Spring中使用byType实现Beans自动装配

以下内容引用自http://wiki.jikexueyuan.com/project/spring/beans-auto-wiring/spring-autowiring-byType.html：

此模式通过属性类型来指定自动装配。Spring容器查看XML配置文件中将autowire属性设置为byType的bean。然后，如果它的类型与配置文件中的一个bean名称匹配，它将尝试匹配和连接一个属性。如果找到匹配项，它将注入这些bean。否则，bean将不会被连线。

例如，如果在配置文件中将bean定义设置为autowire="byType"，并且它包含spellChecker类型的spellChecker属性，则Spring会查找名为spellChecker的bean定义，并使用它来设置该属性。当然，还可以使用<property>标签连接剩余的属性。

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>testautowiringbytype</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>testautowiringbytype</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.testautowiringbytype;

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.testautowiringbytype;

public class TextEditor {
    private SpellChecker spellChecker;
    private String name;
    
    public void setSpellChecker(SpellChecker spellChecker){
        System.out.println("TextEditor通过setter初始化");
        this.spellChecker = spellChecker;
    }
    
    public void spellCheck() {
        this.spellChecker.checkSpelling();
    }
    
    public void setName(String name){
        this.name = name;
    }
    
    public void getName(){
        System.out.println(this.name);
    }
    
}

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
                        http://www.springframework.org/schema/beans/spring-beans.xsd">
    
    <bean id="spellChecker" class="com.jsoft.testspring.testautowiringbytype.SpellChecker"></bean>
    
    <bean id="textEditor" class="com.jsoft.testspring.testautowiringbytype.TextEditor" autowire="byType">
        <property name="Name" value="Hello World!"></property>
    </bean>
   
</beans>

修改之前的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
                        http://www.springframework.org/schema/beans/spring-beans.xsd">
    
    <bean id="spellChecker" class="com.jsoft.testspring.testautowiringbytype.SpellChecker"></bean>
    
    <bean id="textEditor" class="com.jsoft.testspring.testautowiringbytype.TextEditor">
        <property name="SpellChecker" ref="spellChecker"></property>
        <property name="Name" value="Hello World!"></property>
    </bean>
   
</beans>

运行结果：

测试工程：https://github.com/easonjim/5_java_example/tree/master/springtest/test11/testautowiringbytype