springBean参数注入的几个方法

1、普通方式注入

applicationContext.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.xsd">

     <bean id="person" class="com.xiaostudy.service.PersonImple">
         <property name="id" value="2018"></property>
         <property name="name" value="xiaostudy"></property>
         <property name="age" value="23"></property>
     </bean>
 </beans>

PersonImple.java

 package com.xiaostudy.service;

 public class PersonImple implements Person {

     private Integer id;
     private String name;
     private Integer age;

     public Integer getId() {
         return id;
     }

     public void setId(Integer id) {
         this.id = id;
     }

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public Integer getAge() {
         return age;
     }

     public void setAge(Integer age) {
         this.age = age;
     }

     @Override
     public String toString() {
         return "PersonImple [id=" + id + ", name=" + name + ", age=" + age + "]";
     }

 }

2、通过构造方法的注入，name为参数名称

applicationContext.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.xsd">

     <bean id="person" class="com.xiaostudy.service.PersonImple">
         <constructor-arg name="id" value="2018"></constructor-arg>
         <constructor-arg name="name" value="xiaostudy"></constructor-arg>
         <constructor-arg name="age" value="23"></constructor-arg>
     </bean>
 </beans>

PersonImple.java

 package com.xiaostudy.service;

 public class PersonImple implements Person {

     private Integer id;
     private String name;
     private Integer age;

     public PersonImple(Integer id, String name, Integer age) {
         this.id = id;
         this.name = name;
         this.age = age;
     }

     public Integer getId() {
         return id;
     }

     public void setId(Integer id) {
         this.id = id;
     }

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public Integer getAge() {
         return age;
     }

     public void setAge(Integer age) {
         this.age = age;
     }

     @Override
     public String toString() {
         return "PersonImple [id=" + id + ", name=" + name + ", age=" + age + "]";
     }

 }

3、也是通过构造方法注入，index为参数索引的位置

applicationContext.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.xsd">

     <bean id="person" class="com.xiaostudy.service.PersonImple">
         <constructor-arg index="0" value="2018"></constructor-arg>
         <constructor-arg index="1" value="xiaostudy"></constructor-arg>
         <constructor-arg index="2" value="23"></constructor-arg>
     </bean>
 </beans>

4、也是通过构造方法注入，type是参数的数据类型

applicationContext.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.xsd">

     <bean id="person" class="com.xiaostudy.service.PersonImple">
         <constructor-arg type="java.lang.Integer" value="2018" index="0"></constructor-arg>
         <constructor-arg type="java.lang.String" value="xiaostudy" index="1"></constructor-arg>
         <constructor-arg type="java.lang.Integer" value="23" index="2"></constructor-arg>
     </bean>
 </beans>

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