Java中处理抽象类字段的多态性及其在数据序列化中的应用

// Pipeline类，包含抽象配置字段
public class Pipeline {
    private long id;
    private String name;
    private SourceConfig sourceConfig; // 抽象类型字段
    private SinkConfig sinkConfig;     // 抽象类型字段
    // ... 其他字段和方法
}

// 抽象的源配置基类
public abstract class SourceConfig {
    private long id;
    private String name;
    // ... getters/setters
}

// Kafka源配置
public class KafkaSourceConfig extends SourceConfig {
    private String topic;
    private String messageSchema;
    // ... getters/setters
}

// MySQL源配置
public class MysqlSourceConfig extends SourceConfig {
    private String databaseName;
    private String tableName;
    // ... getters/setters
}

// 抽象的汇配置基类 (类似SourceConfig)
public abstract class SinkConfig {
    private long id;
    private String name;
    // ... getters/setters
}

// ... 可能还有具体的SinkConfig子类

public class Pipeline {
    private long id;
    private String name;
    private KafkaSourceConfig kafkaSourceConfig; // 具体子类字段
    private MysqlSourceConfig mysqlSourceConfig; // 具体子类字段
    // ...
}

public class Pipeline {
    // ...
    private SourceConfig sourceConfig; // 声明为抽象父类类型
    // ...
}

public void processPipeline(Pipeline pipeline) {
    SourceConfig config = pipeline.getSourceConfig();
    if (config instanceof KafkaSourceConfig) {
        KafkaSourceConfig kafkaConfig = (KafkaSourceConfig) config;
        System.out.println("Kafka Topic: " + kafkaConfig.getTopic());
    } else if (config instanceof MysqlSourceConfig) {
        MysqlSourceConfig mysqlConfig = (MysqlSourceConfig) config;
        System.out.println("MySQL Database: " + mysqlConfig.getDatabaseName());
    } else {
        System.out.println("Unknown SourceConfig type.");
    }
}

{
    "name": "mysql_to_bq_1",
    "sourceConfig": {
        "source": "MYSQL", // 或其他类型标识
        "databaseName": "mydb",
        "tableName": "mytable"
    },
    "sinkConfig": {
        // ...
    },
    "createdBy": "paul"
}

import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.JsonTypeName; // 用于指定子类的名称

// Pipeline类保持不变，字段类型为抽象类
public class Pipeline {
    // @Id, @GeneratedValue等JPA注解省略，此处关注JSON序列化/反序列化
    private long id;
    private String name;
    private SourceConfig sourceConfig;
    private SinkConfig sinkConfig;
    private String createdBy;

    // 构造函数、getter/setter省略
}

// 抽象的源配置基类
@JsonTypeInfo(
    use = JsonTypeInfo.Id.NAME, // 使用一个名称作为类型标识
    include = JsonTypeInfo.As.PROPERTY, // 类型标识作为独立的JSON属性
    property = "type" // 类型标识属性的名称为"type"
)
@JsonSubTypes({
    @JsonSubTypes.Type(value = KafkaSourceConfig.class, name = "KAFKA"), // KAFKA对应KafkaSourceConfig
    @JsonSubTypes.Type(value = MysqlSourceConfig.class, name = "MYSQL")  // MYSQL对应MysqlSourceConfig
})
public abstract class SourceConfig {
    private long id;
    private String name;
    // ... getters/setters
}

// Kafka源配置
@JsonTypeName("KAFKA") // 指定该子类对应的类型名称
public class KafkaSourceConfig extends SourceConfig {
    private String topic;
    private String messageSchema;
    // ... getters/setters
}

// MySQL源配置
@JsonTypeName("MYSQL") // 指定该子类对应的类型名称
public class MysqlSourceConfig extends SourceConfig {
    private String databaseName;
    private String tableName;
    // ... getters/setters
}

// 抽象的汇配置基类 (类似SourceConfig，也需要Jackson注解)
@JsonTypeInfo(
    use = JsonTypeInfo.Id.NAME,
    include = JsonTypeInfo.As.PROPERTY,
    property = "type"
)
@JsonSubTypes({
    // ... 添加具体的SinkConfig子类
})
public abstract class SinkConfig {
    private long id;
    private String name;
    // ... getters/setters
}

{
    "name": "mysql_to_bq_1",
    "sourceConfig": {
        "type": "MYSQL", // 这个"type"属性是关键！
        "name": "my_mysql_source",
        "databaseName": "mydb",
        "tableName": "mytable"
    },
    "sinkConfig": {
        "type": "BQ", // 假设有BigQuerySinkConfig
        "name": "my_bq_sink",
        "datasetId": "my_dataset"
    },
    "createdBy": "paul"
}