Spring XD jdbc（源）-> jdbc（接收器）

Question

I'm trying to configure streams like below (directly pipe from jdbc source to jdbc sink)

xd> stream create test2 --definition "output:jdbc --split=true --username=test --password=test --driverClassName=com.mysql.jdbc.Driver --url=jdbc:mysql://dbhost:3306/test --query='select id,name from test' | input:jdbc --username=test --password=test --driverClassName=com.mysql.jdbc.Driver --tableName=test2 --columns=id,name --url=jdbc:mysql://dbhost:3306/test" --deploy

but occurs ClassCastException.

Caused by: java.lang.ClassCastException: org.springframework.util.LinkedCaseInsensitiveMap cannot be cast to java.lang.String at org.springframework.xd.jdbc.JdbcMessagePayloadTransformer.transformPayload(JdbcMessagePayloadTransformer.java:39) at org.springframework.integration.transformer.AbstractPayloadTransformer.doTransform(AbstractPayloadTransformer.java:33) at org.springframework.integration.transformer.AbstractTransformer.transform(AbstractTransformer.java:33) ... 147 more

MySQL connection and table schema seems properly configured. connectivity already confirmed.

CREATE TABLE test (id int, name varchar(20)); CREATE TABLE test2 (id int, name varchar(20))

Spring XD version is 1.1.0.BUILD-20141103.163150-1-dist from zip below.

http://repo.spring.io/libs-snapshot/org/springframework/xd/spring-xd/1.1.0.BUILD-SNAPSHOT/spring-xd-1.1.0.BUILD-20141103.163150-1-dist.zip

I want to store the payload data to target sink table, but is the functionality still experimental?
or, Is it the stream problem, for example just racks some kind of conversion?

Answer 1

Like Gary said, the sink expects a JSON document (there is an outstanding JIRA ticket to improve the sink to also accept a Map). For now you can have the source produce a JSON document instead of a Map using --outputType=application/json. Here is an example I just tried:

stream create jdbcCp --definition "source:jdbc --query='select id,name,year from myfiles where status = 0' --maxRowsPerPoll=10 --update='update myfiles set status = 1 where id in (:id)' --outputType=application/json | sink:jdbc --tableName=newfiles --columns=id,name,year"  --deploy

The JIRA issue is https://jira.spring.io/browse/XD-2250

Answer 2

See the documentation - the sink expects a simple String payload or a JSON String that will be converted to a Map . The source produces a List of Map s (or individual Map s when split is true).

Currently there is no option for the sink to handle a Map directly; you could add a transform module to convert the Map to JSON or create a custom sink.

We should probably change the sink to accept a Map .