DI

0.常见2种注入方式

0.1 构造方法注入
0.2 setter方法注入

1.构造方法注入

1.1 实例化对象注入
    public void testSave4() {
        UserDao userDao = new UserDaoImpl("DI");
        userDao.save();
    }
1.2 Spring注入
    <bean id="userDao" class="com.boomsecret.ioc.UserDaoImpl">
        <constructor-arg index="0" type="java.lang.String" value="DI"/>
    </bean>

    public void testSave5() {
        String configPath = "com/boomsecret/ioc/bean.xml";
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext(configPath);
        UserDao userDao = applicationContext.getBean("userDao", UserDao.class);
        userDao.save();
    }

2.setter方法注入

2.1 直接调用setter方法注入
    public void testSave4() {
        UserDaoImpl userDaoImpl = new UserDaoImpl();
        userDaoImpl.setDefaultValue("DI");
        userDaoImpl.save();
    }
2.2 Spring注入
    <bean id="userDao" class="com.boomsecret.ioc.UserDaoImpl">
        <property name="defaultValue" value="DI"></property>
    </bean>
    public void testSave5() {
        String configPath = "com/boomsecret/ioc/bean.xml";
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext(configPath);
        UserDao userDao = applicationContext.getBean("userDao", UserDao.class);
        userDao.save();
    }