Spring注入内部的Beans

以下内容引用自http://wiki.jikexueyuan.com/project/spring/injecting-inner-beans.html：

如你所知，Java内部类在其他类的范围内定义，类似地，内部bean是在另一个bean的范围内定义的bean。因此，<property />或<constructor-arg />元素中的<bean />元素称为内部bean，如下所示：

<?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-3.0.xsd">

   <bean id = "outerBean" class = "...">

      <property name = "target">

         <bean id = "innerBean" class = "..."/>

      </property>

   </bean>

</beans>

写法和Java内部类相似。

例子：

pom.xml：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  <modelVersion>4.0.0</modelVersion>

  <groupId>com.jsoft.testspring</groupId>

  <artifactId>testinnerbean</artifactId>

  <version>0.0.1-SNAPSHOT</version>

  <packaging>jar</packaging>

  <name>testinnerbean</name>

  <url>http://maven.apache.org</url>

  <properties>

    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

  </properties>

  <dependencies>

    <dependency>

      <groupId>junit</groupId>

      <artifactId>junit</artifactId>

      <version>3.8.1</version>

      <scope>test</scope>

    </dependency>

    <!-- Spring Core -->

    <!-- http://mvnrepository.com/artifact/org.springframework/spring-core -->

    <dependency>

        <groupId>org.springframework</groupId>

        <artifactId>spring-core</artifactId>

        <version>4.1.4.RELEASE</version>

    </dependency>

    <!-- Spring Context -->

    <!-- http://mvnrepository.com/artifact/org.springframework/spring-context -->

    <dependency>

        <groupId>org.springframework</groupId>

        <artifactId>spring-context</artifactId>

        <version>4.1.4.RELEASE</version>

    </dependency>

  </dependencies>

</project>

SpellChecker.java：

package com.jsoft.testspring.testinnerbean;

public class SpellChecker {

    public SpellChecker(){

        System.out.println("SpellChecker无参数构造函数初始化");

    }

    public void checkSpelling(){

        System.out.println("SpellChecker检查方法");

    }

}

TextEditor.java：

package com.jsoft.testspring.testinnerbean;

public class TextEditor {

    private SpellChecker spellChecker;

    public void setSpellChecker(SpellChecker spellChecker){

        System.out.println("TextEditor通过setter初始化");

        this.spellChecker = spellChecker;

    }

    public void spellCheck() {

        this.spellChecker.checkSpelling();

    }

}

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"

    xmlns:p="http://www.springframework.org/schema/p"

    xsi:schemaLocation="http://www.springframework.org/schema/beans

                        http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="textEditor" class="com.jsoft.testspring.testinnerbean.TextEditor">

        <property name="SpellChecker">

            <bean id="spellCheckerId" class="com.jsoft.testspring.testinnerbean.SpellChecker"></bean>

        </property>

    </bean>

</beans>

App.java：

package com.jsoft.testspring.testinnerbean;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

/**

 * Hello world!

 *

 */

public class App

{

    public static void main( String[] args )

    {

        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");

        TextEditor textEditor = (TextEditor)applicationContext.getBean("textEditor");

        textEditor.spellCheck();

    }

}

运行结果：

测试工程：https://github.com/easonjim/5_java_example/tree/master/springtest/test9/testinnerbean

巴特西

Spring注入内部的Beans

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