How to convert mono object to object in java

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Converting Mono<Object> to Object in Java

In Java, if you have a Mono<Object> (Mono of a generic Object) and you want to extract the value wrapped in the Mono and convert it to a regular object, you can do so using the Mono’s inbuilt methods.

1. Using the block() Method

The easiest way to convert a Mono<Object> to a regular object is by using the block() method. The block() method blocks the current thread until the value is available, and returns the value as a regular object.

    
      Mono<Object> monoObject = ...; // Your Mono<Object> instance
      
      Object regularObject = monoObject.block();

It is important to note that the block() method should be used with caution, as it can potentially block the thread indefinitely if the Mono never completes.

2. Using the subscribe() Method

An alternative approach is to use the subscribe() method along with Java’s reactive programming features (e.g., using lambdas or custom implementations of Subscriber).

    
      Mono<Object> monoObject = ...; // Your Mono<Object> instance
      
      monoObject.subscribe(
        value -> {
          // Handle the value as a regular object
          // Do something with the value
        },
        error -> {
          // Handle any potential errors
          // Do something with the error
        }
      );

By subscribing to the Mono, you can handle the value as it becomes available through the value parameter in the lambda expression. You can also handle any errors that may occur through the error parameter.

Example

Here’s a complete example that demonstrates converting a Mono<Object> to a regular object:

    
      import reactor.core.publisher.Mono;
      
      public class MonoObjectConversionExample {
        
        public static void main(String[] args) {
          // Create a Mono<Object> with a value of "Hello, World!"
          Mono<Object> monoObject = Mono.just("Hello, World!");
          
          // Using the block() method
          Object regularObject = monoObject.block();
          System.out.println(regularObject); // Output: Hello, World!
          
          // Using the subscribe() method
          monoObject.subscribe(value -> System.out.println(value)); // Output: Hello, World!
        }
      }

In the example above, we create a Mono<Object> using the Mono.just() method with a value of “Hello, World!”. We then convert the Mono to a regular object using both the block() method and the subscribe() method.

Note: Make sure to include the necessary dependencies (e.g., Reactor Core) in your project to use the Mono class and reactive programming features.

By following the above steps, you can convert a Mono<Object> to a regular object in Java.

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