https://github.com/javaobjects/demo_spring05_di_annotation
https://github.com/javaobjects/demo_spring05_di_annotation
Last synced: 2 months ago
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- Host: GitHub
- URL: https://github.com/javaobjects/demo_spring05_di_annotation
- Owner: javaobjects
- Created: 2019-06-20T11:59:40.000Z (almost 6 years ago)
- Default Branch: master
- Last Pushed: 2019-06-21T06:02:36.000Z (almost 6 years ago)
- Last Synced: 2025-01-28T03:17:16.968Z (4 months ago)
- Language: Java
- Size: 4.47 MB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Java-Spring基于注解的方式给依赖属性赋值
*沿用上一个项目*
1. 注释掉属性的set/get方法，并运行测试，如图所示测试失败
**结论：** 根据类型自动装配还是需要配置属性的get/set方法
2. 还原被注释掉的属性的set/get方法
3. 新建一个Java Project命名为 demo_spring05_di_annotation
4. 导入对应的jar包
5. 写对应层的类 以及配置beans.xml
**MyController**
```
package test;
public class MyController {
private MyServiceIfac service;
public MyController(MyServiceIfac myService)
{
this.service = myService;
}
public void login()
{
System.out.println("MyController login........");
service.serviceLogin();
}
}
```
**MyDao**
```
package test;
public class MyDao implements MyDaoIfac {
/* (non-Javadoc)
*
Title: queryUserByNameAndPwd
* Description:
* @see test.MyDaoIfac#queryUserByNameAndPwd()
*/
@Override
public void queryUserByNameAndPwd()
{
System.out.println("MyDao queryUserByNameAndPwd");
}
}
```
**MyDaoIfac**
```
package test;
public interface MyDaoIfac {
void queryUserByNameAndPwd();
}
```
**MyService**
```
package test;
public class MyService implements MyServiceIfac {
private MyDaoIfac dao;//MyService依赖MyDao
/**
* 为咯给属性赋值 就在属性所在的
* 类里面设置一个构造方法
* 并且该构造方法接收一个该属性类开的参数
*
Title:
* Description:
* @param myDao
*/
public MyService(MyDaoIfac myDao)
{
this.dao = myDao;
}
/* (non-Javadoc)
* Title: serviceLogin
* Description:
* @see test.MyServiceIfac#serviceLogin()
*/
@Override
public void serviceLogin() {
System.out.println("MyService serviceLogin()......");
dao.queryUserByNameAndPwd();
}
}
```
**MyService**
```
package test;
public class MyService implements MyServiceIfac {
private MyDaoIfac dao;//MyService依赖MyDao
/**
* 为咯给属性赋值 就在属性所在的
* 类里面设置一个构造方法
* 并且该构造方法接收一个该属性类开的参数
*
Title:
* Description:
* @param myDao
*/
public MyService(MyDaoIfac myDao)
{
this.dao = myDao;
}
/* (non-Javadoc)
* Title: serviceLogin
* Description:
* @see test.MyServiceIfac#serviceLogin()
*/
@Override
public void serviceLogin() {
System.out.println("MyService serviceLogin()......");
dao.queryUserByNameAndPwd();
}
}
```
**MyServiceIfac**
```
package test;
public interface MyServiceIfac {
void serviceLogin();
}
```
**Test测试类**
```
package test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) {
//实例化spring容器及bean
ApplicationContext act = new ClassPathXmlApplicationContext("beans.xml");
// 得到的是此处的controller
//
//
//
MyController c = (MyController) act.getBean("controller");
c.login();
}
}
```
**beans.xml**
```
```
6. 详细配置
+ 引入刚刚忘记引入的jar包
+ 为对应的类写入头（戴帽子）
**MyController**
```
package test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
@Controller
public class MyController {
@Autowired//自动装配的意思 默认根据类型装配
private MyServiceIfac service;
/**
* 如果有一个类不知道属于哪一层的话就写@Component 表示组件的意思
*
Title: login
* Description:
*/
// public MyController(MyServiceIfac myService)
// {
// this.service = myService;
// }
public void login()
{
System.out.println("MyController login........");
service.serviceLogin();
}
}
```
**MyDao**
```
package test;
import org.springframework.stereotype.Repository;
//又有接口又有实现类 帽子给实现类带
@Repository
public class MyDao implements MyDaoIfac {
/* (non-Javadoc)
*
Title: queryUserByNameAndPwd
* Description:
* @see test.MyDaoIfac#queryUserByNameAndPwd()
*/
@Override
public void queryUserByNameAndPwd()
{
System.out.println("MyDao queryUserByNameAndPwd");
}
}
```
**MyDaoIfac**
```
package test;
public interface MyDaoIfac {
void queryUserByNameAndPwd();
}
```
**MyService**
```
package test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;//这是一个注解
@Service
public class MyService implements MyServiceIfac {
@Autowired
private MyDaoIfac dao;//MyService依赖MyDao
/**
* 为咯给属性赋值 就在属性所在的
* 类里面设置一个构造方法
* 并且该构造方法接收一个该属性类开的参数
*
Title:
* Description:
* @param myDao
*/
// public MyService(MyDaoIfac myDao)
// {
// this.dao = myDao;
// }
/* (non-Javadoc)
* Title: serviceLogin
* Description:
* @see test.MyServiceIfac#serviceLogin()
*/
@Override
public void serviceLogin() {
System.out.println("MyService serviceLogin()......");
dao.queryUserByNameAndPwd();
}
}
```
**MyServiceIfac**
```
package test;
public interface MyServiceIfac {
void serviceLogin();
}
```
**Test类**
```
package test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) {
//实例化spring容器及bean
ApplicationContext act = new ClassPathXmlApplicationContext("beans.xml");
// 得到的是此处的controller
//
//
//
MyController c = (MyController) act.getBean("myController");
c.login();
}
}
```
**beans.xml**
```
```
7. 测试;如图所示，测试成功;
**备注：**
```
每一个类至少要有一个空的构造方法
使用注解的方式给依赖属性赋值非常方便：
1.不需要在xml文件中注册bean了；
2.不需要提供属性的setter/getter方法了；
如何使用注解开发：
1.导入aop相关的包
aop aspect
2.在xml文件中开启全包扫描：
3.编写完bean的代码后，给bean带上帽子：@Service @Controller @Repository @Component
4.还要给依赖的属性带上帽子： @Autowired @Resource
建议大家使用框架的时候后专心使用框架API，不要一边使用框架API，一边使用JavaAPI，所以使用@Autowired
@Autowired 默认按类型装配，
@Resource默认按名称装配，当找不到与名称匹配的bean才会按类型装配。
```
**以上就是我关于 Java-Spring基于注解的方式给依赖属性赋值 知识的整理与总结 另附上[源码地址](https://github.com/javaobjects/demo_spring05_di_annotation)**
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