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前言
通过构造方法实例化
通过动态工厂实例化
通过实例工厂实例化
通过 FactoryBean 实例化
RumenzA 实体类
package com.rumenz;
public class RumenzA {
private String id;
private String name;
public static RumenzA createRumenzA(){RumenzA rumenzA=new RumenzA();
rumenzA.setId("123");
rumenzA.setName("入门小站");
return rumenzA;
}
public RumenzA() {System.out.println("RumenzA 无参构造方法");
}
public RumenzA(String id) {
this.id = id;
System.out.println("ID 构造方法");
}
// set get 省略
}
构造方法
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
https://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="rumenz" class="com.rumenz.RumenzA" />
<bean id="rumenz1" class="com.rumenz.RumenzA">
<constructor-arg name="id" value="1"/>
</bean>
</beans>DemoApplication.java
package com.rumenz;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class DemoApplication {public static void main(String[] args) {ClassPathXmlApplicationContext ca=new ClassPathXmlApplicationContext("beans.xml");
RumenzA rumenzA=(RumenzA)ca.getBean("rumenz");
}
}输入
xxx.DefaultListableBeanFactory - Creating shared instance of singleton bean 'rumenz'
RumenzA 无参构造方法
xxx.DefaultListableBeanFactory - Creating shared instance of singleton bean 'rumenz1'
ID 构造方法动态工厂
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
https://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="rFactory" class="com.rumenz.RumenzFactory" factory-method="rumenzFactory"/>
<bean id="rFactory1" class="com.rumenz.RumenzFactory" factory-method="rumenzFactory">
<constructor-arg name="id" value="111"/>
</bean>
</beans>RumenzFactory 工厂类
package com.rumenz;
public class RumenzFactory {
// 静态方法
public static RumenzA rumenzFactory(){return new RumenzA();
}
public static RumenzA rumenzFactory(String id){return new RumenzA(id);
}
}DemoApplication.java
package com.rumenz;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class DemoApplication {public static void main(String[] args) {ClassPathXmlApplicationContext ca=new ClassPathXmlApplicationContext("beans.xml");
}
}输入
xxx.DefaultListableBeanFactory - Creating shared instance of singleton bean 'rFactory'
RumenzA 无参构造方法
xxx.DefaultListableBeanFactory - Creating shared instance of singleton bean 'rFactory1'
ID 构造方法实例工厂实例化
<?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
https://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="rFactory" class="com.rumenz.RumenzFactory" />
<bean id="rumenz" factory-bean="rFactory" factory-method="rumenzFactory"></bean>
<bean id="rumenz1" factory-bean="rFactory" factory-method="rumenzFactory">
<constructor-arg name="id" value="666"></constructor-arg>
</bean>
</beans>RumenzFactory.java
package com.rumenz;
public class RumenzFactory {
// 不能用静态方法
public RumenzA rumenzFactory(){return new RumenzA();
}
public RumenzA rumenzFactory(String id){return new RumenzA(id);
}
}DemoApplication.java
package com.rumenz;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class DemoApplication {public static void main(String[] args) {ClassPathXmlApplicationContext ca=new ClassPathXmlApplicationContext("beans.xml");
//RumenzA rumenzA=(RumenzA)ca.getBean("rFactory1");
}
}输入
xxx.DefaultListableBeanFactory - Creating shared instance of singleton bean 'rumenz'
RumenzA 无参构造方法
xxx.DefaultListableBeanFactory - Creating shared instance of singleton bean 'rumenz1'
ID 构造方法通过 FactoryBean 实例化
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
https://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="rumenz-by-factoryBean" class="com.rumenz.RumenzAFactoryBean"/>
</beans>RumenzAFactoryBean.java
package com.rumenz;
import org.springframework.beans.factory.FactoryBean;
public class RumenzAFactoryBean implements FactoryBean {
@Override
public Object getObject() throws Exception {return RumenzA.createRumenzA();
}
@Override
public Class<?> getObjectType() {return RumenzA.class;}
}
DemoApplication.java
package com.rumenz;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class DemoApplication {public static void main(String[] args) {ClassPathXmlApplicationContext ca=new ClassPathXmlApplicationContext("beans.xml");
RumenzA rumenzA=(RumenzA)ca.getBean("rumenz-by-factoryBean");
}
}输入 / 异步加载 bean
xxx.DefaultListableBeanFactory - Creating shared instance of singleton bean 'rumenz-by-factoryBean'
RumenzA 无参构造方法最初
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正文完
