Updated on 2022-09-15 GMT+08:00

userDefined Source Table

Function

You can call APIs to obtain data from the cloud ecosystem or an open source ecosystem and use the obtained data as input of Flink jobs.

Prerequisites

The customized source class needs to inherit the RichParallelSourceFunction class and specify the data type as Row.

For example, run public class MySource extends RichParallelSourceFunction<Row>{} to declare custom class MySource. You need to implement the open, run, close, and cancel functions. Encapsulate the class into a JAR file and upload the file through the UDF JAR on the SQL editing page.

Content of the dependent pom configuration file is as follows:
<dependency>
    <groupId>org.apache.flink</groupId> 
    <artifactId>flink-streaming-java_2.11</artifactId> 
    <version>${flink.version}</version> 
    <scope>provided</scope> 
</dependency> 

<dependency> 
    <groupId>org.apache.flink</groupId> 
    <artifactId>flink-core</artifactId> 
    <version>${flink.version}</version> 
    <scope>provided</scope> 
</dependency>

Syntax

create table userDefinedSource (
  attr_name attr_type 
  (',' attr_name attr_type)* 
)
with (
  'connector.type' = 'user-defined',
  'connector.class-name' = ''
);

Parameters

Table 1 Parameter description

Parameter

Mandatory

Description

connector.type

Yes

Source type. The value can only be user-defined, indicating a custom source.

connector.class-name

Yes

Fully qualified class name of the source class

connector.class-parameter

No

Parameter of the constructor of the source class. Only one parameter of the string type is supported.

Precautions

connector.class-name must be a fully qualified class name.

Example

create table userDefinedSource (
  attr1 int,
  attr2 int
)
with (
  'connector.type' = 'user-defined',
  'connector.class-name' = 'xx.xx.MySource'
);