JavaWeb学习-Spring框架-6-Spring属性注入之复杂对象注入

绝地灬酷狼 2022-01-19 23:45 294阅读 0赞

前面我们介绍了四种注入方式，都是在介绍单个值得注入，没有遇到复杂对象，那个car对象不算。今天来看看如果属性是数组，列表，Map和Properties如何注入。

**1. 文件准备**

还是前面的injection包下新建一个CollectionBean类，里面有一个Demo1.java和一个配置文件

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**2.数组类型注入**

先来看看CollectionBean.java代码内容

package com.anthony.injection;
    
    import java.util.Arrays;
    import java.util.List;
    import java.util.Map;
    import java.util.Properties;
    
    public class CollectionBean {
    	
    	private Object[] arr; //数组类型注入
    	private List li; //List/set类型注入
    	private Map map; // Map类型注入
    	private Properties pro; //properties类型注入
    	
    	public Object[] getArr() {
    		return arr;
    	}
    	public void setArr(Object[] arr) {
    		this.arr = arr;
    	}
    	public List getLi() {
    		return li;
    	}
    	public void setLi(List li) {
    		this.li = li;
    	}
    	public Map getMap() {
    		return map;
    	}
    	public void setMap(Map map) {
    		this.map = map;
    	}
    	public Properties getPro() {
    		return pro;
    	}
    	public void setPro(Properties pro) {
    		this.pro = pro;
    	}
    	@Override
    	public String toString() {
    		return "CollectionBean [arr=" + Arrays.toString(arr) + ", li=" + li + ", map=" + map + ", pro=" + pro + "]";
    	}
    	
    	
    }

关于数组类型注入方式的配置文件内容

Demo1.java内容

package com.anthony.injection;
     
    import org.junit.Test;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
     
    public class Demo1 {
     
    	@Test
    	public void fun1() {
    		//1 创建容器对象
    		ApplicationContext ac = new ClassPathXmlApplicationContext("com/anthony/injection/applicationContext.xml");
    		//2 向容器 要 CollectionBean对象
    		CollectionBean c = (CollectionBean) ac.getBean("cb");
    		//3 打印CollectionBean对象
    		System.out.println(c); 
    	}
     
    }

运行结果

CollectionBean [arr=[tom], li=null, map=null, pro=null]

如果数组中需要插入多个值，配置文件这样写

<?xml version="1.0" encoding="UTF-8"?>
    
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    	   xmlns="http://www.springframework.org/schema/beans" 
    	   xsi:schemaLocation="http://www.springframework.org/schema/beans 
    	   http://www.springframework.org/schema/beans/spring-beans.xsd ">
    	
    	<bean name="user" class="com.anthony.bean.User">
    		<property name="name" value="tom"></property>
    		<property name="age" value="18"></property>
    	</bean>
    	
    	
    	<bean name="cb" class="com.anthony.injection.CollectionBean">
    		
    		
    		<property name="arr">
    			<array>
    				<value>tom</value>
    				<value>jerry</value>
    				<ref bean="user" />
    			</array>
    		</property>
    	</bean>
    </beans>

运行下Demo1.java，输出

CollectionBean [arr=[tom, jerry, User [name=tom, age=18]], li=null, map=null, pro=null]

这里用到了前面的配置的user这个bean对象。

**3.List类型注入**

同样，List也分一个值注入和多个值注入，先来看一个值的注入

<?xml version="1.0" encoding="UTF-8"?>
    
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    	   xmlns="http://www.springframework.org/schema/beans" 
    	   xsi:schemaLocation="http://www.springframework.org/schema/beans 
    	   http://www.springframework.org/schema/beans/spring-beans.xsd ">
    	
    	<bean name="user" class="com.anthony.bean.User">
    		<property name="name" value="tom"></property>
    		<property name="age" value="18"></property>
    	</bean>
    	
    	
    	<bean name="cb" class="com.anthony.injection.CollectionBean">
    		
    		<property name="li" value="Lucy"></property>
    		
    	</bean>
    </beans>

运行结果

CollectionBean [arr=null, li=[Lucy], map=null, pro=null]

再来看看多个值的注入

<?xml version="1.0" encoding="UTF-8"?>
    
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    	   xmlns="http://www.springframework.org/schema/beans" 
    	   xsi:schemaLocation="http://www.springframework.org/schema/beans 
    	   http://www.springframework.org/schema/beans/spring-beans.xsd ">
    	
    	<bean name="user" class="com.anthony.bean.User">
    		<property name="name" value="tom"></property>
    		<property name="age" value="18"></property>
    	</bean>
    	
    	
    	<bean name="cb" class="com.anthony.injection.CollectionBean">
    		
    		
    		<property name="li">
    			<list>
    				<value>tom</value>
    				<value>jerry</value>
    				<ref bean="user" />
    			</list>
    		</property>
    		
    	</bean>
    </beans>

运行结果

CollectionBean [arr=null, li=[tom, jerry, User [name=tom, age=18]], map=null, pro=null]

**4.Map类型注入**

Map中都是一些键值对，下面看看map对象注入方式

<?xml version="1.0" encoding="UTF-8"?>
    
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    	   xmlns="http://www.springframework.org/schema/beans" 
    	   xsi:schemaLocation="http://www.springframework.org/schema/beans 
    	   http://www.springframework.org/schema/beans/spring-beans.xsd ">
    	
    	<bean name="user" class="com.anthony.bean.User">
    		<property name="name" value="tom"></property>
    		<property name="age" value="18"></property>
    	</bean>
    	
    	
    	<bean name="cb" class="com.anthony.injection.CollectionBean">
    		
    		<property name="map">
    			<map>
    				<entry key="user" value="root"></entry>
    				<entry key="password" value="123456"></entry>
    				<entry key="url" value="jdbc:mysql://localhost:3306/j2ee"></entry>
    			</map>
    		</property>
    		
    	</bean>
    </beans>

这里模拟JDBC配置信息写一个map对象注入，运行结果如下

CollectionBean [arr=null, li=null, map={user=root, password=123456, url=jdbc:mysql://localhost:3306/j2ee}, pro=null]

来一个map中键值都是高级对象的情况

<?xml version="1.0" encoding="UTF-8"?>
    
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    	   xmlns="http://www.springframework.org/schema/beans" 
    	   xsi:schemaLocation="http://www.springframework.org/schema/beans 
    	   http://www.springframework.org/schema/beans/spring-beans.xsd ">
    	
    	<bean name="user" class="com.anthony.bean.User">
    		<property name="name" value="tom"></property>
    		<property name="age" value="18"></property>
    	</bean>
    	
    	
    	<bean name="cb" class="com.anthony.injection.CollectionBean">
    		
    		<property name="map">
    			<map>
    				<entry key="user" value="root"></entry>
    				<entry key="password" value="123456"></entry>
    				<entry key-ref="user" value-ref="user"></entry>
    			</map>
    		</property>
    		
    	</bean>
    </beans>

运行结果

CollectionBean [arr=null, li=null, map={user=root, password=123456, User [name=tom, age=18]=User [name=tom, age=18]}, pro=null]

**5.Properties类型注入**

其实Properties就是一个HashMap子类对象，只不过键值对存储都是字符串，下来来一个简单例子。

<?xml version="1.0" encoding="UTF-8"?>
    
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    	   xmlns="http://www.springframework.org/schema/beans" 
    	   xsi:schemaLocation="http://www.springframework.org/schema/beans 
    	   http://www.springframework.org/schema/beans/spring-beans.xsd ">
    	
    	<bean name="user" class="com.anthony.bean.User">
    		<property name="name" value="tom"></property>
    		<property name="age" value="18"></property>
    	</bean>
    	
    	
    	<bean name="cb" class="com.anthony.injection.CollectionBean">
    		
    		<property name="pro">
    			<props>
    				<prop key="user">root</prop>
    				<prop key="password">123456</prop>
    				<prop key="url">jdbc:mysql://localhost:3306/j2ee</prop>
    			</props>
    			
    		</property>
    		
    	</bean>
    </beans>

运行结果如下

CollectionBean [arr=null, li=null, map=null, pro={user=root, password=123456, url=jdbc:mysql://localhost:3306/j2ee}]

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