Spring支持4种依赖检查：默认的是none

• • none – No dependency checking.
  • simple – If any properties of primitive type (int, long,double…) and collection types (map, list..) have not been set, UnsatisfiedDependencyException will be thrown.
  • objects – If any properties of object type have not been set, UnsatisfiedDependencyException will be thrown.

 　　　　all – If any properties of any type have not been set, an UnsatisfiedDependencyException will be thrown.

举个例子：

public class Customer {	private Person person;	private int type;	private String action; 	//getter and setter methods}

　　

public class Person {	private String name;	private String address;	private int age; 	//getter and setter methods	}

　　

1. none dependency checking

　　

2. simple dependency checking

　　注意此处type字段故意没有设置，这样会出现UnsatisfiedDependencyException

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'CustomerBean' defined in class path resource [config/Spring-Customer.xml]: Unsatisfied dependency expressed through bean property 'type': Set this property value or disable dependency checking for this bean.

3. objects dependency checking

　　此处故意没有设置”person“属性，会出现UnsatisfiedDependencyException

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'CustomerBean' defined in class path resource [config/Spring-Customer.xml]: Unsatisfied dependency expressed through bean property 'person': Set this property value or disable dependency checking for this bean.

4. all dependency checking

　　

Global default dependency checking：

default-dependency-check="all"