NoSuchBeanDefinitionException with list of string - pom.xml

Question

I have problem with NoSuchBeanDefinitionException.

@Component
public class Monitor {

    private List<String> urlsToCheckState;

    @Autowired
    ServerConfig config; 

    public Monitor(config config, List<String> urlsToCheckState){
       urlsToCheckState.add("state1");
    }

I understand that Spring can not find Bean which return list of String. I was looking for solution but coudn't find anything which solve my problem. Here is my error.

Error creating bean with name 'Monitor' defined in file [C:\Users]: Unsatisfied dependency expressed through constructor parameter 1; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'java.util.List' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}

score 0 · Answer 1 · answered Apr 12 '18 at 10:11

0

Because you have not used @Autowired on urlsToCheckState. You have to inject it using constructor injection.

Inside your component create a constructor as below:-

Monitor(List<String> urlsToCheckState){
   this.urlsToCheckState = urlsToCheckState;
}

This way you would be able to inject using constructor.

answered Apr 12 '18 at 10:11

Vinay Prajapati

7,199
9
45
86

Unfortunately it didn't help - `Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [Monitor]: No default constructor found; nested exception is java.lang.NoSuchMethodException: Monitor.()` then I added deafult constructor and have another exception `java.lang.NullPointerException: null at Monitor.(Monitor.java:135) ~[classes/:na]` – Tom Apr 12 '18 at 10:18
okay! Have you declared List urlsToCheckState as a bean anywhere in a config file. Because looks like you haven't declared a bean anywhere? – Vinay Prajapati Apr 12 '18 at 10:22
I did not. When I was looking for an answer I saw some information that I should declared List of String in config file but I do know how and where should I make it – Tom Apr 12 '18 at 10:24

score 0 · Accepted Answer · answered Apr 12 '18 at 10:24

0

To have dependencies injected at construction you need to have your constructor marked with the @Autowired annoation like below.

@Autowired
Monitor(List<String> urlsToCheckState){
   this.urlsToCheckState = urlsToCheckState;
}

Of course before injection you must create instance of bean urlsToCheckState.

answered Apr 12 '18 at 10:24

Bartek M.

26
5

How to do it? It is just simple list of strings – Tom Apr 12 '18 at 10:26
You can do this that way: https://stackoverflow.com/questions/2416056/how-to-define-a-list-bean-in-spring – Bartek M. Apr 12 '18 at 10:35
Should I add it to pom.xml? – Tom Apr 12 '18 at 10:36
You should add it to your configuration file. – Bartek M. Apr 12 '18 at 10:39

NoSuchBeanDefinitionException with list of string - pom.xml

2 Answers2