>Spring注入是指在启动Spring容器加载bean配置的时候，完成对变量的赋值行为
>常用的两种注入方式：

- 设值注入

    Spring入门——（四、Spring注入）_编程

 

- 构造注入

                Spring入门——（四、Spring注入）_编程_02

示例：

dao层：

public interface InjectionDao {
    void save(String arg);
}
      

daoImpl层：

public class InjectionDaoImpl implements InjectionDao {
    @Override
    public void save(String arg) {
        System.out.print("保存数据"+arg);
    }
}

   service层：

public interface InjectionService {
    void sava(String arg);
}

   serviceImpl层：

public class InjectionServiceImpl implements InjectionService {

    private InjectionDao injectionDao;

    public void setInjectionDao(InjectionDao injectionDao) {
        this.injectionDao = injectionDao;
    }

    //模拟业务操作
    @Override
    public void sava(String arg) {
        System.out.print("Service接受参数："+arg);
        arg = arg + ";" +this.hashCode();
        injectionDao.save(arg);
    }
}

   main测试：

@RunWith(BlockJUnit4ClassRunner.class)
public class Test extends UnitTestBase{
    public TestInjection(){
        super("classpath:spring-injection.xml");
    }

    @Test
    public void testSetter(){
        InjectionService is = super.getBean("injectionService");
        is.sava("这是要保存的数据");
    }

    @Test
    public void testCons(){
        InjectionService is = super.getBean("injectionService");
        is.sava("这是要保存的数据");
    }
}

spring注入配置xml：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans">
    <bean id="InjectionService" class="InjectionServiceImpl">
        <property name="InjectionDao" ref="InjectionDao"/>
    </bean>
    <bean id="InjectionDao" class="InjectionDaoImpl"/>
</beans>

测试结果：

 

Service接受参数：这是要保存的数据
        保存数据：这是要保存的数据：912127037