PDK 是其数据接口技术抽象化而来的一个开源插件开发框架，通过 Source Plugin 接口或者 Target Plugin 接口，可以快速实现新数据库作为 Tapdata 的源或目标的适配兼容，从而通过 Tapdata Cloud产品和即将开源的 Tapdata，免费获得各种异构数据源到目标数据库或平台的实时数据对接能力。

按照 PDK 连接器的开发规范进行数据源和目标端的开发，可以简化数据链路的开发流程，通过详细的开发规划和内置的 TDD 测试，可简单、快速地完成新数据源和目标端的开发工作。

支持类型包括：

接入数据库： mysql、Oracle、PostgreSQL 等

接入 SaaS 产品： Salesforce、vika 维格表、金数据表单、Zoho CRM 等

接入自定义数据源： 可对接私有协议数据源

快速开始目标数据库接入

目前，PDK 团队已将技术文档公开，大家可以前往 GitHub（https://github.com/tapdata/idaas-pdk）具体了解。

准备环境

Java 8
Maven
Git
IntelliJ IDEA

下载源码并编译

git clone https://github.com/tapdata/idaas-pdk.git

cd idaas-pdk

mvn clean install

创建目标数据库的Connector工程

例如 group 为 io.tapdata，数据库 name 为 XDB，版本 version 为 0.0.1，通过以下命令创建 Connector 工程

目标数据库无需建表时

./bin/tap template --type target --group io.tapdata --name XDB --version 0.0.1 --output ./connectors

用 ItelliJ IDEA 打开 idaas-pdk，在 idaas-pdk/connectors 下就能看见 xdb-connector 工程。

在 spec.json 里填写 configOptions

configOptions 集成到 Tapdata 站点之后，配置给用户在使用该Connector的时候的输入项，例如数据库的连接地址，用户名，密码等等



   ...

   "configOptions":

      "connection":

         "type":"object",

         "properties":

            "host":

               "type": "string",

               "title": "Host",

               "x-decorator": "FormItem",

               "x-component": "Input"

            , 

            "port":

               "type": "number",

               "title": "Port",

               "x-decorator": "FormItem",

               "x-component": "Input"

编写接入目标数据库的代码

@TapConnectorClass("spec.json")

public class XDBConnector extends ConnectorBase implements TapConnector 

 @Override

    public void discoverSchema(TapConnectionContext connectionContext, Consumer<List<TapTable>> consumer) 

        //TODO Load tables from database, connection information in connectionContext#getConnectionConfig

        //Sample code shows how to define tables.

        consumer.accept(list(

                //Define first table

                table("empty-table1"),

                //Define second table

                table("empty-table2"))

        ));

    


 @Override

    public void connectionTest(TapConnectionContext connectionContext, Consumer<TestItem> consumer) 

        //Assume below tests are successfully, below tests are recommended, but not required.

        //Connection test

        //TODO execute connection test here

        consumer.accept(testItem(TestItem.ITEM_CONNECTION, TestItem.RESULT_SUCCESSFULLY));

        //Login test

        //TODO execute login test here

        consumer.accept(testItem(TestItem.ITEM_LOGIN, TestItem.RESULT_SUCCESSFULLY));

        //Read test

        //TODO execute read test by checking role permission

        consumer.accept(testItem(TestItem.ITEM_READ, TestItem.RESULT_SUCCESSFULLY));

        //Write test

        //TODO execute write test by checking role permission

        consumer.accept(testItem(TestItem.ITEM_WRITE, TestItem.RESULT_SUCCESSFULLY));

    


 private void writeRecord(TapConnectorContext connectorContext, List<TapRecordEvent> tapRecordEvents, Consumer<WriteListResult<TapRecordEvent>> writeListResultConsumer) 

        //TODO write records into database

        //Below is sample code to print received events which suppose to write to database.

        AtomicLong inserted = new AtomicLong(0); //insert count

        AtomicLong updated = new AtomicLong(0); //update count

        AtomicLong deleted = new AtomicLong(0); //delete count

        for(TapRecordEvent recordEvent : tapRecordEvents) 

            if(recordEvent instanceof TapInsertRecordEvent) 

                //TODO insert record

                inserted.incrementAndGet();

             else if(recordEvent instanceof TapUpdateRecordEvent) 

                //TODO update record

                updated.incrementAndGet();

             else if(recordEvent instanceof TapDeleteRecordEvent) 

                //TODO delete record

                deleted.incrementAndGet();

            

        

        //Need to tell incremental engine the write result

        writeListResultConsumer.accept(writeListResult()

                .insertedCount(inserted.get())

                .modifiedCount(updated.get())

                .removedCount(deleted.get()));

    

 private void queryByFilter(TapConnectorContext connectorContext, List<TapFilter> filters, Consumer<List<FilterResult>> listConsumer)

        //Filter is exactly match.

        //If query by the filter, no value is in database, please still create a FitlerResult with null value in it. So that flow engine can understand the filter has no value.

目标数据库须建表时

./bin/tap template --type targetNeedTable --group io.tapdata --name XDB --version 0.0.1 --output ./connectors

用 ItelliJ IDEA 打开 idaas-pdk，在 idaas-pdk/connectors 下就能看见 xdb-connector 工程。

在 spec.json 里填写 configOptions

configOptions 集成到 Tapdata 站点之后，配置给用户在使用该 Connector 的时候的输入项，例如数据库的连接地址、用户名、密码等


   ...

   "configOptions":

      "connection":

         "type":"object",

         "properties":

            "host":

               "type": "string",

               "title": "Host",

               "x-decorator": "FormItem",

               "x-component": "Input"

            , 

            "port":

               "type": "number",

               "title": "Port",

               "x-decorator": "FormItem",

               "x-component": "Input"

在 spec.json 里填写 dataTypes（类型表达式）

dataTypes 用于描述该 Connector 接入数据库的所有字段的范围，以及转换到对应的 TapType。源端数据库也会提供相同的 dataTypes 描述，这样当源端数据流入到 Tapdata 里时，会结合源端 dataTypes 的字段描述信息结合源端库表的字段信息，通过 Tapdata 的中立数据结构进入到 Tapdata 的数据流中，当数据要流入到目标数据库之前，Tapdata 会根据这些信息，在目标库的 dataTypes 中找到最佳的存储字段，通过 TapField 的 originType 告知给 PDK 开发者，用以建表。



   ...

   "dataTypes":

      "boolean":"bit":8, "unsigned":"", "to":"TapNumber",

      "tinyint":"bit":8, "to":"TapNumber",

      "smallint":"bit":16, "to":"TapNumber",

      "int":"bit":32, "to":"TapNumber",

      "bigint":"bit":64, "to":"TapNumber",

      "largeint":"bit":128, "to":"TapNumber",

      "float":"bit":32, "to":"TapNumber",

      "double":"bit":64, "to":"TapNumber",

      "decimal[($precision,$scale)]":"bit": 128, "precision": [1, 27], "defaultPrecision": 10, "scale": [0, 9], "defaultScale": 0, "to": "TapNumber",

      "date":"byte":3, "range":["0000-01-01", "9999-12-31"], "to":"TapDate",

      "datetime":"byte":8, "range":["0000-01-01 00:00:00","9999-12-31 23:59:59"],"to":"TapDateTime",

      "char[($byte)]":"byte":255, "to": "TapString", "defaultByte": 1,

      "varchar[($byte)]":"byte":"65535", "to":"TapString",

      "string":"byte":"2147483643", "to":"TapString",

      "HLL":"byte":"16385", "to":"TapNumber", "queryOnly":true

编写接入目标数据库的代码

 @TapConnectorClass("spec.json")

public class XDBConnector extends ConnectorBase implements TapConnector 
 @Override

 public void discoverSchema(TapConnectionContext connectionContext, Consumer<List<TapTable>> consumer) 
 //TODO Load schema from database, connection information in connectionContext#getConnectionConfig
 //Sample code shows how to define tables with specified fields
 consumer.accept(list(
 //Define first table
 table("empty-table1")
 //Define a field named "id", origin field type, whether is primary key and primary key position

 .add(field("id", "varchar").isPrimaryKey(true).partitionKeyPos(1))

 .add(field("description", "string"))

 .add(field("name", "varchar"))

 .add(field("age", "int")))

 ));

 

 @Override

 public void connectionTest(TapConnectionContext connectionContext, Consumer<TestItem> consumer) 

 //Assume below tests are successfully, below tests are recommended, but not required.
 //Connection test
 //TODO execute connection test here
 consumer.accept(testItem(TestItem.ITEM_CONNECTION, TestItem.RESULT_SUCCESSFULLY));
 //Login test

 //TODO execute login test here

 consumer.accept(testItem(TestItem.ITEM_LOGIN, TestItem.RESULT_SUCCESSFULLY));

 //Read test

 //TODO execute read test by checking role permission
 consumer.accept(testItem(TestItem.ITEM_READ, TestItem.RESULT_SUCCESSFULLY));

 //Write test
 //TODO execute write test by checking role permission
 consumer.accept(testItem(TestItem.ITEM_WRITE, TestItem.RESULT_SUCCESSFULLY));

 

 @Override

 public void registerCapabilities(ConnectorFunctions connectorFunctions, TapCodecRegistry codecRegistry) 

 connectorFunctions.supportWriteRecord(this::writeRecord);
 connectorFunctions.supportQueryByFilter(this::queryByFilter);

 //If database need insert record before table created, then please implement the below two methods.
 connectorFunctions.supportCreateTable(this::createTable);
 connectorFunctions.supportDropTable(this::dropTable);

 //If database need insert record before table created, please implement the custom codec for the TapValue that data types in spec.json didn't cover.

 //TapTimeValue, TapMapValue, TapDateValue, TapArrayValue, TapYearValue, TapNumberValue, TapBooleanValue, TapDateTimeValue, TapBinaryValue, TapRawValue, TapStringValue

 codecRegistry.registerFromTapValue(TapRawValue.class, "text", tapRawValue -> 

 if (tapRawValue != null && tapRawValue.getValue() != null)

 return toJson(tapRawValue.getValue());

 return "null";

 );

 


 private void writeRecord(TapConnectorContext connectorContext, List<TapRecordEvent> tapRecordEvents, Consumer<WriteListResult<TapRecordEvent>> writeListResultConsumer) 

 //TODO write records into database

 //Below is sample code to print received events which suppose to write to database.

 AtomicLong inserted = new AtomicLong(0); //insert count

 AtomicLong updated = new AtomicLong(0); //update count

 AtomicLong deleted = new AtomicLong(0); //delete count

 for(TapRecordEvent recordEvent : tapRecordEvents) 

 if(recordEvent instanceof TapInsertRecordEvent) 

 //TODO insert record

 inserted.incrementAndGet();

 PDKLogger.info(TAG, "Record Write TapInsertRecordEvent ", toJson(recordEvent));

  else if(recordEvent instanceof TapUpdateRecordEvent) 

 //TODO update record

 updated.incrementAndGet();

 PDKLogger.info(TAG, "Record Write TapUpdateRecordEvent ", toJson(recordEvent));

  else if(recordEvent instanceof TapDeleteRecordEvent) 

 //TODO delete record

 deleted.incrementAndGet();

 PDKLogger.info(TAG, "Record Write TapDeleteRecordEvent ", toJson(recordEvent));

 

 

 //Need to tell incremental engine the write result

 writeListResultConsumer.accept(writeListResult()

 .insertedCount(inserted.get())

 .modifiedCount(updated.get())

 .removedCount(deleted.get()));

 

 private void queryByFilter(TapConnectorContext connectorContext, List<TapFilter> filters, Consumer<List<FilterResult>> listConsumer)

 //Filter is exactly match.

 //If query by the filter, no value is in database, please still create a FitlerResult with null value in it. So that flow engine can understand the filter has no value.

 

 private void dropTable(TapConnectorContext connectorContext, TapDropTableEvent dropTableEvent) 

 TapTable table = connectorContext.getTable();

 //TODO implement drop table

 

 private void createTable(TapConnectorContext connectorContext, TapCreateTableEvent createTableEvent) 

 //TODO implement create table.

 TapTable table = connectorContext.getTable();

 LinkedHashMap<String, TapField> nameFieldMap = table.getNameFieldMap();

 for(Map.Entry<String, TapField> entry : nameFieldMap.entrySet()) 

 TapField field = entry.getValue();

 String originType = field.getOriginType();

 //originType is the data types defined in spec.json

 //TODO use the generated originType to create table.

开发完成之后通过 TDD 进行测试验证

提供 configOptions 里需要用户填写的内容的 json 文件，例如上述 configOptions 里要求用户填写的是数据库的 Host 和 Port，那么 tdd 的 xdb_tdd.json 文件内容如下：


    "connection": 

      "host": "192.168.153.132",

      "port": 9030,

执行 TDD 测试命令：

./bin/tap tdd --testConfig xdb_tdd.json ./connectors/xdb-connector

当 TDD 测试没有通过，请根据错误提示修改对应错误，直至通过 TDD测试；

当 TDD 测试通过后， PDK Connector 就处于可以提交 Pull Request 的状态。

如何提交到 PDK 开源项目

① fork idaas-pdk，基于远程的 main 分支建立本地分支

② 根据要接入数据库名称，在 idaas-pdk/connectors 目录下新建模块，命名规范为数据库小写名称-connector，例如接入数据库的名称为 XDB，模块名称为 xdb-connector

③ 开发者根据官方 API 文档完成接入数据库的开发实现

④ 通过 TDD 测试后，提交 PR 到 idaas-pdk

⑤ 官方团队 Review 提交的 PR 之后合并代码

彩蛋

感兴趣的同学先别急着开发，据了解，官方推出的免费版本，已陆续实现30个常见数据源/目标间的实时数据对接，如果其中已经包含了你想要接入的数据库，完全可以直接使用 Tapdata Cloud（Tapdata Cloud | 免费的异构数据库实时同步云平台 - Tapdata）进行免费数据实时同步。当然，如果你的需求现阶段还不被支持，就可以通过Tapdata PDK 自助开发，快速接入。

Tapdata Cloud 现阶段支持的数据连接类型

目前，Tapdata 开放了面向开发者的插件生态共建群，开发过程中可以提供技术交流和支持，感兴趣的同学可以扫码关注，拉你入群：

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