Spring simple case (dependency injection)_01

Spring ioc dependency injection annotations

The following is the configuration file, which configures the scan path of spring. It does not work if this annotation is not configured.

package com.expect.oa.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan("com.expect.oa.*")
//@ComponentScan(basePackages={"com.expect.oa.DI.*","com.expect.oa.DI2.*"})
//Multiple packages can be written like this, which is equivalent to configuring automatic scanning in XML
public class SpringConfig {

}

Here is an interface:

package com.expect.oa.DI.interfaces;

public interface InterA {

	void action1 ();
	
}

The following declares a simple class that inherits the above interface:

package com.expect.oa.DI;

import org.springframework.stereotype.Component;

import com.expect.oa.DI.interfaces.InterA;

@Component("interAImpl")
//@Named("interAImpl") has the same effect
public class CompA implements InterA{

	@Override
	public void action1() {
		// TODO Auto-generated method stub
		System.out.println("spring DI");
	}

}

Here is the test code:

package com.expect.oa.test;

import javax.annotation.Resource;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.expect.oa.DI.interfaces.InterA;
import com.expect.oa.config.SpringConfig;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {SpringConfig.class})
public class TestSpringDI {

	//Personal suggestion to name each component.
	@Resource(name="interAImpl")
	//@Autowired the same effect
	InterA aService;
	
	// here is the test dependency injection
	@Test
	public void testDI() {
		aService.action1 ();
	}

}

Succeed, simple.

Spring simple case (dependency injection)_01

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