5、依赖注入

AnJiaYu / 2023-08-27 / 原文

5、依赖注入

5.1、构造器注入

前面已经说过了

5.2、set方法注入

 

  • 依赖注入:set 注入

    • 依赖:Bean对象的从创建依赖于容器

    • 注入:Bean所有对象的属性,由容器来注入

环境搭建:

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;

@Override
public String toString() {
return "Student{" +
"name='" + name + '\'' +
", address=" + address +
", books=" + Arrays.toString(books) +
", hobbys=" + hobbys +
", card=" + card +
", games=" + games +
", wife='" + wife + '\'' +
", info=" + info +
'}';
}

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> getGames() {
return games;
}

public void setGames(Set<String> games) {
this.games = games;
}

public String getWife() {
return wife;
}

public void setWife(String wife) {
this.wife = wife;
}

public Properties getInfo() {
return info;
}

public void setInfo(Properties info) {
this.info = info;
}
}
public class Address {
private String address;

public String getAddress() {
return address;
}

public void setAddress(String address) {
this.address = address;
}
}
  • 第一种注入方法:value值注入

  <bean id="student" class="com.an.pojo.Student" >
<!-- 第一种注入方式 value值进行注入-->
<property name="name" value="张三"></property>
</bean>
  • 第二种方式:Bean注入

    <!--            第二种注入方式 Bean注入-->
    <property name="address" ref="address"></property>
  • 数组注入

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

    <!--            list集合注入-->
    <property name="hobbys">
    <list>
    <value>唱歌</value>
    <value>跳舞</value>
    <value>篮球</value>
    </list>
    </property>

     

  • Map注入

    <!--            Map注入-->
    <property name="card" >
    <map>
    <entry key="身份证" value="111111111111111"></entry>
    <entry key="卡号" value="1231231231231231"></entry>
    </map>
    </property>
  • Set集合注入

    <!--            set集合注入-->
    <property name="games">
    <set>
    <value>LOL</value>
    <value>CF</value>
    </set>
    </property>
  • Properties注入

    <!--            Properties注入-->
    <property name="info">
    <props>
    <prop key="url">jdbc:mysql://localhost:3306</prop>
    <prop key="username">root</prop>
    <prop key="password">123456</prop>
    </props>
  •  

5.3、扩展方法注入

 

  • P命名空间注入 直接注入值

    引入P命名空间: xmlns:p="http://www.springframework.org/schema/p"

    <?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <beans>
    <bean id="user" class="com.an.pojo.User" p:name="张三" p:age="18"></bean>
    </beans>


    </beans>
  • C命名空间注入 通过构造器进行注入 需要有有参构造器

  • 引入C命名空间 xmlns:c="http://www.springframework.org/schema/c"

    <bean id="user2" class="com.an.pojo.User" c:name="李四" c:age="20"></bean>