Troubleshooting IllegalAccessError in Plaid Integration

When integrating Plaid with Retrofit and Gson, you may encounter an IllegalAccessError. This typically arises due to version conflicts between the Gson library used by Retrofit and the one specified in your project. Below are steps to resolve this issue.

Maven Configuration

Ensure your Maven pom.xml includes the correct dependencies and exclusions to avoid conflicts. Here’s a sample configuration:

<dependencies>
    <dependency>
        <groupId>com.squareup.retrofit2</groupId>
        <artifactId>converter-gson</artifactId>
        <version>2.2.0</version>
        <exclusions>
            <exclusion>
                <groupId>com.google.code.gson</groupId>
                <artifactId>gson</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.8.0</version>
    </dependency>
</dependencies>

Explanation of Configuration

• The converter-gson dependency is included with a specific version (2.2.0) and excludes the default Gson library that it might bring in.
• The explicit inclusion of Gson version 2.8.0 ensures that your project uses the correct version, which is compatible with Retrofit.

Understanding the Error

The error message you might see is similar to:

java.lang.IllegalAccessError: tried to access method com.google.gson.Gson.newJsonWriter(Ljava/io/Writer;)Lcom/google/gson/stream/JsonWriter; from class retrofit2.converter.gson.GsonRequestBodyConverter

This indicates that the Gson version being used does not match what Retrofit expects, leading to access issues.

Conclusion

By ensuring that your Maven configuration specifies compatible versions of Gson and Retrofit, you can resolve the IllegalAccessError and successfully integrate Plaid into your application. If issues persist, consider checking for other dependencies that might also include Gson and ensure they are excluded or updated accordingly.