Java基础之Spring5的核心之一IOC容器

<!--创建对象、自动装配
    bean标签里面的autowire属性：
        属性值：byName:根据属性名字注入值，id的值必须与类里面的属性名称一样
              byType:根据属性的类型注入值。
-->
<bean id="employee" class="tianfei.Spring5.autowire.Employee" autowire="byType">
    <!--手动装配-->
    <!--<property name="dept" ref="dept"></property>-->
</bean>

public class User {
    
        private Integer id;
        private String name;
    
        public User() {
        }
    
        public User(Integer id, String name) {
            this.id = id;
            this.name = name;
        }
    
        public void setId(Integer id) {
            this.id = id;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public void setAddress(String address) {
            this.address = address;
        }
    }

<!--1、配置User对象
       id：为创建后的对象名，可自取
       class：为类的全路径
  -->
<bean id="user" class="tianfei.Spring5.User">
    <!--2、通过set方法注入属性
            通过property注入属性
                 name ：类里面的属性
                 value ：类里面属性对应的值
    -->
    <property name="id" value="1"></property>
    <property name="name" value="田飞"></property>

    <!--通过有参构造注入属性-->
    <constructor-arg name="id" value="2"></constructor-arg>
    <constructor-arg name="name" value="张三"></constructor-arg>

    <!--通过p名称空间注入属性
         使用前，需在xml标签属性中加入：xmlns:p="Http://www.springframework.org/schema/p"
    -->
    <bean id="user" class="tianfei.Spring5.User" p:id="1" p:name="李四"></bean>
</bean>

public class testDemo {
    @Test
    public void test() {
        //1、加载Spring5 的xml配置文件
        ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");

        //2、获取配置创建的对象
        User user = context.getBean("usera", User.class);

        System.out.println(user);
    }
}

<!--引入外部文件  jdbc.properties
        需在名称空间中加入：xmlns:context="http://www.springframework.org/schema/context"
    -->
    <context:property-placeholder location="classpath:jdbc.properties"></context:property-placeholder>

    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" >
        <property name="driverClassName" value="${prop.driverClassName}"></property>
        <property name="url" value="${prop.url}"></property>
        <property name="username" value="${prop.username}"></property>
        <property name="passWord" value="${prop.password}"></property>
    </bean>

prop.driverClassName=com.Mysql.jdbc.Driver
prop.url=jdbc:mysql://localhost:3306/userdb
prop.username=root
prop.password=tianfei

public interface UserDao {
          public void add();
    }
        @Controller(value = "userDaoImpl")
    public class UserDaoImpl implements UserDao {
    
        @Override
        public void add() {
            System.out.println("userdao add.......");
        }
    
        public UserDaoImpl() {
        }
    }

//value属性可以省略，如果省略则默认创建的对象名为  类名首字母小写  对象
@Service(value = "userService")
public class UserService {
    //基于注解注入基本类型数据
    @Value(value = "abc")
    private String str;

    //基于注解注入对象类型值
//    @Autowired  //根据类型注入
//    @Qualifier(value = "userDaoImpl")  //根据名称注入 需要和 Autowired 一起使用
//    private UserDao userDao;

//    @Resource   //根据类型注入
    @Resource(name = "userDaoImpl")  //根据名称注入
    private UserDao userDao;

    public void add() {
        System.out.println("service add........");
        userDao.add();
    }

    public void test() {
        System.out.println("userDao = " + userDao);
        System.out.println(str);
    }
}

public class test {
    @Test
    public void test1(){
        //测试使用注解创建对象
        //需要在mxl配置文件中配置：<context:component-scan base-package="tianfei.Spring5"></context:component-scan> ，来开启注解扫描组件
        //不需要添加set方法
        ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");

        UserService userService = context.getBean("userService", UserService.class);

        System.out.println(userService);
        userService.add();
        userService.test();
    }
    @Test
    public void test2(){
        //测试使用注解创建对象
        //不需要添加set方法
        //使用完全注解
        ApplicationContext context = new AnnotationConfigApplicationContext(SprinGConfig.class);

        UserService userService = context.getBean("userService", UserService.class);

        System.out.println(userService);
        userService.add();
        userService.test();
    }
}

@Configuration      //作为配置类，代替xml配置文件，进行完全注解开发
@ComponentScan(value = {"tianfei.Spring5"})
public class SpringConfig {
}

 public class MyBean implements FactoryBean<User> {

    //用来改变返回对象（返回的对象可以和创建的对象不一样）
    @Override
    public User getObject() throws Exception {
        return new User(1,"张三");
    }

    @Override
    public Class<?> getObjectType() {
        return null;
    }

    @Override
    public boolean isSingleton() {
        return false;
    }
}

<!--创建类的对象-->
<bean id="myBean" class="tianfei.Spring5.factorybean.MyBean"></bean>

   public class test {

    @Test
    public void testMyBean() {
        //测试 FactoryBean 工厂
        ApplicationContext context = new ClassPathXmlApplicationContext("MyBean.xml");

        Book book = context.getBean("myBean",Book.class);
        System.out.println(book);
    }
}