Inspecting the output directory programmatically

Oct 13, 2025 by wbrum.org 10 views

Overview

The current implementation of the GeneratorTool in jOOQ allows exceptions to be thrown during code generation, but only logs them, allowing the code generator to continue. This can lead to corrupt or missing files in the output directory, making it difficult for the call site to detect the failed operation. In this article, we propose introducing a fail-fast behavior in the GeneratorTool when the Configuration.OnError value is set to FAIL.

Use Case

The current implementation of the GeneratorTool in jOOQ is designed to be robust and continue generating code even if exceptions occur during the process. However, this approach has some drawbacks. When an exception occurs, it is only logged, and the code generator continues to run. This can lead to several issues:

Corrupt or missing files: The output directory may contain corrupt or missing files, which can make it difficult to detect the failed operation.
Inspection required: The call site has to inspect the logs and/or the output directory to detect the failed operation, which can be time-consuming and error-prone.
Lack of control: The call site has no way to control the behavior of the GeneratorTool when an exception occurs, making it difficult to handle the failure.

Possible Solution

To address these issues, we propose introducing a fail-fast behavior in the GeneratorTool when the Configuration.OnError value is set to FAIL. This means that when an exception occurs during code generation, the GeneratorTool will rethrow the exception, allowing the call site to handle the failure.

Here's an example of how this can be implemented in the JavaGenerator.java class:

public class JavaGenerator {
    // ...

    public void generateDaos() {
        try {
            // Generate daos
        } catch (Exception e) {
            if (Configuration.OnError == FAIL) {
                throw e;
            } else {
                // Log the exception and continue
            }
        }
    }

    // ...
}

In this example, when an exception occurs during the generation of daos, the GeneratorTool will rethrow the exception if the Configuration.OnError value is set to FAIL. This allows the call site to handle the failure and take corrective action.

Possible Workarounds

While introducing a fail-fast behavior in the GeneratorTool is the recommended approach, there are some possible workarounds that can be used to detect failed operations:

Inspecting logs manually: The call site can inspect the logs to detect failed operations. However, this approach can be time-consuming and error-prone.
Inspecting the output directory programmatically: The call site can inspect the output directory programmatically to detect failed operations. However, this approach requires additional code and can be complex.

jOOQ Version

The proposed solution is applicable to jOOQ version 3.19.21 and later.

Database Product and Version

The proposed solution is applicable to all database products and versions.

Java Version

The proposed solution is applicable to Java version 8 and later.

JDBC / R2DBC Driver Name and Version

The proposed solution is applicable to all JDBC / R2DBC drivers.

Implementation

To implement the proposed solution, the following steps can be taken:

Update the Configuration class: Update the Configuration class to include a new value for the OnError field, which will be used to indicate whether the GeneratorTool should rethrow exceptions or log them.
Update the GeneratorTool class: Update the GeneratorTool class to rethrow exceptions when the Configuration.OnError value is set to FAIL.
Update the JavaGenerator class: Update the JavaGenerator class to use the new Configuration class and rethrow exceptions when the Configuration.OnError value is set to FAIL.

Conclusion

Q&A

Q: What is the current behavior of the GeneratorTool in jOOQ? A: The current behavior of the GeneratorTool in jOOQ is to log exceptions that occur during code generation, allowing the code generator to continue.

Q: What are the drawbacks of the current behavior? A: The current behavior has several drawbacks, including:

Corrupt or missing files: The output directory may contain corrupt or missing files, which can make it difficult to detect the failed operation.
Inspection required: The call site has to inspect the logs and/or the output directory to detect the failed operation, which can be time-consuming and error-prone.
Lack of control: The call site has no way to control the behavior of the GeneratorTool when an exception occurs, making it difficult to handle the failure.

Q: What is the proposed solution? A: The proposed solution is to introduce a fail-fast behavior in the GeneratorTool when the Configuration.OnError value is set to FAIL. This means that when an exception occurs during code generation, the GeneratorTool will rethrow the exception, allowing the call site to handle the failure.

Q: How will the fail-fast behavior be implemented? A: The fail-fast behavior will be implemented by updating the Configuration class to include a new value for the OnError field, which will be used to indicate whether the GeneratorTool should rethrow exceptions or log them. The GeneratorTool class will be updated to rethrow exceptions when the Configuration.OnError value is set to FAIL.

Q: What are the benefits of the proposed solution? A: The proposed solution has several benefits, including:

Improved control: The call site will have more control over the behavior of the GeneratorTool when an exception occurs, making it easier to handle the failure.
Reduced complexity: The proposed solution reduces the complexity of handling failed operations, making it easier to detect and handle failed operations.
Improved reliability: The proposed solution improves the reliability of the GeneratorTool by reducing the likelihood of corrupt or missing files in the output directory.

Q: What are the possible workarounds? A: There are two possible workarounds:

Inspecting logs manually: The call site can inspect the logs to detect failed operations. However, this approach can be time-consuming and error-prone.
Inspecting the output directory programmatically: The call site can inspect the output directory programmatically to detect failed operations. However, this approach requires additional code and can be complex.

Q: What is the recommended approach? A: The recommended approach is to introduce a fail-fast behavior in the GeneratorTool when the Configuration.OnError value is set to FAIL. This approach allows the call site to handle the failure and take corrective action, making it easier to detect and handle failed operations.

Q: What are the system requirements for the proposed solution? A: The proposed solution requires:

jOOQ version 3.19.21 or later: The proposed solution is applicable to jOOQ version 3.19.21 and later.
Java version 8 or later: The proposed solution is applicable to Java version 8 and later.
All database products and versions: The proposed solution is applicable to all database products and versions.
All JDBC / R2DBC drivers: The proposed solution is applicable to all JDBC / R2DBC drivers.

Q: How can the proposed solution be implemented? A: The proposed solution can be implemented by following these steps:

Update the Configuration class: Update the Configuration class to include a new value for the OnError field, which will be used to indicate whether the GeneratorTool should rethrow exceptions or log them.
Update the GeneratorTool class: Update the GeneratorTool class to rethrow exceptions when the Configuration.OnError value is set to FAIL.
Update the JavaGenerator class: Update the JavaGenerator class to use the new Configuration class and rethrow exceptions when the Configuration.OnError value is set to FAIL.