28 Spring通过自动检测(AutoDetect)自动装配

在Spring，“通过自动检测自动装配”，“通过构造函数自动装配”是指选，如果默认构造函数(参数与任何数据类型)，以其他方式使用“按类型自动装配”。
请参见Spring “通过自动检测自动装配”的一个例子。自动装配(对"panda" bean 的实现基地)的“kungfu” Bean 到 “panda”，通过构造函数或类型。

1. AutoDetect – 按构造函数装配

如果默认的构造函数提供，自动检测将构造自动装配。

package com.gp6.autoAssemblyBean.AutoDetect;

public class KungFu {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Language [name=" + name + "]";
    }

}

package com.gp6.autoAssemblyBean.AutoDetect;

public class Panda {
    private KungFu kungfu;

    public Panda(KungFu kungfu) {
        System.out.println("autowiring by constructor");
        this.kungfu = kungfu;
    }

    public KungFu getKungfu() {
        return kungfu;
    }

    public void setKungfu(KungFu kungfu) {
        System.out.println("autowiring by type");
        this.kungfu = kungfu;
    }

}

<?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="panda" class="com.gp6.autoAssemblyBean.AutoDetect.Panda" autowire="autodetect" />
        
    <bean id="kungfu" class="com.gp6.autoAssemblyBean.AutoDetect.KungFu" >
        <property name="name" value="Tai Ji" />
    </bean>

</beans>

package com.gp6.autoAssemblyBean.AutoDetect;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext(
                "com/gp6/autoAssemblyBean/AutoDetect/applicationContext.xml");

        Panda panda = (Panda) context.getBean("panda");
        System.out.println(panda);
    }
}

输出

autowiring by constructor
com.gp6.autoAssemblyBean.AutoDetect.Panda@48e61a35

2. AutoDetect – 按类型装配

如果没有找到默认的构造函数，自动检测将按类型选择装配。

package com.gp6.autoAssemblyBean.AutoDetect.type;

public class KungFu {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Language [name=" + name + "]";
    }

}

package com.gp6.autoAssemblyBean.AutoDetect.type;

public class Panda {
    private KungFu kungfu;

    public KungFu getKungfu() {
        return kungfu;
    }

    public void setKungfu(KungFu kungfu) {
        System.out.println("autowiring by type");
        this.kungfu = kungfu;
    }

}

<?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="panda" class="com.gp6.autoAssemblyBean.AutoDetect.type.Panda" autowire="autodetect" />
        
    <bean id="kungfu" class="com.gp6.autoAssemblyBean.AutoDetect.type.KungFu" >
        <property name="name" value="Tai Ji" />
    </bean>

</beans>

package com.gp6.autoAssemblyBean.AutoDetect.type;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext(
                "com/gp6/autoAssemblyBean/AutoDetect/type/applicationContext.xml");

        Panda panda = (Panda) context.getBean("panda");
        System.out.println(panda);
    }
}