Spring配置介紹

首先說說别名alias，以一個代碼的例子講解

首先是一個User實體類

package com.zhiying.pojo;

public class User {
    private String name;

    public String getName() {
        return name;
    }

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

    public void show() {
        System.out.println("name=" + name);
    }
}
      

然後是配置檔案

<?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="user" class="com.zhiying.pojo.User">
        <property name="name" value="賀志營"/>
    </bean>

<!--    添加了别名我們可以通過别名來擷取-->
    <alias name="user" alias="me"/>


</beans>      

最後是通過别名測試

import com.zhiying.pojo.User;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        User user = (User) context.getBean("me");
        user.show();
    }
}
      

運作結果：

可以擷取

bean的配置

把上面的配置檔案修改為如下

<?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的配置
    id：bean的唯一辨別符，也就是我們的對象名
    class：bean對象對應的全限類名，包名+類名
    name：也是别名
-->
    <bean id="user" class="com.zhiying.pojo.User" name="hehe">
        <property name="name" value="賀志營"/>
    </bean>


</beans>      

把測試類也修改了

import com.zhiying.pojo.User;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        User user = (User) context.getBean("hehe");
        user.show();
    }
}
      

這裡的name屬性值可以有多個，把配置檔案修改為下

<?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的配置
    id：bean的唯一辨別符，也就是我們的對象名
    class：bean對象對應的全限類名，包名+類名
    name：也是别名，可以同時取多個
-->
    <bean id="user" class="com.zhiying.pojo.User" name="hehe me,you;aa">
        <property name="name" value="賀志營"/>
    </bean>


</beans>      

測試類也修改了

import com.zhiying.pojo.User;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        User user = (User) context.getBean("hehe");
        User user1 = (User) context.getBean("me");
        User user2 = (User) context.getBean("aa");
        user.show();
        user1.show();
        user2.show();
    }
}
      

這裡的name别名，比上面那個alias強大。

import：可以将多個配置檔案導入合并為一個，修改配置檔案如下

<?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的配置
    id：bean的唯一辨別符，也就是我們的對象名
    class：bean對象對應的全限類名，包名+類名
    name：也是别名
-->
    <bean id="user" class="com.zhiying.pojo.User" name="hehe me,you">
        <property name="name" value="賀志營"/>
    </bean>


</beans>      

<?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="user" class="com.zhiying.pojo.User" name="aa">
        <property name="name" value="賀志營"/>
    </bean>
</beans>      

<?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">

    <import resource="Beans.xml"/>
    <import resource="beans1.xml"/>
</beans>      

import com.zhiying.pojo.User;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        User user = (User) context.getBean("hehe");
        User user1 = (User) context.getBean("me");
        User user2 = (User) context.getBean("aa");
        user.show();
        user1.show();
        user2.show();
    }
}