persisted) {
Long id = persisted.getId();
if (id == null) {
id = contactIdCounter.incrementAndGet();
persisted.setId(id);
}
String key = buildKey(persisted.getId());
redisTemplate.opsForValue().set(key, persisted);
}

We are now ready to start implementing the CRUD operations for contacts. Let's
move on and find out how it is done.

Create
We can implement a method that adds new contacts by following these steps:

1. Save the added contact.

2. Add the contact information into the contact set.

3. Return the added contact.

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

@Override
public Contact add(Contact added) {
persist(added);
redisTemplate.opsForSet().add("contacts", added);
return added;
}