I have created a simple GraphQL endpoint using Spring Boot and I am using DefaultGraphQLErrorHandler() to handle GraphQL errors.

However, when I throw a custom Exception from my application, the error response which GraphQL produces contains Exception stack trace which is giving away too much information. I want to prevent this.

{
"data": {
    "CommercialAsset": null
},
"errors": [
    {
        "message": "Exception while fetching data (/CommercialAsset) : Asset not fround in Data source",
        "path": [
            "CommercialAsset"
        ],
        "exception": {
            "cause": null,
            "stackTrace": [
                {
                    "classLoaderName": null,
                    "moduleName": null,
                    "moduleVersion": null,
                    "methodName": "getAssetById",
                    "fileName": "CommercialAssetDremioRepositoryImpl.java",
                    "lineNumber": 49,
                    "className": "com.dell.dremioclient.repository.impl.CommercialAssetDremioRepositoryImpl",
                    "nativeMethod": false
                },
                ...
                {
                    "classLoaderName": null,
                    "moduleName": "java.base",
                    "moduleVersion": "11.0.14",
                    "methodName": "run",
                    "fileName": "Thread.java",
                    "lineNumber": 834,
                    "className": "java.lang.Thread",
                    "nativeMethod": false
                }
            ],
            "message": "Asset not fround in Data source",
            "locations": null,
            "errorType": null,
            "path": null,
            "extensions": null,
            "suppressed": [],
            "localizedMessage": "Asset not fround in Data source"
        },
        "locations": [
            {
                "line": 2,
                "column": 5,
                "sourceName": null
            }
        ],
        "extensions": null,
        "errorType": "DataFetchingException"
    }
]

}

GraphQL dependency versions that I am using :

    <dependency>
       <groupId>com.graphql-java</groupId>
        <artifactId>graphql-spring-boot-starter</artifactId>
        <version>5.0.2</version>
    </dependency>
    <dependency>
        <groupId>com.graphql-java</groupId>
        <artifactId>graphql-java-tools</artifactId>
        <version>5.2.4</version>
    </dependency>
    <dependency>
        <groupId>com.graphql-java</groupId>
        <artifactId>graphiql-spring-boot-starter</artifactId>
        <version>5.0.2</version>
    </dependency>

Is there any way I can do it using Custom error handler? Something like this -

public class CustomGraphqlErrorHandler implements GraphQLErrorHandler {

@Override
public List<GraphQLError> processErrors(List<GraphQLError> errors) {
    
    List<GraphQLError> errorList = new ArrayList<>();
    
    errors.stream()
            .forEach( e -> {
                if(this.isServerError(e)) {
                    GraphqlDremioClientException gexp = new GraphqlDremioClientException(e.getMessage());
                    gexp.setStackTrace(null); /* This causes failure Bad POST request: parsing failed
                                                 java.lang.NullPointerException: null
                                                 at java.base/java.lang.Throwable.setStackTrace(Throwable.java:865) */
                    errorList.add(gexp);
                } else {
                    errorList.add(e);
                }
            });
    
    return errorList;
}

private boolean isServerError(GraphQLError error) {
    return (error instanceof ExceptionWhileDataFetching || error instanceof Throwable);
}

@Override
public boolean errorsPresent(List<GraphQLError> errors) {
    return !CollectionUtils.isEmpty(errors);
}

}

CodePudding user response：

I wanted to prevent GraphQL to show stack trace in the error response. One simple solution to it was to add a custom GraphQL error handler to handle the exceptions thrown from my services. I then, created a custom Exception class which could enable or disable stack trace during construction.

Custom Exception class:

public class GraphqlDremioClientException extends RuntimeException implements GraphQLError {

    private static final long serialVersionUID = 1L;
    
    private final String message;
    
    private boolean noStacktrace = false;

    @Override
    public String getMessage() {
        return message;
    }
    /* other constructors */
        
    public GraphqlDremioClientException(String message, boolean noStacktrace) {
        super(message, null, false, noStacktrace);
        this.noStacktrace = noStacktrace;
        this.message = message;
    }
    
    public GraphqlDremioClientException(String message, Exception ex) {
        super();
        this.message = message;
    }

    @Override
    public List<SourceLocation> getLocations() {
        return null;
    }

    @Override
    public ErrorType getErrorType() {
        return null;
    }       
}

Custome GraphQL error handler:

@Slf4j
@Component
public class CustomGraphqlErrorHandler implements GraphQLErrorHandler {

    @Override
    public List<GraphQLError> processErrors(List<GraphQLError> list) {
        return list.stream().map(this::getNested).collect(Collectors.toList());
    }
    
    private GraphQLError getNested(GraphQLError error) {
        log.error(error.getMessage(), error);
        
        if (error instanceof ExceptionWhileDataFetching) {
            ExceptionWhileDataFetching exceptionError = (ExceptionWhileDataFetching) error;
            if (exceptionError.getException() instanceof GraphQLError) {
                return new GraphqlDremioClientException(exceptionError.getMessage(), false);
            }
        }
        return error;
    }
}

The error response now:

{
    "data": {
        "CommercialAsset": null
    },
    "errors": [
        {
            "cause": null,
            "stackTrace": [],
            "message": "Exception while fetching data (/CommercialAsset) : Asset not fround in Data source",
            "noStacktrace": false,
            "locations": null,
            "errorType": null,
            "path": null,
            "extensions": null,
            "suppressed": [],
            "localizedMessage": "Exception while fetching data (/CommercialAsset) : Asset not fround in Data source"
        }
    ]
}