Custom SerDes in Kafka - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to implement the serialize method in a custom Kafka Serializer.

Kafka

public byte[] serialize(String topic, [1] data) {
    if (data == null) {
        return null;
    }
    return data.getBytes(StandardCharsets.UTF_8);
}

Drag options to blanks, or click blank then click option'

Aint

BString

Cbyte[]

DObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using int or Object as the data type causes compile errors.

Using byte[] as input is incorrect because serialize expects the original data type.

The serialize method takes the data to serialize, which is a String in this example, so the parameter type should be String.

2fill in blank

medium

Complete the code to implement the deserialize method in a custom Kafka Deserializer.

Kafka

public String deserialize(String topic, [1] data) {
    if (data == null) {
        return null;
    }
    return new String(data, StandardCharsets.UTF_8);
}

Drag options to blanks, or click blank then click option'

AObject

BString

Cint

Dbyte[]

Attempts:

3 left

💡 Hint

Common Mistakes

Using String as input causes errors because data is raw bytes.

Using int or Object as input is incorrect.

The deserialize method receives the data as a byte array, so the parameter type must be byte[].

3fill in blank

hard

Fix the error in the custom Serializer class declaration.

Kafka

public class CustomSerializer implements Serializer<[1]> {
    // implementation
}

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AString

BInteger

Cbyte[]

DObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using byte[] or Object as generic type causes mismatch errors.

Using Integer when data is String causes type errors.

The Serializer interface should be parameterized with the data type you want to serialize, here String.

4fill in blank

hard

Fill both blanks to complete the custom Deserializer class declaration and method signature.

Kafka

public class CustomDeserializer implements Deserializer<[1]> {
    @Override
    public [2] deserialize(String topic, byte[] data) {
        if (data == null) return null;
        return new String(data, StandardCharsets.UTF_8);
    }
}

Drag options to blanks, or click blank then click option'

AString

Bbyte[]

DObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using byte[] as generic type or return type causes errors.

Mixing Object and String types causes type mismatch.

The Deserializer generic type and the deserialize method return type must both be String to match the data type.

5fill in blank

hard

Fill all three blanks to complete the custom SerDes class with serializer, deserializer, and configure method.

Kafka

public class CustomSerDes implements Serializer<[1]>, Deserializer<[2]> {

    @Override
    public byte[] serialize(String topic, [3] data) {
        if (data == null) return null;
        return data.getBytes(StandardCharsets.UTF_8);
    }

    @Override
    public [2] deserialize(String topic, byte[] data) {
        if (data == null) return null;
        return new String(data, StandardCharsets.UTF_8);
    }

    @Override
    public void configure(Map<String, ?> configs, boolean isKey) {
        // configuration code if needed
    }

    @Override
    public void close() {
        // cleanup code if needed
    }
}

Drag options to blanks, or click blank then click option'

AString

Bbyte[]

DObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using byte[] or Object as generic or parameter types causes type errors.

Mismatch between generic types and method parameter/return types.

The SerDes class handles String data type for both serializer and deserializer, so all generic and parameter types are String.