使用@Qualifier可以分別為同樣類型的Bean分別注入不同的依賴值。看個例子：

Student.java：

package com.sap;public class Student {private Integer age;private String name;public void setAge(Integer age) {this.age = age;} public Integer getAge() {return age;}public void setName(String name) {this.name = name;} public String getName() {return name;} }

Profile：

package com.sap;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; public class Profile {@Autowired@Qualifier("student1")private Student student;public Profile(){System.out.println("Inside Profile constructor." );}public void printAge() {System.out.println("Age : " + student.getAge() );}public void printName() {System.out.println("Name : " + student.getName() );} }

Main.app:

package com.sap;import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class MainApp {public static void main(String[] args) {ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");Profile profile = (Profile) context.getBean("profile");profile.printAge();profile.printName();} }

Beans.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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans-3.0.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context-3.0.xsd"><context:annotation-config/><!-- Definition for profile bean --><bean id="profile" class="com.sap.Profile"></bean><!-- Definition for student1 bean --><bean id="student1" class="com.sap.Student"><property name="name" value="Zara" /><property name="age" value="11"/></bean><!-- Definition for student2 bean --><bean id="student2" class="com.sap.Student"><property name="name" value="Nuha" /><property name="age" value="2"/></bean></beans>

輸出：

如果把profile類里的id改成student2：

輸出：

要獲取更多Jerry的原創文章，請關注公眾號"汪子熙":

總結

以上是生活随笔為你收集整理的Spring 基于注解(annotation)的配置之@Qualifier注解的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。