Solving the EntityNotFoundException Error in Spring Boot with Pagination

This guide addresses the common `EntityNotFoundException` error when implementing pagination in Spring Boot applications and provides actionable solutions to fix the issue.
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Understanding and Resolving EntityNotFoundException in Spring Boot with Pagination

The Problem: EntityNotFoundException

In your case, the error message reads:

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This signifies that the system is trying to load an Author entity with the ID 10000001, but it isn't present in the Author table of your database. This issue typically surfaces when there is a relationship defined between entities that isn't properly maintained or when trying to access related entities that don't exist.

Context of the Error

You mentioned that you are trying to implement pagination in your application, which is a good practice when dealing with large sets of data—something you certainly need given that you have over a million records. However, adding pagination could have highlighted existing issues in your data relationships and integrity.

Analyzing the Entity Relationship

You've defined two main entities: Book and Author. Here’s how they are connected:

Book Entity

[[See Video to Reveal this Text or Code Snippet]]

Author Entity

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The Book entity has a one-to-one relationship with the Author entity. If you have a Book that references an Author ID that does not exist in the Author table, this will throw the EntityNotFoundException when attempting to access the Book record through pagination.

Solution: Ensuring Data Integrity

To resolve the issue, follow these steps to ensure that your data relationships are correctly established:

1. Check the Author Table

Verify that the Author table contains an entry with the ID 10000001.

If this ID does not exist, consider adding it or ensure that your Book entries don't point to nonexistent authors.

2. Modify the Database

If necessary, clean up the books table to remove references to Author IDs that aren't valid. If using data entry or a batch import process, ensure that corresponding Author records are created before or along with Book records.

3. Implement Error Handling

Enhance your service layer to handle cases where an Author is not found gracefully. For example, you could return a user-friendly message or redirect the user to a relevant page.

4. Testing

After making changes, perform tests to ensure that pagination works as intended and retrieves valid data without throwing exceptions.

5. Logging

Utilize logging to capture when EntityNotFoundException occurs and what entity ID is being requested. This will help in diagnosing future issues swiftly.

Conclusion: Moving Forward

Addressing the EntityNotFoundException error requires a careful look at how your data is structured and ensuring all relationships are accounted for. By ensuring that your Author records exist for each Book and managing your database relationships correctly, you can enjoy seamless pagination and data handling in your Spring Boot application.

Final Words

Pagination is a powerful feature when dealing with large datasets, but it requires that underlying data integrity is maintained. By following the outlined steps, you can confiden