直接上例子
引入spring以及Junite所需要的jar包
User.java
package com.bjsxt.model;
public class User {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
Userservice.java
package com.bjsxt.service;
import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.User; public class UserService {
private UserDAO userDAO;
public void add(User user) {
userDAO.save(user);
}
public UserDAO getUserDAO() {
return userDAO;
}
public void setUserDAO(UserDAO userDAO) {
this.userDAO = userDAO;
}
}
userDAO
package com.bjsxt.dao;
import com.bjsxt.model.User; public interface UserDAO {
public void save(User user);
}
userDAOimpl
package com.bjsxt.dao.impl; import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.User; public class UserDAOImpl implements UserDAO { public void save(User user) {
//Hibernate
//JDBC
//XML
//NetWork
System.out.println("user saved!");
} }
beans.xml
<?xml version="1.0" encoding="utf-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> <bean id="u" class="com.bjsxt.dao.impl.UserDAOImpl">
</bean> <bean id="userService" class="com.bjsxt.service.UserService">
<property name="userDAO" ref="u"/> </bean> </beans>
public class UserServiceTest {
@Test
public void testAdd() throws Exception {
ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml"); //读取到配置文件
UserService service = (UserService)ctx.getBean("userService"); //Spring根据配置文件将UserDAO的实现注入到userdao 然后将userdao注入到userservice
User u = new User();
u.setUsername("zhangsan");
u.setPassword("zhangsan");
service.add(u);
}
IOC 即invotion of control 控制反转 本来要由自己写的代码 自己确定的实现 由Spring容器帮我们实现
DI 即依赖注入 即依赖容器帮我们实例化我们实际要实例化的对象