spring学习8-纯注解

纯注解开发

pojo类

@Component
public class User {
    @Value("cong")
    private String name;

    @Override
    public String toString() {
        return "User{" +
                "name='" + name + '\'' +
                '}';
    }
}

配置类

@Configuration//声明是一个配置类
@ComponentScan("com.cong")//用于通过注解指定spring在创建容器时要扫描的包
public class SpringConfig {
}

测试

    @Test
    public void test1(){
        ApplicationContext context = new AnnotationConfigApplicationContext(SpringConfig.class);
        User user = (User) context.getBean("user");
        System.out.println(user.toString());
    }

引入其他配置文件

额外一个pojo类

public class Cat {
    private String name;

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Cat{" +
                "name='" + name + '\'' +
                '}';
    }
}

配置类

@Configuration
public class Config2 {
    //注册bean
    //默认的bean的id是方法的名字，可以通过name或者value设置别名
    //方法的返回值就是bean的class
    @Bean("cat")//(name = "cat",value = "cat2")
    public Cat getCat(){
        Cat cat = new Cat();
        cat.setName("小猫");
        return cat;
    }
}

引入其他配置文件

@Configuration//声明是一个配置类
@ComponentScan("com.cong")//用于通过注解指定spring在创建容器时要扫描的包
@Import(Config2.class)//导入其它配置类
public class SpringConfig {
}

测试

    @Test
    public void test1(){
        ApplicationContext context = new AnnotationConfigApplicationContext(SpringConfig.class);
        User user = (User) context.getBean("user");
        System.out.println(user.toString());
        Cat cat = (Cat) context.getBean("cat");
        System.out.println(cat.toString());
    }