Spring Boot Autowired null

Question

I have several classes in a Spring Boot project, some work with @Autowired, some do not. Here my code follows:

Application.java (@Autowired works):

package com.example.myproject;

@ComponentScan(basePackages = {"com.example.myproject"})
@Configuration
@EnableAutoConfiguration
@EnableJpaRepositories(basePackages = "com.example.myproject.repository")
@PropertySource({"classpath:db.properties", "classpath:soap.properties"})
public class Application {

@Autowired
private Environment environment;

public static void main(String[] args) {
    SpringApplication.run(Application.class);
}

@Bean
public SOAPConfiguration soapConfiguration() {
    SOAPConfiguration SOAPConfiguration = new SOAPConfiguration();
    SOAPConfiguration.setUsername(environment.getProperty("SOAP.username"));
    SOAPConfiguration.setPassword(environment.getProperty("SOAP.password"));
    SOAPConfiguration.setUrl(environment.getProperty("SOAP.root"));
    return SOAPConfiguration;
}

HomeController (@Autowired works):

package com.example.myproject.controller;

@Controller
class HomeController {

    @Resource
    MyRepository myRepository;

MyService (@Autowired does not work):

package com.example.myproject.service;

@Service
public class MyServiceImpl implements MyService {

    @Autowired
    public SOAPConfiguration soapConfiguration; // is null

    private void init() {
    log = LogFactory.getLog(MyServiceImpl.class);
    log.info("starting init, soapConfiguration: " + soapConfiguration);
    url = soapConfiguration.getUrl(); // booom -> NullPointerException

I do not get the SOAPConfiguration but my application breaks with a null pointer exception when I try to access it.

I have already read many Threads here and googled around, but did not find a solution yet. I tried to deliver all necessary information, please let me know if anything misses.

From where are you calling the `init` method? I suspect the constructor. — M. Deinum, Oct 20 '14 at 08:49
HomeController.update creates a new MyServiceImpl and calls myService.update which calls its init method. — dexBerlin, Oct 20 '14 at 08:53
If you are creating new instances yourself spring will not autowire them, spring will only inject into bean instances it knows about. Why do you need a new instance each time? — M. Deinum, Oct 20 '14 at 08:55
HomeController is not a bean instance too, but injection works. — dexBerlin, Oct 20 '14 at 08:59
Yes it is... Due to the `@Controller` and the `@ComponentScan` it is automatically detected and managed. — M. Deinum, Oct 20 '14 at 09:00

score 12 · Accepted Answer · answered Oct 20 '14 at 08:53

12

I guess you call init() before the autowiring takes place. Annotate init() with @PostConstruct to make it call automatically after all the spring autowiring.

EDIT: after seeing your comment, I guess you are creating it using new MyServiceImpl(). This takes away the control of the MyServiceImpl from Spring and gives it to you. Autowiring won't work in those case

answered Oct 20 '14 at 08:53

sinujohn

2,506
3
21
26

I added the @PostContruct annotation, but soapConfiguration is still null. – dexBerlin Oct 20 '14 at 08:57

score 2 · Answer 2 · answered Oct 20 '14 at 08:53

2

Did you created a bean for the class SOAPConfiguration in any of your configuration classes? If you want to autowire a class in your project, you need to create a bean for it. For example,

@Configuration
public class SomeConfiguration{

    @Bean
    public SOAPConfiguration createSOAPConfiguration(){

        return new SOAPConfiguration();
    }

}

public class SomeOtherClass{

    @Autowired
    private SOAPConfiguration soapConfiguration;
}

answered Oct 20 '14 at 08:53

furkan3ayraktar

543
10
18

The Application.java should do that? As in my explanation? – dexBerlin Oct 20 '14 at 08:55
Are you sure the method on your Application.java called for SOAPConfiguration? – furkan3ayraktar Oct 20 '14 at 09:00

Spring Boot Autowired null

2 Answers2