Spring4.0以后提供了泛型依赖注入，开发时减少许多代码量。
Demo
开发的时候，大多数情况是对对象进行增删改查，使用泛型依赖注入将重复使用的代码全部放到一个类之中，方便以后的维护和修改。
比如对学生和老师进行添加操作，都有add方法，可以创建公共的持久层类进行add操作。
Model层
Student类：
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
| package com.spring.test.model;
import org.springframework.stereotype.Component;
@Component
public class Student {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "Student [name=" + name + "]";
}
}
|
Teacher类：
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
| package com.spring.test.model;
import org.springframework.stereotype.Component;
@Component
public class Teacher {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "Teacher [name=" + name + "]";
}
}
|
DAO持久层
泛型依赖注入将add操作放入公共的持久层类中。
定义BaseDao接口和BaseDaoImpl实现类：
BaseDao:
1
2
3
4
5
6
7
8
| package com.spring.test.dao;
public interface BaseDao<T> {
public void add(T t);
}
|
BaseDaoImpl:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
| package com.spring.test.dao.impl;
import org.springframework.stereotype.Repository;
import com.spring.test.dao.BaseDao;
@Repository
public class BaseDaoImpl<T> implements BaseDao<T> {
public void add(T t) {
System.out.println("Insert DataBase:" + t);
}
}
|
Service业务层
StudentService：
1
2
3
4
5
6
7
8
9
10
11
12
| package com.spring.test.service;
import org.springframework.stereotype.Service;
import com.spring.test.model.Student;
import com.spring.test.service.impl.BaseService;
@Service
public class StudentService extends BaseService<Student>{
}
|
TeacherService：
1
2
3
4
5
6
7
8
9
10
11
| package com.spring.test.service;
import org.springframework.stereotype.Service;
import com.spring.test.model.Teacher;
import com.spring.test.service.impl.BaseService;
@Service
public class TeacherService extends BaseService<Teacher> {
}
|
Controller表现层
MyController：
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
| package com.spring.test.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import com.spring.test.model.Student;
import com.spring.test.model.Teacher;
import com.spring.test.service.StudentService;
import com.spring.test.service.TeacherService;
@Controller
public class MyController {
@Autowired
private StudentService studentService;
@Autowired
private TeacherService teacherService;
public void add() {
Student student = new Student();
student.setName("I'm a Student");
studentService.add(student);
Teacher teacher = new Teacher();
teacher.setName("I'm a Teacher");
teacherService.add(teacher);
}
}
|
配置文件
spring-component-scan.xml：
1
2
3
4
5
6
7
8
9
10
| <?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">
<context:component-scan base-package="com.spring.test"/>
</beans>
|
测试
1
2
3
4
5
6
7
8
9
10
11
12
13
14
| package com.spring.test.test;
import org.springframework.context.ApplicationContext;
public class Main {
public static void main(String[] args) {
ApplicationContext ctx = new ClassPathXmlApplicationContext(
"spring-component-scan.xml");
MyController p = (MyController) ctx.getBean("myController");
p.add();
}
}
|
结果:
Insert DataBase:Student [name=I’m a Student]
Insert DataBase:Teacher [name=I’m a Teacher]
```
