在Spring Cassandra中将Map转换为Set

@Table("users")
public class User {
    @PrimaryKey
    private UUID id;
    
    private Map<String, String> properties;
    
    // getters and setters
}

public class CustomCassandraConverter implements CassandraConverter {
    // 实现接口中的方法，包括将Map转换为Set的逻辑
}

public class CustomCassandraConverter implements CassandraConverter {
    // ...

    @Override
    public <T> T read(Class<T> type, Row row) {
        // ...
    }

    @Override
    public void write(Object source, Set<ColumnValue> columns) {
        if (source instanceof User) {
            User user = (User) source;
            Map<String, String> properties = user.getProperties();
            Set<ColumnValue> propertyColumns = properties.entrySet().stream()
                    .map(entry -> ColumnValue.of(entry.getKey(), entry.getValue()))
                    .collect(Collectors.toSet());
            columns.addAll(propertyColumns);
        }
    }

    // ...
}

@Configuration
@EnableCassandraRepositories(basePackages = "com.example.repository", cassandraConverterRef = "customCassandraConverter")
public class CassandraConfig extends AbstractCassandraConfiguration {
    // ...

    @Bean
    public CassandraConverter customCassandraConverter() {
        return new CustomCassandraConverter();
    }

    // ...
}