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/beanshttp://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/beanshttp://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
