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Spring的属性依赖检查

2012-12-27 10:40 by Rollen Holt, ... 阅读, ... 评论, 收藏, 编辑

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

<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="CustomerBean" class="com.mkyong.common.Customer" >
		<property name="action" value="buy" />
	</bean>
 
	<bean id="PersonBean" class="com.mkyong.common.Person">
		<property name="name" value="mkyong" />
		<property name="address" value="address ABC" />
		<property name="age" value="29" />
	</bean>
 
</beans>

  

2. simple dependency checking

<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="CustomerBean" class="com.mkyong.common.Customer" 
         dependency-check="simple">
 
		<property name="person" ref="PersonBean" />
		<property name="action" value="buy" />
	</bean>
 
	<bean id="PersonBean" class="com.mkyong.common.Person">
		<property name="name" value="mkyong" />
		<property name="address" value="address ABC" />
		<property name="age" value="29" />
	</bean>
 
</beans>

  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

<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="CustomerBean" class="com.mkyong.common.Customer" 
         dependency-check="objects">
 
		<property name="action" value="buy" />
		<property name="type" value="1" />
	</bean>
 
	<bean id="PersonBean" class="com.mkyong.common.Person">
		<property name="name" value="mkyong" />
		<property name="address" value="address ABC" />
		<property name="age" value="29" />
	</bean>
 
</beans>

  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

<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="CustomerBean" class="com.mkyong.common.Customer" 
         dependency-check="all">
 
		<property name="action" value="buy" />
	</bean>
 
	<bean id="PersonBean" class="com.mkyong.common.Person">
		<property name="name" value="mkyong" />
		<property name="address" value="address ABC" />
		<property name="age" value="29" />
	</bean>
 
</beans>

  

Global default dependency checking:

default-dependency-check="all"
<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" 
	default-dependency-check="all">
 
	<bean id="CustomerBean" class="com.mkyong.common.Customer">
		<property name="action" value="buy" />
		<property name="type" value="1" />
	</bean>
 
	<bean id="PersonBean" class="com.mkyong.common.Person">
		<property name="name" value="mkyong" />
		<property name="address" value="address ABC" />
		<property name="age" value="29" />
	</bean>
 
</beans>