❤️Spring注入集合❤️（建议收藏）

柔情只为你懂 2023-10-03 15:49 33阅读 0赞

## ❤️Spring注入集合 ##

.以下是一些Spring常用的注入集合，请“食用”，记得给个三连噢！

如果需要传递类似于 Java Collection 类型的值，例如 List、Set、Map 和 properties，可以使用 Spring 提供的集合配置标签，如下表所示。

<table> 
 <thead> 
  <tr> 
   <th>标签</th> 
   <th>说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>list</td> 
   <td>用于注入 list 类型的值，允许重复</td> 
  </tr> 
  <tr> 
   <td>set</td> 
   <td>用于注入 set 类型的值，不允许重复</td> 
  </tr> 
  <tr> 
   <td>map</td> 
   <td>用于注入 key-value 的集合，其中 key-value 可以是任意类型</td> 
  </tr> 
  <tr> 
   <td>props</td> 
   <td>用于注入 key-value 的集合，其中 key-value 都是字符串类型</td> 
  </tr> 
 </tbody> 
</table>

String name;
    Address address;
    String[] books;
    List<String> hobbys;
    Map<String,String> card;
    Set<String> games;
    String wife;
    Properties info;

### ❤️示例 ###

下面使用 IDEA 演示如何注入集合，步骤如下：

1.  创建 SpringDemo 项目，并在 src 目录下创建包。
2.  添加相应的 jar 包，可以参考《[第一个Spring程序][Spring]》一节。
3.  在所包下创建 Address、Student 类。
4.  在 src 目录下创建 Spring 配置文件 beans.xml。
5.  运行 SpringDemo 项目。

### ❤️源码 ###

#### ❤️1、实体类 ####

**address类**

package com.kk.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 + '\'' +
                    '}';
        }
    }

**Student类**

package com.kk.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> games;
        private String wife;
        private Properties info;
    
        public Student() {
        
    
        }
    
        public Student(String name, Address address, String[] books,
                       List<String> hobbys, Map<String, String> card,
                       Set<String> games, String wife, Properties info) {
        
            this.name = name;
            this.address = address;
            this.books = books;
            this.hobbys = hobbys;
            this.card = card;
            this.games = games;
            this.wife = wife;
            this.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;
        }
    
        @Override
        public String toString() {
        
            return "Student{" +
                    "name='" + name + '\'' +
                    ", address=" + address.toString() +
                    ", books=" + Arrays.toString(books) +
                    ", hobbys=" + hobbys +
                    ", card=" + card +
                    ", games=" + games +
                    ", wife='" + wife + '\'' +
                    ", info=" + info +
                    '}';
        }
    }

#### ❤️ 2、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-3.0.xsd">
        <bean id="address" class="com.kk.pojo.Address">
            <property name="address" value="广东"></property>
        </bean>
    
    
        <bean id="student" class="com.kk.pojo.Student">
            
            <property name="name" value="火神"></property>
    
            <property name="address" ref="address"></property>
    
            <property name="books">
                <array>
                    <value>红楼梦</value>
                    <value>西游记</value>
                    <value>三国演义</value>
                    <value>水浒传</value>
                </array>
            </property>
    
    
            <property name="hobbys">
                <list>
                    <value>编程</value>
                    <value>听歌</value>
                    <value>吃</value>
                </list>
            </property>
    
    
            <property name="card">
                <map>
                    <entry key="身份证" value="4412002121223***"></entry>
                    <entry key="银行卡" value="654645454546"></entry>
                </map>
            </property>
    
    
            <property name="games">
                <set>
                    <value>LOL</value>
                    <value>CSOL</value>
                </set>
            </property>
    
    
            <property name="wife">
                <null></null>
            </property>
    
    
            <property name="info">
                <props>
                    <prop key="学号">2011***</prop>
                    <prop key="性别">男</prop>
                    <prop key="姓名">k</prop>
                    <prop key="password">123456</prop>
                </props>
            </property>
         </bean>
    
    </beans>

#### ❤️3、测试类 ####

import com.kk.pojo.Student;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    public class MyTest {
        
        public static void main(String[] args) {
        
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
            Student student =(Student) context.getBean("student");
            System.out.println(student.toString());
        }
    }

#### ❤️其他方式注入 ####

实体类：

package com.kk.pojo;
    
    public class User {
        
        private int age;
        private String name;
    
        //c命名空间需要有参构造器
    
    
        public User(int age, String name) {
        
            this.age = age;
            this.name = name;
        }
    
        public User() {
        
    
        }
    
        public int getAge() {
        
            return age;
        }
    
        public void setAge(int age) {
        
            this.age = age;
        }
    
        public String getName() {
        
            return name;
        }
    
        public void setName(String name) {
        
            this.name = name;
        }
    
        @Override
        public String toString() {
        
            return "User{" +
                    "age=" + age +
                    ", name='" + name + '\'' +
                    '}';
        }
    }

1、P命名空间注入 : 需要在头文件中加入约束文件

导入约束 : xmlns:p="http://www.springframework.org/schema/p"
    
     
     <bean id="user" class="com.kuang.pojo.User" p:name="kk" p:age="17"/>

测试类：

@Test
        public void test2(){
        
           ApplicationContext context = new ClassPathXmlApplicationContext("userbeans.xml");
    //        User user =(User) context.getBean("user");
            User user = context.getBean("user", User.class);
            System.out.println(user);
    
        }

2、c 命名空间注入 : 需要在头文件中加入约束文件

导入约束 : xmlns:c="http://www.springframework.org/schema/c"
     
     <bean id="user" class="com.kuang.pojo.User" c:name="kk" c:age="17"/>

测试类：

[Spring]: http://c.biancheng.net/spring/first-spring.html