https://github.com/javaobjects/demo_spring04_di_three
https://github.com/javaobjects/demo_spring04_di_three
Last synced: 2 months ago
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- Host: GitHub
- URL: https://github.com/javaobjects/demo_spring04_di_three
- Owner: javaobjects
- Created: 2019-06-19T18:07:10.000Z (almost 6 years ago)
- Default Branch: master
- Last Pushed: 2019-10-08T08:47:20.000Z (over 5 years ago)
- Last Synced: 2025-01-28T03:17:17.375Z (4 months ago)
- Language: Java
- Size: 3.05 MB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Java-Spring依赖属性的构造函数注入
1. 新建一个Java Project
2. Java工程导jar包
+ 创建一个lib文件夹
**如图所示新建完成**
+ 导入jar包
+ 新建或导入配置文件
**beans.xml**
```
```
3. 新建test/MyController test/MyService test/MyDao
**MyController**
```
package test;
public class MyController {
private MyService service;
public MyController(MyService myService)
{
this.service = myService;
}
public void login()
{
System.out.println("MyController login........");
service.serviceLogin();
}
}
```
**MyService**
```
package test;
public class MyService {
private MyDao 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(MyDao myDao)
{
this.dao = myDao;
}
public void serviceLogin() {
System.out.println("MyService serviceLogin()......");
dao.queryUserByNameAndPwd();
}
}
```
**MyDao**
```
package test;
public class MyDao {
public void queryUserByNameAndPwd()
{
System.out.println("MyDao queryUserByNameAndPwd");
}
}
```
4. 构造函数配置（亮点加重点）
**beans.xml**
```
```
5. 新建测试类测试
**Test.java**
```
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();
}
}
```
**如图所示测试成功**
#### 总结
属性注入的两种方式：
1.构造函数注入：
//需要在类中定义构造方法，并且接收参数，便于给属性赋值
```
public MyController(MyService myService)
{
this.service=myService;
}
public MyService(MyDao myDao)
{
this.dao=myDao;
}
```
//接着在配置文件中对bean进行配置，特别注意给构造方法中的参数赋值
```
```
2.属性的setter方法注入
```
//需要提供属性的setter方法
//需要在配置bean的时候使用标签给属性赋值
```
**以上就是我对于 Java-Spring依赖属性的构造函数注入 知识点整理的全部内容** 另附[源码](https://github.com/javaobjects/demo_spring04_di_three)
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