How do I dissable Spring's Autowiring of specific fields in a class?-CodePudding

Below is a class which uses the @Configuration annotation to create a Bean. I am slowly introducing Spring into a legacy Java application. I don't want to Spring-ify everything all at once - that would be crazy. I thought I'd start with one of the commonly used utility classes and I don't want Spring to create Beans for the three fields below (Enumerator, RandomDataGenerator, AliasMethodFactory). How do I turn off Autowiring for those fields? Spring is currently complaining that it can't find Beans for those (it's obviously trying to auto-wire them).

@Configuration
public class CustomRandom {

    private Enumerator enumerator;
    private RandomDataGenerator rDataGenerator;
    private AliasMethodFactory amf;

    @Bean
    @Primary
    public static CustomRandom buildRandom() {
        return new CustomRandom(
                new Enumerator(),
                new RandomDataGenerator(
                        new MersenneTwister(System.currentTimeMillis() * Thread.currentThread().getId())
                ),
                new AliasMethodFactory()
        );
    }

CodePudding user response：

Seperate the class for the Bean and the Configuration of the Bean. Like this

@Configuration
public class CustomRandomConfiguration
{
    @Bean
    @Primary
    public static CustomRandom buildRandom()
    {
        return new CustomRandom(
            new Enumerator(),
            new RandomDataGenerator(
                new MersenneTwister(System.currentTimeMillis() * Thread.currentThread().getId())
            ),
            new AliasMethodFactory()
        );
    }
}

and the bean:

public class CustomRandom
{

    private Enumerator enumerator;
    private RandomDataGenerator rDataGenerator;
    private AliasMethodFactory amf;

    public CustomRandom(Enumerator enumerator, RandomDataGenerator rDataGenerator, AliasMethodFactory amf)
    {
        this.enumerator = enumerator;
        this.rDataGenerator = rDataGenerator;
        this.amf = amf;
    }
}

CodePudding user response：

If I'm not mistaken you have created a all-argument constructor in your CustomRandom class. That's your issue. When Spring try to initialize this class it will only see one way, which is create the class using this all-argument constructor.

The fix is very straightforward. Add no-argument constructor to CustomRandom.

@Configuration
public class CustomRandom {

    private Enumerator enumerator;
    private RandomDataGenerator rDataGenerator;
    private AliasMethodFactory amf;

    @Autowired // This is not needed, yet its better to add it show your intent
    public CustomRandom() {}

    @Bean
    @Primary
    public static CustomRandom buildRandom() {
        return new CustomRandom(
                new Enumerator(),
                new RandomDataGenerator(
                        new MersenneTwister(System.currentTimeMillis() * Thread.currentThread().getId())
                ),
                new AliasMethodFactory()
        );
    }