RPOP

Remove and return the last element (right side) of the list. If the list is empty or the key does not exist, return nil.

Redis Native Command Syntax

RPOP key

Parameter Description

• key: The key of the list

Detailed Explanation

The RPOP command is one of the list operation commands. It removes and returns the last element of the list. If the list is empty or the key does not exist, it returns nil.

Redisun Usage

In redisun, the RPOP command is implemented through the RPopCommand class and the rpop method in the Redisun class.

Basic Usage

Redisun redisun = Redisun.create(options -> {
  options.setAddress("redis://127.0.0.1:6379");
});

// Remove and get element from the tail of the list
String result = redisun.rpop("mylist");
if (result != null) {
  System.out.println("Popped element: " + result);
} else {
  System.out.println("List is empty or key does not exist");
}

// Asynchronous version
CompletableFuture<String> future = redisun.asyncRpop("mylist");
future.thenAccept(element -> {
  if (element != null) {
      System.out.println("Async popped element: " + element);
  } else {
      System.out.println("List is empty or key does not exist");
  }
});

Notes

1. If the list is empty or the key does not exist, return null
2. If the key exists but is not of list type, an exception will be thrown
3. The operation is atomic
4. In the blocking version of the BRPOP command, it will block and wait when the list is empty, but RPOP will not block

References

• Redis RPOP Command Official Documentation