Spring注入方式(2)

3、引用其他bean

　　Bean经常需要相互协作完成应用程序的功能，bean之间必须能够互相访问，就必须在bean配置之间指定对bean的引用，可以通过节点<ref>或者ref来为bean属性指定对bean的引用，也可以在属性或者构造器里包含bean的声明，这样bean称为内部bean。

bean中引用其他bean,其中Car为对象。

 1 <!-- 通过构造方法配置bean属性 -->
 2     <bean id="car" class="hello.Car">
 3     <constructor-arg value="Audi" index="0"></constructor-arg>
 4     <constructor-arg value="ShangHai" index="1"></constructor-arg>
 5     <constructor-arg value="300000" type="double" ></constructor-arg>
 6         
 7 </bean>
 8 
 9 <bean id="person" class="hello.Person">
10     <property name="name" value = "Tom"></property>
11     <property name="age" value = "24"></property>
12     <property name="car" ref="car"></property>
13 </bean>

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内部bean

 1 <bean id="person" class="hello.Person">
 2         <property name="name" value = "Tom"></property>
 3         <property name="age" value = "24"></property>
 4         <!--  
 5         <property name="car" ref="car"></property>-->
 6         
 7         <!-- 内部bean -->
 8         <property name="car">
 9             <!-- 内部bean不能被外部bean使用 -->
10             <bean id="car3" class="hello.Car">
11                 <constructor-arg value="Ford"></constructor-arg>
12                 <constructor-arg value="Changan"></constructor-arg>
13                 <constructor-arg value="200000" type="double"></constructor-arg>
14                 
15             </bean>
16         </property>
17 </bean>

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4、集合属性

在Spring中可以通过<list>、<set>或者<map>来配置集合属性。

通过list配置集合属性

Person.java

 1 package com.spring;
 2 
 3 import java.util.List;
 4 
 5 public class Person {
 6     private String name;
 7     private int age;
 8     private List<Car> cars;
 9     public String getName() {
10         return name;
11     }
12     public void setName(String name) {
13         this.name = name;
14     }
15     public int getAge() {
16         return age;
17     }
18     public void setAge(int age) {
19         this.age = age;
20     }
21     public List<Car> getCars() {
22         return cars;
23     }
24     public void setCars(List<Car> cars) {
25         this.cars = cars;
26     }
27     @Override
28     public String toString() {
29         return "Person [name=" + name + ", age=" + age + ", cars=" + cars + "]";
30     }
31     
32     
33     
34 }

View Code

Car.java

 1 package com.spring;
 2 
 3 public class Car {
 4     private String brand;
 5     private double price;
 6     private int maxSpeed;
 7     public String getBrand() {
 8         return brand;
 9     }
10     public void setBrand(String brand) {
11         this.brand = brand;
12     }
13     public double getPrice() {
14         return price;
15     }
16     public void setPrice(double price) {
17         this.price = price;
18     }
19     public int getMaxSpeed() {
20         return maxSpeed;
21     }
22     public void setMaxSpeed(int maxSpeed) {
23         this.maxSpeed = maxSpeed;
24     }
25     @Override
26     public String toString() {
27         return "Car [brand=" + brand + ", price=" + price + ", maxSpeed=" + maxSpeed + "]";
28     }
29     
30 }

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beans-collection.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xmlns:util="http://www.springframework.org/schema/util"
 5     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
 6         http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd">
 7     
 8     <bean id="car1" class="com.spring.Car">
 9         <property name="brand" value="audi"></property>
10         <property name="price" value="400000"></property>
11         <property name="maxSpeed" value="240"></property>
12     </bean>
13     
14     <bean id="car2" class="com.spring.Car">
15         <property name="brand" value="baoma"></property>
16         <property name="price" value="700000"></property>
17         <property name="maxSpeed" value="270"></property>
18     </bean>
19     
20     <bean id="person" class="com.spring.Person">
21         <property name="name" value="Jerry"></property>
22         <property name="age" value="41"></property>
23         <property name="cars">
24             <list>
25                 <ref bean="car1" />
26                 <ref bean="car2" />
27             </list>
28         </property>
29     </bean>
30 </beans>

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结果：

通过map配置属性

Person.java

 1 package com.spring;
 2 
 3 import java.util.Map;
 4 
 5 public class Person {
 6     private String name;
 7     private int age;
 8     private Map<String, Car> carMap;
 9     public String getName() {
10         return name;
11     }
12     public void setName(String name) {
13         this.name = name;
14     }
15     public int getAge() {
16         return age;
17     }
18     public void setAge(int age) {
19         this.age = age;
20     }
21     public Map<String, Car> getCarMap() {
22         return carMap;
23     }
24     public void setCarMap(Map<String, Car> carMap) {
25         this.carMap = carMap;
26     }
27     @Override
28     public String toString() {
29         return "Person [name=" + name + ", age=" + age + ", carMap=" + carMap + "]";
30     }
31 }

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beans-collection

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xmlns:util="http://www.springframework.org/schema/util"
 5     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
 6         http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd">
 7     
 8     <bean id="car1" class="com.spring.Car">
 9         <property name="brand" value="audi"></property>
10         <property name="price" value="400000"></property>
11         <property name="maxSpeed" value="240"></property>
12     </bean>
13     
14     <bean id="car2" class="com.spring.Car">
15         <property name="brand" value="baoma"></property>
16         <property name="price" value="700000"></property>
17         <property name="maxSpeed" value="270"></property>
18     </bean>
19     
20     <bean id="person" class="com.spring.Person">
21         <property name="name" value="Jerry"></property>
22         <property name="age" value="41"></property>
23         <property name="carMap">
24             <map>
25                 <entry key="1" value-ref="car1"></entry>
26                 <entry key="2" value-ref="car2"></entry>
27             </map>
28         </property>
29     </bean>
30 </beans>

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结果：

配置Set属性，和配置list一样。

5、p名字空间注入，也需要setter方法。

Student.java

 1 package com.spring;
 2 
 3 public class Student {
 4     private String name;
 5     private String number;
 6     
 7     public String getName() {
 8         return name;
 9     }
10     public void setName(String name) {
11         this.name = name;
12     }
13     public String getNumber() {
14         return number;
15     }
16     public void setNumber(String number) {
17         this.number = number;
18     }
19     
20     @Override
21     public String toString() {
22         return "Student [name=" + name + ", number=" + number + "]";
23     }
24     
25     
26 }

View Code

Main.java

 1 package com.spring;
 2 
 3 import org.springframework.context.ApplicationContext;
 4 import org.springframework.context.support.ClassPathXmlApplicationContext;
 5 
 6 public class Main {
 7     public static void main(String[] args) {
 8         ApplicationContext ac = new ClassPathXmlApplicationContext("beans-p.xml");
 9         Student student = (Student) ac.getBean("student");
10         System.out.println(student);
11     }
12 }

View Code

beans-p.xml

1 <?xml version="1.0" encoding="UTF-8"?>
2 <beans xmlns="http://www.springframework.org/schema/beans"
3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4     xmlns:p="http://www.springframework.org/schema/p"
5     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
6     
7     <bean id="student" class="com.spring.Student" p:name="Merry" p:number="1120141314"></bean>
8 
9 </beans>

View Code

执行结果

6、property注入

Student.java

 1 package com.spring;
 2 
 3 import java.util.Properties;
 4 
 5 public class Student {
 6     private String name;
 7     private String number;
 8     private Properties properties;
 9     
10     public String getName() {
11         return name;
12     }
13     public void setName(String name) {
14         this.name = name;
15     }
16     public String getNumber() {
17         return number;
18     }
19     public void setNumber(String number) {
20         this.number = number;
21     }
22     public Properties getProperties() {
23         return properties;
24     }
25     public void setProperties(Properties properties) {
26         this.properties = properties;
27     }
28     @Override
29     public String toString() {
30         return "Student [name=" + name + ", number=" + number + ", properties=" + properties + "]";
31     }
32     
33     
34     
35     
36     
37     
38 }

View Code

beans-p.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xmlns:p="http://www.springframework.org/schema/p"
 5     xmlns:util="http://www.springframework.org/schema/util"
 6     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
 7         http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.3.xsd">
 8     <bean id="student" class="com.spring.Student">
 9         <property name="name" value="Merry"></property>
10         <property name="number" value="1120141213"></property>
11         <property name="properties" >
12             <props>
13                 <prop key="user">root</prop>
14                 <prop key="psw">1234</prop>
15                 <prop key="jdbcUrl">jdbc:mysql:///test</prop>
16                 <prop key="driverClass">com.mysql.jdbc.Driver</prop>
17             </props>
18         </property>
19         
20     </bean>
21 </beans>

View Code

执行结果

7、c命名空间注入

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原文地址：https://www.cnblogs.com/Hxinguan/p/5936039.html