Spring+Maven学习实验- Spring 中将值注入集合类型（三）

Z时代
2024-01-10
分类：综合

本文内容纲要：Spring+Maven学习实验- Spring 中将值注入集合类型（三）

将值注入集合类型，包含以下四种主要的集合类型：

List ——

Set ——

Map ——

Properties ——

1.pom.xml

略

2.编写 Person.java && Customer.java

package com.shiyanlou.spring.collections;
public class Person {
    private String name;
    private String address;
    private int age;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    @Override
    public String toString() {
        return "Person [name=" + name + ", address=" + address + ", age=" + age + "]";
    }
}
package com.shiyanlou.spring.collections;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
public class Customer {
    private List<Object> lists;//这里的lists要和Bean中的property标签的name一样
    private Set<Object> sets;
    private Map<Object,Object> maps;
    private Properties pros;
    public List<Object> getLists() {
        return lists;
    }
    public void setLists(List<Object> lists) {
        this.lists = lists;
    }
    public Set<Object> getSets() {
        return sets;
    }
    public void setSets(Set<Object> sets) {
        this.sets = sets;
    }
    public Map<Object, Object> getMaps() {
        return maps;
    }
    public void setMaps(Map<Object, Object> maps) {
        this.maps = maps;
    }
    public Properties getPros() {
        return pros;
    }
    public void setPros(Properties pros) {
        this.pros = pros;
    }
    private Person person;//不要忘记写内部要引用的Bean
    public Customer(Person person){
        this.person = person;
    }
    public Customer(){}
    public Person getPerson() {
        return person;
    }
    public void setPerson(Person person) {
        this.person = person;
    }
    @Override
    public String toString() {
        return "Customer [person=" + person + "]";
    }
}

注意： JavaBean 关于属性命名的特殊规范，spring 配置文件中元素所指定的属性名和 Bean 实现类的 Setter 方法满足 Sun JavaBean 的属性命名规范: xxx 的属性对应 setXxx() 方法。一般情况下 Java 的属性变量名都以小写字母起头，如: maxSpeed 。但也存在特殊的情况，考虑到一些特定意义的大写英文缩略词(如: USA 、 XML )，JavaBean 也允许大写字母起头的属性变量名，不过必须满足: 变量的前两个字母要么全部大写，要么全部小写.如: iC 、 iCcard 、 iDcode 这些都不合法的。

3.编写 SpringCollections.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="customerBean" class="com.shiyanlou.spring.collections.Customer">
      <!-- java.util.List -->
      <property name="lists">
        <list>
          <value>1</value> <!-- List 属性既可以通过 <value> 注入字符串，也可以通过 <ref> 注入容器中其他的 Bean-->
          <ref bean="personBean"/>
          <value>2</value>
          <bean class="com.shiyanlou.spring.collections.Person">
             <property name="name" value="testList"/>
             <property name="address" value="Wuhan"/>
             <property name="age" value="18"/>
          </bean>
        </list>
      </property>
      <!-- java.util.Set -->
      <property name="sets">
        <set>
          <value>1</value>
          <ref bean="personBean"/>
          <bean class="com.shiyanlou.spring.collections.Person">
             <property name="name" value="testSet"/>
             <property name="address" value="Wuhan"/>
             <property name="age" value="18"/>
          </bean>
        </set>
      </property>
      <!-- java.util.Map -->
      <property name="maps">
        <map>
          <entry key="Key 1" value="1"/> <!--一个 entry 就是一个 Map 元素-->
          <entry key="Key 2" value-ref="personBean"/>
          <entry key="key 3">
            <bean class="com.shiyanlou.spring.collections.Person">
               <property name="name" value="testMap"/>
               <property name="address" value="Wuhan"/>
               <property name="age" value="18"/>
            </bean>
          </entry>
        </map>
      </property>
      <property name="pros">
         <props>
            <prop key="admin">admin@nospam.com</prop>
            <prop key="support">support@nospam.com</prop>
         </props>
      </property>    
    </bean>
    <bean id="personBean" class="com.shiyanlou.spring.collections.Person">
        <property name="name" value="shiyanlouPersonBean" />
        <property name="address" value="chengdu" />
        <property name="age" value="25" />
    </bean>
</beans>

4.编写测试类App.java

package com.shiyanlou.spring.collections;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App {
	private static ApplicationContext context;
	public static void main(String[] args) {
		context = new ClassPathXmlApplicationContext("SpringCollections.xml");
		/*
		 * 1.List的情况
		 */
//		Customer lists = (Customer)context.getBean("customerBean");
//		System.out.println(lists.getLists().toString());
		/*
		 * 2.Set的情况
		 */
//		 Customer sets = (Customer) context.getBean("customerBean");
//       System.out.println(sets.getSets().toString());
         /*
          * 3.Map的情况
          */
//         Customer maps = (Customer) context.getBean("customerBean");
//         System.out.println(maps.getMaps().toString());
         /*
          * 4.Property
          */
         Customer pros = (Customer) context.getBean("customerBean");
         System.out.println(pros.getPros().toString());
	}
}