spring02

本部分是依赖注入。

1、环境（pojo）

**本部分摘抄自秦老师的笔记 **

• 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 。

本次联系所使用的类有：

• User

  package com.nevesettle.pojo;
  
  import java.util.*;
  
  public class Student {
      private String name;
      private Address address;
      private String[] books;
      private List<String> hobbys;
      private Map<String,String> card;
      private Set<String> game;
      private Properties info;
      private String wife;
  
      @Override
      public String toString() {
          return "Student{" +
                  "name='" + name + '\'' +
                  ", address=" + address.toString() +
                  ", books=" + Arrays.toString(books) +
                  ", hobbys=" + hobbys +
                  ", card=" + card +
                  ", game=" + game +
                  ", info=" + info +
                  ", wife='" + wife + '\'' +
                  '}';
      }
  
      public String getName() {
          return name;
      }
  
      public void setName(String name) {
          this.name = name;
      }
  
      public Address getAddress() {
          return address;
      }
  
      public void setAddress(Address address) {
          this.address = address;
      }
  
      public String[] getBooks() {
          return books;
      }
  
      public void setBooks(String[] books) {
          this.books = books;
      }
  
      public List<String> getHobbys() {
          return hobbys;
      }
  
      public void setHobbys(List<String> hobbys) {
          this.hobbys = hobbys;
      }
  
      public Map<String, String> getCard() {
          return card;
      }
  
      public void setCard(Map<String, String> card) {
          this.card = card;
      }
  
      public Set<String> getGame() {
          return game;
      }
  
      public void setGame(Set<String> game) {
          this.game = game;
      }
  
      public Properties getInfo() {
          return info;
      }
  
      public void setInfo(Properties info) {
          this.info = info;
      }
  
      public String getWife() {
          return wife;
      }
  
      public void setWife(String wife) {
          this.wife = wife;
      }
  }
  
  

• Address

  package com.nevesettle.pojo;
  
  public class Address {
      private String address;
  
      public String getAddress() {
          return address;
      }
  
      public void setAddress(String address) {
          this.address = address;
      }
  
      @Override
      public String toString() {
          return "Address{" +
                  "address='" + address + '\'' +
                  '}';
      }
  }
  

2、注入

注入的主要操作还是在xml中完成的。

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="address" class="com.nevesettle.pojo.Address">
        <property name="address" value="河北"/>
    </bean>

    <bean id="student" class="com.nevesettle.pojo.Student">
        <!--普通注入-->
        <property name="name" value="不将就"/>

        <!--bean注入-->
        <property name="address" ref="address"/>

        <!--数组注入-->
        <property name="books">
            <array>
                <value>三国演义</value>
                <value>水浒传</value>
                <value>西游记</value>
                <value>红楼梦</value>
            </array>
        </property>

        <!--list注入-->
        <property name="hobbys">
            <list>
                <value>听歌</value>
                <value>敲代码</value>
            </list>
        </property>

        <!--map注入-->
        <property name="card">
            <map>
                <entry key="身份证" value="130494111111111111"/>
                <entry key="银行卡" value="13115165165165165"/>
            </map>
        </property>

        <!--set注入 -->
        <property name="game">
            <set>
                <value>LOL</value>
            </set>
        </property>

        <!--properties注入-->
        <property name="info">
            <props>
                <prop key="学号">20201515</prop>
                <prop key="性别">男</prop>
            </props>
        </property>

        <!--null注入-->
        <property name="wife">
            <null/>
        </property>

    </bean>

</beans>