Autodetecting The Autowiring

The last technique in autowiring is auto-detect. In this case we tell the Spring container to uses its own brains while configuring the bean.
When we use the auto-detect setting for autowiring Spring follows the following rules to configure the bean:

1. Try and configure the bean using constructor
2. If the above step fails, then auto wire by type. 

Consider the below class. I haven't added any setter methods. Only placed the constructor.

public class CarAutoDetect implements ICar {
    private Engine combustEngine;
    private Seating leatherSeating;
    private Seating backupSeating;
    public CarAutoDetect(final Engine anyEngine, final Seating leatherSeating,
            final Seating seating) {
        this.combustEngine = anyEngine;
        this.leatherSeating = leatherSeating;
        this.backupSeating= seating;
    }
    
    @Override
    public String describe() {        
        return "Car is " + this + ", engine is " + this.combustEngine + " and seating1 is " + this.leatherSeating
        + " and seating2 is " + this.backupSeating;
    }
}

The XML configuration for the above would be:

<bean id="carAutoDetect" class="com.car.CarAutoDetect" autowire="autodetect"/>
<bean id="combustEngine" class="com.car.Engine" p:name="Combusto" />
<bean id="leatherSeating" class="com.car.Seating" p:color="red" />

The code would work and the beans will be wired.