Spring 基于XML的构造函数和setter方法的依赖注入

快来打我* 2022-04-25 05:06 194阅读 0赞

### 文章目录 ###

*   *  Spring 依赖注入
     *   *  Spring 基于构造函数的依赖注入
         *  Spring 基于setter方法的依赖注入
         *  Spring 注入内部 Beans

## Spring 依赖注入 ##

Spring框架的核心功能之一就是通过依赖注入的方式来管理Bean之间的依赖关系。

### Spring 基于构造函数的依赖注入 ###

*  配置

<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="userId1" class="com.cc.study.di.User" lazy-init="true">
            <constructor-arg  type="java.lang.Integer" value="1"></constructor-arg>
            <constructor-arg type="java.lang.String" value="bbb"></constructor-arg>
        </bean>
        <bean id="userId2" class="com.cc.study.di.User" lazy-init="true">
            <constructor-arg  name="uid" value="1"></constructor-arg>
            <constructor-arg name="username" value="bbb"></constructor-arg>
        </bean>
    
        <bean id="userId3" class="com.cc.study.di.User" lazy-init="true">
            <constructor-arg index="0"  value="1"></constructor-arg>
            <constructor-arg index="1"  value="2"></constructor-arg>
        </bean>
    
    </beans>

*  User

package com.cc.study.di;
    
    public class User {
    
    	private Integer uid;
    	private String username;
    	private Integer age;
    
    	public User(Integer uid, String username) {
    		super();
    		this.uid = uid;
    		this.username = username;
    		System.out.println("uid:" + uid + ", username:" + username);
    	}
    
    	public User(String username, Integer age) {
    		super();
    		this.username = username;
    		this.age = age;
    		System.out.println("username:" + username + ", age:" + age);
    	}
    }

*  测试

@Test
        public void demo07(){
            String xmlPath = "di4.xml";
            ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
            User user = applicationContext.getBean("userId1",User.class);
        }

![在这里插入图片描述][20190501210303177.png]

@Test
        public void demo08(){
            String xmlPath = "di4.xml";
            ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
            User user = applicationContext.getBean("userId2",User.class);
        }

![在这里插入图片描述][20190501210328689.png]

@Test
        public void demo09(){
            String xmlPath = "di4.xml";
            ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
            User user = applicationContext.getBean("userId3",User.class);
        }

![在这里插入图片描述][20190501210356368.png]

### Spring 基于setter方法的依赖注入 ###

*  配置

*  Person

public class Person {
        private String pname;
        private Integer age;
        private Address homeAddr;
        private Address companyAddr;
    
        public String getPname() {
            return pname;
        }
    
        public void setPname(String pname) {
            this.pname = pname;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public void setAge(Integer age) {
            this.age = age;
        }
    
        public Address getHomeAddr() {
            return homeAddr;
        }
    
        public void setHomeAddr(Address homeAddr) {
            this.homeAddr = homeAddr;
        }
    
        public Address getCompanyAddr() {
            return companyAddr;
        }
    
        public void setCompanyAddr(Address companyAddr) {
            this.companyAddr = companyAddr;
        }
    }

*  Address

public class Address {
    
        private String addr;
        private String tel;
    
        public String getAddr() {
            return addr;
        }
    
        public void setAddr(String addr) {
            this.addr = addr;
        }
    
        public String getTel() {
            return tel;
        }
    
        public void setTel(String tel) {
            this.tel = tel;
        }
    
        @Override
        public String toString() {
            return "Address{" +
                    "addr='" + addr + '\'' +
                    ", tel='" + tel + '\'' +
                    '}';
        }
    }

*  测试

@Test
        public void demo10(){
            String xmlPath = "di5.xml";
            ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
            Person p = applicationContext.getBean("personId",Person.class);
            System.out.println(p.getPname());
            System.out.println(p.getAge());
            System.out.println(p.getCompanyAddr());
            System.out.println(p.getHomeAddr());
        }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70]

### Spring 注入内部 Beans ###

*  配置格式

*  配置

*  测试

@Test
        public void demo11(){
            String xmlPath = "di6.xml";
            ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
            Person p = applicationContext.getBean("personId",Person.class);
            System.out.println(p.getPname());
            System.out.println(p.getAge());
            System.out.println(p.getCompanyAddr());
            System.out.println(p.getHomeAddr());
        }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70 1]

[20190501210303177.png]: /images/20220210/6f2964627f134370aa2fab4fb31db3a1.png
[20190501210328689.png]: /images/20220210/946d4038a746434782c51345df9a48cc.png
[20190501210356368.png]: /images/20220210/a2eed433e009485699e140004e5312ef.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70]: /images/20220210/b353f66e590049ffa61815a66d0d88de.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70 1]: /images/20220210/6e9a6e39957a49919b7c2efba81667ba.png