org.apache.kafka.common.errors.SerializationException: Error deserializing... Caused by: org.apache.kafka.common.errors.SerializationException: Size of data received by IntegerDeserializer is not 4

原因，最近開發的kafka消息接收，突然報如下錯：

org.apache.kafka.common.errors.SerializationException: Error deserializing... Caused by: org.apache.kafka.common.errors.SerializationException: Size of data received by IntegerDeserializer is not 4

原因如下，我的kafka序列化配置中配置的序列化類如下：

key.deserializer=org.apache.kafka.common.serialization.IntegerDeserializer
value.deserializer=org.apache.kafka.common.serialization.StringDeserializer

IntegerDeserializer源碼如下：

public Integer deserialize(String topic, byte[] data) {
        if (data == null) {
            return null;
        } else if (data.length != 4) {
            throw new SerializationException("Size of data received by IntegerDeserializer is not 4");
        } else {
            int value = 0;
            byte[] arr$ = data;
            int len$ = data.length;

            for(int i$ = 0; i$ < len$; ++i$) {
                byte b = arr$[i$];
                value <<= 8;
                value |= b & 255;
            }

            return value;
        }
    }

解決方法，將配置做如下修改：

key.deserializer=org.apache.kafka.common.serialization.StringDeserializer
value.deserializer=org.apache.kafka.common.serialization.StringDeserializer

問題解決。