guice 构造注入 循环依赖会报错

Tried proxying dyyx.cycle.failcase.ServiceA to support a circular dependency

可使用 字段注入 或者 Provider 


构造注入

import javax.inject.Inject;
import javax.inject.Singleton;

import com.google.inject.Guice;
import com.google.inject.Injector;


@Singleton
class ServiceA{
	
	private final ServiceB serviceB;
	
    // 构造函数注入 循环依赖报错 
	// Tried proxying dyyx.cycle.failcase.ServiceA to support a circular dependency, but it is not an interface.
	@Inject
	public ServiceA(ServiceB serviceB) {
		this.serviceB = serviceB;
	}
		
	public void hello() {
		System.out.println("ServiceA say hello,serviceA="+this+",serviceB="+serviceB);
	}
	
}

@Singleton
class ServiceB{
	private final ServiceA serviceA;

	@Inject
	public ServiceB(ServiceA serviceA) {
		this.serviceA = serviceA;
	}
	public void hello() {
		System.out.println("ServiceB say hello,serviceB="+this+",serviceA="+serviceA);
	}
}


@Singleton
public class CycleFailDemo {

	@Inject
	private ServiceA serviceA;
	@Inject
	private ServiceB serviceB;

	public static void main(String[] args) throws Exception {	
		Injector injector = Guice.createInjector();
		CycleFailDemo cycleFailDemo = injector.getInstance(CycleFailDemo.class);
		cycleFailDemo.hello();
	}

	public void hello() {
		serviceA.hello();
		serviceB.hello();
	}
}

字段注入

import javax.inject.Inject;
import javax.inject.Singleton;

import com.google.inject.Guice;
import com.google.inject.Injector;


@Singleton
class ServiceA{
	
	@Inject
	private ServiceB serviceB;
	
	public void hello() {
		System.out.println("ServiceA say hello,serviceA="+this+",serviceB="+serviceB);
	}
	
}

@Singleton
class ServiceB{
	
	@Inject
	private ServiceA serviceA;
	
	public void hello() {
		System.out.println("ServiceB say hello,serviceB="+this+",serviceA="+serviceA);
	}
}


@Singleton
public class CycleSuccess1Demo {
	@Inject
	private ServiceA serviceA;
	@Inject
	private ServiceB serviceB;

	public static void main(String[] args) throws Exception {
		Injector injector = Guice.createInjector();
		CycleSuccess1Demo cycleFailDemo = injector.getInstance(CycleSuccess1Demo.class);
		cycleFailDemo.hello();	
	}

	public void hello() {
		serviceA.hello();
		serviceB.hello();
	}
}

Provider



import javax.inject.Inject;
import javax.inject.Provider;
import javax.inject.Singleton;

import com.google.inject.Guice;
import com.google.inject.Injector;


@Singleton
class ServiceA{
	
	private final Provider<ServiceB> serviceB;
	
    // 构造函数注入 循环依赖 使用 Provider
	@Inject
	public ServiceA(final Provider<ServiceB> serviceB) {
		this.serviceB = serviceB;
	}
		
	public void hello() {
		System.out.println("ServiceA say hello,serviceA="+this+",serviceB="+serviceB);
	}
	
}

@Singleton
class ServiceB{
	private final Provider<ServiceA> serviceA;

	@Inject
	public ServiceB(final Provider<ServiceA> serviceA) {
		this.serviceA = serviceA;
	}
	public void hello() {
		System.out.println("ServiceB say hello,serviceB="+this+",serviceA="+serviceA);
	}
}


@Singleton
public class CycleSuccess2Demo {

	@Inject
	private ServiceA serviceA;
	@Inject
	private ServiceB serviceB;

	public static void main(String[] args) throws Exception {	
		Injector injector = Guice.createInjector();
		CycleSuccess2Demo cycleFailDemo = injector.getInstance(CycleSuccess2Demo.class);
		cycleFailDemo.hello();
	}

	public void hello() {
		serviceA.hello();
		serviceB.hello();
	}
}



完整代码
https://gitee.com/dyyx/hellocode/tree/master/demo/guicedemo/src/main/java/dyyx/cycle