【Spring5】Spring5基础教程(3)

前言：

本文内容：Spring配置说明、DI依赖注入环境、依赖注入的Set注入

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Spring配置说明

别名

别名alias

<!--    别名 alias-->
    <alias name="user" alias="users"/>

Bean的配置

<!--    bean的配置
        id: bean 的唯一标识符 也就相当于我们学的对象名
        class：bean 对象所对应的类型
        name: 也是别名 而且name可以取多个别名
-->
<bean id="userT" class="com.jokerdig.pojo.User" name="userT2,userNew2">
    <property name="name" value="Joker大雄"/>
</bean>

Import

import一般用于团队开发，它可以将多个配置文件，导入合并为一个

在resources创建applicationContext.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">

    <!--可以通过import引入多个配置文件合并为一个，一般适用于团队开发-->
    <import resource="beans.xml"/>
</beans>

DI依赖注入环境

构造器注入

无参构造和有参构造，上一篇已经讲过

<!--    这里本质使用实体类的无参构造 默认-->
<bean name="user" class="com.jokerdig.pojo.User">
    <property name="name" value="Joker大雄"/>
</bean>

Set方式注入(重点)

• 依赖注入：Set注入
  • 依赖：bean对象创建依赖于容器
  • 注入：bean对象中的所有属性，由容器来注入

测试环境搭建

1. 复杂类型

   Map,Set,List,实体类,Properties.....

2. 创建测试对象

   新建一个Maven项目模块

   创建Student和Address实体类

   Student.java

   package com.jokerdig.pojo;
   
   import java.util.*;
   
   /**
    * @author Joker大雄
    * @data 2022/5/12 - 19:28
    **/
   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 Properties info;
       private String not;
   
       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 Properties getInfo() {
           return info;
       }
   
       public void setInfo(Properties info) {
           this.info = info;
       }
   
       public String getNot() {
           return not;
       }
   
       public void setNot(String not) {
           this.not = not;
       }
   
       @Override
       public String toString() {
           return "Student{" +
                   "name='" + name + '\'' +
                   ", address=" + address.toString() +
                   ", books=" + Arrays.toString(books) +
                   ", hobbys=" + hobbys +
                   ", card=" + card +
                   ", games=" + games +
                   ", info=" + info +
                   ", not='" + not + '\'' +
                   '}';
       }
   }

   Address.java

   package com.jokerdig.pojo;
   
   /**
    * @author Joker大雄
    * @data 2022/5/12 - 19:28
    **/
   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 + '\'' +
                   '}';
       }
   }

3. 创建beans.xml文件

   <?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="student" class="com.jokerdig.pojo.Student">
   <!--        第一种 普通注入 value-->
           <property name="name" value="张三"/>
       </bean>
   </beans>

4. 简单测试环境搭建

   package com.jokerdig.test;
   
   import com.jokerdig.pojo.Student;
   import org.junit.Test;
   import org.springframework.context.ApplicationContext;
   import org.springframework.context.support.ClassPathXmlApplicationContext;
   
   /**
    * @author Joker大雄
    * @data 2022/5/12 - 19:36
    **/
   public class SpringTest {
       @Test
       public void test(){
           ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
           Student student = (Student) context.getBean("student");
   
           System.out.println(student.getName());
       }
   }

   运行结果

   张三
   
   Process finished with exit code 0

依赖注入的Set注入

beans.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">

<!--    引入address-->
    <bean id="address" class="com.jokerdig.pojo.Address">
        <property name="address" value="陕西西安"/>
    </bean>

    <bean id="student" class="com.jokerdig.pojo.Student">
<!--        第一种 普通注入 value-->
        <property name="name" value="张三"/>
<!--        第二种 Bean注入 ref -->
        <property name="address" ref="address"/>
<!--        数组注入 property ->array -> value -->
        <property name="books">
            <array>
                <value>三国</value>
                <value>红楼梦</value>
                <value>福尔摩斯</value>
                <value>西游记</value>
                <value>狂人日记</value>
            </array>
        </property>
<!--        List-->
        <property name="hobbys">
            <list>
                <value>听歌</value>
                <value>看电影</value>
                <value>打游戏</value>
                <value>打篮球</value>
                <value>跑步</value>
            </list>
        </property>
<!--        map-->
        <property name="card">
            <map>
                <entry key="身份证" value="612729199901010001"/>
                <entry key="学号" value="20212B3321"/>
                <entry key="编号" value="033412"/>
            </map>
        </property>
<!--        set-->
        <property name="games">
            <set>
                <value>武士:零</value>
                <value>Muse Dash</value>
                <value>蔚蓝</value>
            </set>
        </property>
<!--        properties key=value-->
        <property name="info">
            <props>
                <prop key="序号">0001</prop>
                <prop key="性别">男</prop>
                <prop key="username">root</prop>
            </props>
        </property>
<!--        null-->
        <property name="not">
            <null/>
        </property>
    </bean>
</beans>

普通注入

<bean id="student" class="com.jokerdig.pojo.Student">
    <!--            第一种 普通注入 value-->
    <property name="name" value="张三"/>
    <!--.......-->
</bean>

Bean注入

<!--        第二种 Bean注入 ref -->
<property name="address" ref="address"/>

数组(Array)注入

<!--        数组注入 property ->array -> value -->
<property name="books">
    <array>
        <value>三国</value>
        <value>红楼梦</value>
        <value>福尔摩斯</value>
        <value>西游记</value>
        <value>狂人日记</value>
    </array>
</property>

数组(List)注入

<!--        List-->
<property name="hobbys">
    <list>
        <value>听歌</value>
        <value>看电影</value>
        <value>打游戏</value>
        <value>打篮球</value>
        <value>跑步</value>
    </list>
</property>

Map注入

<!--        map-->
<property name="card">
    <map>
        <entry key="身份证" value="612729199901010001"/>
        <entry key="学号" value="20212B3321"/>
        <entry key="编号" value="033412"/>
    </map>
</property>

Set注入

<!--        set-->
<property name="games">
    <set>
        <value>武士:零</value>
        <value>Muse Dash</value>
        <value>蔚蓝</value>
    </set>
</property>

Properties注入

<!--        properties key=value-->
<property name="info">
    <props>
        <prop key="序号">0001</prop>
        <prop key="性别">男</prop>
        <prop key="username">root</prop>
    </props>
</property>

NULL注入

<!--        null-->
<property name="not">
    <null/>
</property>

测试注入结果

package com.jokerdig.test;

import com.jokerdig.pojo.Student;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @author Joker大雄
 * @data 2022/5/12 - 19:36
 **/
public class SpringTest {
    @Test
    public void test(){
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        Student student = (Student) context.getBean("student");
        // 输入注入结果
        System.out.println(student.toString());
    }
}

运行结果

Student{
    name='张三', 
    address=Address{
        address='陕西西安'
    }, 
    books=[三国, 红楼梦, 福尔摩斯, 西游记, 狂人日记], 
    hobbys=[听歌, 看电影, 打游戏, 打篮球, 跑步], 
    card={
        身份证=612729199901010001, 
        学号=20212B3321, 
        编号=033412
    }, 
    games=[武士:零, Muse Dash, 蔚蓝], 
    info={
        序号=0001, 
        性别=男, 
        username=root
    }, 
    not='null'
}

Process finished with exit code 0