Autowired annotation is ignored in camel process statement - apache-camel

Question

I need to implement db connection and query in process step.
So, I defined datasource in bean property.
And I tried to use jdbctemplate.
But result is returned with java.lang.NullPointException.
Do camel ignore autowired annotation in process statement?
If there is another solution, let me know it please.
Thank you.
CamelContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:camel="http://camel.apache.org/schema/spring"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
...
http://camel.apache.org/schema/spring/camel-spring.xsd">
<bean class="com.ktds.openmzn.common.bean.ProcFormat" id="procFormat"/>
<bean class="com.ktds.openmzn.common.bean.ProcessDistributor" id="splitChannel"/>
<bean class="org.springframework.jdbc.datasource.DriverManagerDataSource" id="dataSource">
<property name="driverClassName" value="${spring.datasource.driver-class-name}"/>
<property name="url" value="${spring.datasource.url}"/>
<property name="username" value="${spring.datasource.username}"/>
<property name="password" value="${spring.datasource.password}"/>
</bean>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource" />
</bean>
<bean class="com.ktds.openmzn.common.bean.FilePathProcessor" id="filePathProcessor"/>
...
<camelContext id="camelContext-f611cb6c-d516-4346-9adc-5512d327a88d"
trace="true" xmlns="http://camel.apache.org/schema/spring">
<camel:route id="fixed_processor">
<camel:from id="_from1" uri="timer:fromPollTimer?period=20000"/>
<camel:process id="_sourceDirectory" ref="filePathProcessor"/>
...
FilePathProcessor.java
public class FilePathProcessor implements Processor {
...
#Override
public void process(Exchange exchange) throws Exception {
List<Map<String, Object>> rows = SetFilePath.getInstance().getPathList("aaaa");
SetFilePath.java
#ManagedResource
public class SetFilePath {
private static SetFilePath instance = null;
private String sourceDirectory;
private String targetDirectory;
#Autowired
private JdbcTemplate jdbcTemplate;
public static SetFilePath getInstance() {
if(instance == null) {
instance = new SetFilePath();
}
return instance;
}
Result
Message History
---------------------------------------------------------------------------------------------------------------------------------------
RouteId ProcessorId Processor
Elapsed (ms)
[fixed_processor ] [fixed_processor ] [timer://fromPollTimer?period=20000 ] [ 0]
[fixed_processor ] [_sourceDirectory ] [ref:filePathProcessor ] [ 0]
Stacktrace
---------------------------------------------------------------------------------------------------------------------------------------
java.lang.NullPointerException: null
at com.ktds.openmzn.common.bean.FilePathProcessor.process(FilePathProcessor.java:20) ~[classes/:na]
at org.apache.camel.processor.DelegateSyncProcessor.process(DelegateSyncProcessor.java:63) ~[camel-core-2.23.1.jar:2.23.1]

Answer 1

Well of course its null, because you are creating the instance yourself via the new constructor:
instance = new SetFilePath();
The #Autowired is from spring framework, and you would essentially need to use spring to create this bean for you.
There are different ways of doing this such as creating a <bean> in the XML file and then configure that on your processor via a setter <property>.
You can also let spring/camel create the bean instance instead of the new constructor, but this requires a bit of Camel API to do so
public static SetFilePath getInstance(CamelContext camel)
if (instance == null) {
instance = camel.getInjector().newInstance(SetFilePath.class);
}
Which will then via the injector create the bean instance via spring framework that does its auto-wiring.