依赖注入初步了解

紧耦合有依赖的写法:

class Employee {  
	Address address;  
	Employee() {  
		address = new Address();  
	}  
}  

松耦合没依赖的写法:

class Employee {  
	Address address;  
	Employee(Address address) {  
		this.address=address;  
	}  
} 

依赖注入最大的两个好处是:

• 代码松耦合, 易维护
• 易测试