Bean的配置
<!--bean就是java对象,由Spring创建和管理--> <!-- id 是bean的标识符,要唯一,如果没有配置id,name就是默认标识符 如果配置id,又配置了name,那么name是别名 name可以设置多个别名,可以用逗号,分号,空格隔开 如果不配置id和name,可以根据applicationContext.getBean(.class)获取对象; class是bean的全限定名=包名+类名 --> <bean> <property value="Spring"/> </bean>import
团队的合作通过import来实现 .
<import resource="{path}/beans.xml"/> 3、依赖注入（DI）概念
依赖注入（Dependency Injection,DI）。
依赖 : 指Bean对象的创建依赖于容器 . Bean对象的依赖资源 .
注入 : 指Bean对象所依赖的资源 , 由容器来设置和装配 .
Set 注入 （重点）
要求被注入的属性 , 必须有set方法 , set方法的方法名由set + 属性首字母大写 , 如果属性是boolean类型 , 没有set方法 , 是 is .
测试pojo类 :
Address.java
public class Address { private String address; public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } }Student.java
package com.kuang.pojo; import java.util.List; import java.util.Map; import java.util.Properties; import java.util.Set; public class Student { private String name; private Address address; private String[] books; private List<String> hobbys; private Map<String,String> card; private Set<String> games; private String wife; private Properties info; public void setName(String name) { this.name = name; } public void setAddress(Address address) { this.address = address; } public void setBooks(String[] books) { this.books = books; } public void setHobbys(List<String> hobbys) { this.hobbys = hobbys; } public void setCard(Map<String, String> card) { this.card = card; } public void setGames(Set<String> games) { this.games = games; } public void setWife(String wife) { this.wife = wife; } public void setInfo(Properties info) { this.info = info; } public void show(){ System.out.println("name="+ name + ",address="+ address.getAddress() + ",books=" ); for (String book:books){ System.out.print("<<"+book+">>\t"); } System.out.println("\n爱好:"+hobbys); System.out.println("card:"+card); System.out.println("games:"+games); System.out.println("wife:"+wife); System.out.println("info:"+info); } } 3.1、常量注入 <bean> <property value="小明"/> </bean>测试：
@Test public void test01(){ ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); Student student = (Student) context.getBean("student"); System.out.println(student.getName()); } 3.2、Bean注入注意点：这里的值是一个引用，ref
<bean> <property value="重庆"/> </bean> <bean> <property value="小明"/> <property ref="addr"/> </bean> 3.3、数组注入 <bean> <property value="小明"/> <property ref="addr"/> <property> <array> <value>西游记</value> <value>红楼梦</value> <value>水浒传</value> </array> </property> </bean> 3.4、List注入 <property> <list> <value>听歌</value> <value>看电影</value> <value>爬山</value> </list> </property> 3.5、Map注入 <property> <map> <entry key="中国邮政" value="456456456465456"/> <entry key="建设" value="1456682255511"/> </map> </property> 3.6、set注入 <property> <set> <value>LOL</value> <value>BOB</value> <value>COC</value> </set> </property> 3.7、Null注入 <property><null/></property> 3.8、Properties注入 <property> <props> <prop key="学号">20190604</prop> <prop key="性别">男</prop> <prop key="姓名">小明</prop> </props> </property>测试结果：