理论

注入Bean：可以通过构造方法注入Bean，通过Set方法注入Bean；

集合类型有：List、Set、Map、Properties；

以及特殊的null值的注入；

通过构造方法注入Bean

<bean id="bean" class="com...Bean"><constructor-arg index="0" name="anotherBean" type="com...AnotherBean" ref="anotherBean /><constructor-arg index="1" name="stringValue" type="java.lang.String" value="stringValue1" />
</bean>

通过set方法注入Bean

<bean id="bean" class="com...Bean"><property name="anotherBean" ref="anotherBean" /><property name="string" value="setValue1"/>
</bean>

集合类型Bean注入

<bean id="bean" class="com...Bean"><property name="litOrSet"><list>     <!-- <set> --><value>aaaa</value><value>bbbb</value></list>    <!-- </set> --></property>
</bean>

<bean id="bean" class="com...Bean"><property name="mapOrProp"><map>    <!-- <props> --><entry key="aaa" value="111" /><prop key="aaa">111</prop></map>    <!-- </props> --></property>
</bean>

注入null值

<bean id="bean" class="com..Bean"><property name="nullValue"><null/></property>
</bean>

代码及演示

程序运行截图如下：

下面给出txt文本：

bean = Bean{anotherBean=injectbean.demo.AnotherBean@5c84624f, string='通过构造方法注入Bean', anotherBean1=injectbean.demo.AnotherBean@5c84624f, string1='通过set方法注入Bean', stringList=[第一个List值, 第二个List值, 第三个List值], anotherBeanList=[injectbean.demo.AnotherBean@5c84624f, injectbean.demo.AnotherBean@5c84624f], stringMap={key1=value1, key2=value2}, anotherBeanMap={injectbean.demo.AnotherBean@5c84624f=injectbean.demo.AnotherBean@5c84624f}, stringSet=[第一个Set值, 第二个Set值, 第三个Set值], anotherBeanSet=[injectbean.demo.AnotherBean@5c84624f], properties={heheda=dadada}}
---------华丽的分割线---------
bean.getStringList() = [第一个List值, 第二个List值, 第三个List值]
bean.getStringSet() = [第一个Set值, 第二个Set值, 第三个Set值]
bean.getStringMap() = {key1=value1, key2=value2}
bean.getAnotherBeanList() = [injectbean.demo.AnotherBean@5c84624f, injectbean.demo.AnotherBean@5c84624f]
bean.getAnotherBeanSet() = [injectbean.demo.AnotherBean@5c84624f]
bean.getAnotherBeanMap() = {injectbean.demo.AnotherBean@5c84624f=injectbean.demo.AnotherBean@5c84624f}
bean.getProperties() = {heheda=dadada}
bean.getAnotherBean2() = null

程序结构如下：

源码如下：

AnotherBean.java

package injectbean.demo;public class AnotherBean {}

Bean.java

package injectbean.demo;import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;public class Bean {@Overridepublic String toString() {return "Bean{" +"anotherBean=" + anotherBean +", string='" + string + '\'' +", anotherBean1=" + anotherBean1 +", string1='" + string1 + '\'' +", stringList=" + stringList +", anotherBeanList=" + anotherBeanList +", stringMap=" + stringMap +", anotherBeanMap=" + anotherBeanMap +", stringSet=" + stringSet +", anotherBeanSet=" + anotherBeanSet +", properties=" + properties +'}';}//通过构造方法注入Beanprivate AnotherBean anotherBean;private String string;public Bean(AnotherBean anotherBean, String string) {this.anotherBean = anotherBean;this.string = string;}public AnotherBean getAnotherBean() {return anotherBean;}public void setAnotherBean(AnotherBean anotherBean) {this.anotherBean = anotherBean;}public String getString() {return string;}public void setString(String string) {this.string = string;}//通过set方法注入Beanprivate AnotherBean anotherBean1;private String string1;public AnotherBean getAnotherBean1() {return anotherBean1;}public void setAnotherBean1(AnotherBean anotherBean1) {this.anotherBean1 = anotherBean1;}public String getString1() {return string1;}public void setString1(String string1) {this.string1 = string1;}//集合类型Bean的注入private List<String> stringList;private List<AnotherBean> anotherBeanList;private Map<String, String> stringMap;private Map<AnotherBean, AnotherBean> anotherBeanMap;private Set<String> stringSet;private Set<AnotherBean> anotherBeanSet;private Properties properties;public List<String> getStringList() {return stringList;}public void setStringList(List<String> stringList) {this.stringList = stringList;}public List<AnotherBean> getAnotherBeanList() {return anotherBeanList;}public void setAnotherBeanList(List<AnotherBean> anotherBeanList) {this.anotherBeanList = anotherBeanList;}public Map<String, String> getStringMap() {return stringMap;}public void setStringMap(Map<String, String> stringMap) {this.stringMap = stringMap;}public Map<AnotherBean, AnotherBean> getAnotherBeanMap() {return anotherBeanMap;}public void setAnotherBeanMap(Map<AnotherBean, AnotherBean> anotherBeanMap) {this.anotherBeanMap = anotherBeanMap;}public Set<String> getStringSet() {return stringSet;}public void setStringSet(Set<String> stringSet) {this.stringSet = stringSet;}public Set<AnotherBean> getAnotherBeanSet() {return anotherBeanSet;}public void setAnotherBeanSet(Set<AnotherBean> anotherBeanSet) {this.anotherBeanSet = anotherBeanSet;}public Properties getProperties() {return properties;}public void setProperties(Properties properties) {this.properties = properties;}//null值注入private AnotherBean anotherBean2;public AnotherBean getAnotherBean2() {return anotherBean2;}public void setAnotherBean2(AnotherBean anotherBean2) {this.anotherBean2 = anotherBean2;}
}

spring.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-2.5.xsd"><bean class="injectbean.demo.AnotherBean" id="anotherBean" /><bean class="injectbean.demo.Bean" id="bean"><constructor-arg index="0" type="injectbean.demo.AnotherBean" ref="anotherBean"/><constructor-arg index="1" type="java.lang.String" value="通过构造方法注入Bean" /><property name="anotherBean1" ref="anotherBean" /><property name="string1" value="通过set方法注入Bean" /><property name="stringList"><list><value>第一个List值</value><value>第二个List值</value><value>第三个List值</value></list></property><property name="anotherBeanList"><list><ref bean="anotherBean" /><ref bean="anotherBean" /></list></property><property name="stringSet"><set><value>第一个Set值</value><value>第二个Set值</value><value>第三个Set值</value></set></property><property name="anotherBeanSet"><set><ref bean="anotherBean" /><ref bean="anotherBean" /></set></property><property name="stringMap"><map><entry key="key1" value="value1" /><entry key="key2" value="value2" /></map></property><property name="anotherBeanMap"><map><entry key-ref="anotherBean" value-ref="anotherBean" /></map></property><property name="properties"><props><prop key="heheda">dadada</prop></props></property><property name="anotherBean2"><null/></property></bean>
</beans>

DemoApplicationTests.java

package injectbean.demo;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.boot.test.context.SpringBootTest;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import org.springframework.test.context.junit4.SpringRunner;@RunWith(SpringRunner.class)
@SpringBootTest
public class DemoApplicationTests {@Testpublic void contextLoads() {ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");Bean bean = context.getBean("bean", Bean.class);System.out.println("bean = " + bean);System.out.println("---------华丽的分割线---------");System.out.println("bean.getStringList() = " + bean.getStringList());System.out.println("bean.getStringSet() = " + bean.getStringSet());System.out.println("bean.getStringMap() = " + bean.getStringMap());System.out.println("bean.getAnotherBeanList() = " + bean.getAnotherBeanList());System.out.println("bean.getAnotherBeanSet() = " + bean.getAnotherBeanSet());System.out.println("bean.getAnotherBeanMap() = " + bean.getAnotherBeanMap());System.out.println("bean.getProperties() = " + bean.getProperties());System.out.println("bean.getAnotherBean2() = " + bean.getAnotherBean2());}}

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理论

代码及演示

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