Spring的依赖注入

Spring IOC 依赖注入

• 依赖：bean对象的创建依赖于容器

• 注入：bean对象中的所有属性，由容器来注入

  实体类：

  package com.xia.pojo;
  
  import lombok.Data;
  
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  import java.util.Set;
  
  @Data
  public class Student {
      private  String type;
      private String name;
      private Address address;
      private  String[] books;
      private List<String> hobby;
      private Map<String,String> card;
      private Set<String> game;
      private String wife;
      private Properties info;
  
      public Student(String type) {
          this.type = type;
      }
  }
  
  

  总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">
  
      <import resource="Bean.xml"></import>
  
  </beans>
  

  Bean.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="address" class="com.xia.pojo.Address">
      <property name="address" value="山东"></property>
  </bean>
      <bean id="student" class="com.xia.pojo.Student">
  <!--        构造方法注入-->
          <constructor-arg index="0" value="Sping"></constructor-arg>
  <!--        1.普通值注入，使用value-->
          <property name="name" value="夏小皮"></property>
  <!--        2.Bean注入-->
          <property name="address" ref="address"></property>
  <!--        3.数组注入-->
          <property name="books">
              <array>
                  <value>红楼梦</value>
                  <value>西游记</value>
                  <value>三国演义</value>
              </array>
          </property>
  <!--        4.List注入-->
          <property name="hobby">
              <list>
                  <value>听歌</value>
                  <value>代码</value>
                  <value>电影</value>
              </list>
          </property>
  <!--        5.map注入-->
          <property name="card">
              <map>
                  <entry key="银行卡" value="454545"></entry>
                  <entry key="身份证"  value="454545454787"></entry>
              </map>
          </property>
  <!--        6.set注入-->
          <property name="game">
              <set>
                  <value>LOL</value>
              </set>
          </property>
  <!--      7.空值注入  -->
          <property name="info">
              <null></null>
          </property>
      </bean>
  
  
  </beans>