How can i handle CAMEL jdbc connection exception? - mysql

Question

<from uri="sql:select * from params?dataSource=moodleDB"/>
exception:
org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:
** BEGIN NESTED EXCEPTION **
java.net.ConnectException
MESSAGE: Connection refused: connect
STACKTRACE:
java.net.ConnectException: Connection refused: connect
How can i catch this exception ?

Answer 1

Usually from endpoints don't tend to throw exceptions, I would try to work around having something else that starts your program and then I would follow up with an exception handler. The error handler will retry from whatever step failed if you want retries and you can set different behaviors for different exception types. This error handler would be used for your whole context, but you can also set them up at route level. More information can be found here: http://camel.apache.org/error-handling-in-camel.html
onException(Exception.class)
.handled(true)
.log(LoggingLevel.ERROR, "${exception.stackTrace}")
.stop();
from("timer://RunOnStartupOnceTimer?repeatCount=1")
.to("sql:select * from params?dataSource=moodleDB")
.to("moreProcessing");

Answer 2

Also you can use one of error handlers.
More information can be found here: http://camel.apache.org/error-handler.html
#Override
public void configure() throws Exception {
errorHandler(deadLetterChannel("direct:sqlErrorHandler"));
from("sql:select * from params?dataSource=moodleD")......
from("direct:sqlErrorHandler")
.log(LoggingLevel.ERROR, "The exception occurred: ${exception.message}").
.log(LoggingLevel.ERROR, "Exception stacktrace : ${exception.stacktrace}").
.log(LoggingLevel.INFO, "SQL operation error!");
}