Java中处理抽象类字段的多态性JSON反序列化策略

import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import jakarta.persistence.Entity; // 假设使用JPA，但此处主要针对Jackson
import jakarta.persistence.Id;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;

// 抽象基类 SourceConfig
@JsonTypeInfo(
    use = JsonTypeInfo.Id.NAME, // 使用名称作为类型标识
    include = JsonTypeInfo.As.PROPERTY, // 类型标识作为JSON的一个属性
    property = "type" // 类型标识属性的名称
)
@JsonSubTypes({
    @JsonSubTypes.Type(value = KafkaSourceConfig.class, name = "KAFKA"),
    @JsonSubTypes.Type(value = MysqlSourceConfig.class, name = "MYSQL")
})
public abstract class SourceConfig {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
    private String name;

    // Getters and Setters
    public long getId() { return id; }
    public void setId(long id) { this.id = id; }
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
}

// KafkaSourceConfig 子类
public class KafkaSourceConfig extends SourceConfig {
    private String topic;
    private String messageSchema;

    // Getters and Setters
    public String getTopic() { return topic; }
    public void setTopic(String topic) { this.topic = topic; }
    public String getMessageSchema() { return messageSchema; }
    public void setMessageSchema(String messageSchema) { this.messageSchema = messageSchema; }
}

// MysqlSourceConfig 子类
public class MysqlSourceConfig extends SourceConfig {
    private String databaseName;
    private String tableName;

    // Getters and Setters
    public String getDatabaseName() { return databaseName; }
    public void setDatabaseName(String databaseName) { this.databaseName = databaseName; }
    public String getTableName() { return tableName; }
    public void setTableName(String tableName) { this.tableName = tableName; }
}

// Pipeline 类
public class Pipeline {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
    private String name;
    private SourceConfig sourceConfig; // 保持抽象类型字段
    // private SinkConfig sinkConfig; // 类似处理，此处省略

    // Getters and Setters
    public long getId() { return id; }
    public void setId(long id) { this.id = id; }
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    public SourceConfig getSourceConfig() { return sourceConfig; }
    public void setSourceConfig(SourceConfig sourceConfig) { this.sourceConfig = sourceConfig; }
}

{
    "name": "mysql_to_bq_1",
    "sourceConfig": {
        "type": "MYSQL",  // 关键的类型标识符
        "databaseName": "my_db",
        "tableName": "my_table",
        "name": "MySQL Source Config" // SourceConfig 的字段
    },
    "sinkConfig": {
        // ... sink config details
    },
    "createdBy": "paul"
}

// 假设你已经通过Spring MVC或其他方式接收并反序列化了Pipeline对象
// ObjectMapper objectMapper = new ObjectMapper();
// Pipeline pipeline = objectMapper.readValue(jsonString, Pipeline.class);
Pipeline pipeline = ...; // 获取已反序列化的Pipeline实例

SourceConfig config = pipeline.getSourceConfig();

if (config instanceof KafkaSourceConfig) {
    KafkaSourceConfig kafkaConfig = (KafkaSourceConfig) config;
    System.out.println("Kafka Topic: " + kafkaConfig.getTopic());
    // 执行KafkaSourceConfig特有的操作
} else if (config instanceof MysqlSourceConfig) {
    MysqlSourceConfig mysqlConfig = (MysqlSourceConfig) config;
    System.out.println("MySQL Database: " + mysqlConfig.getDatabaseName());
    // 执行MysqlSourceConfig特有的操作
} else {
    System.out.println("Unknown SourceConfig type.");
}