SpringBoot 01: JavaConfig + @ImportResource + @PropertyResource _生活百科

【SpringBoot 01: JavaConfig + @ImportResource + @PropertyResource】springboot的前置知识：通过注解创建对象和读取配置文件

1. JavaConfig设计思想

使用java类作为xml配置文件的替代，是配置spring容器的纯java的方式
可以创建java对象并把对象注入到spring容器中

注解实现

@Configuration ：放在一个类的上面，表示这个类是作为配置文件使用的
@Bean：放在返回值是对象的方法上，容器启动时，声明对象，并把对象注入到容器中
上面两个注解配套使用

代码实现

package com.example.springboot.configuration;import com.example.springboot.model.Student;import org.springframework.context.annotation.*;@Configurationpublic class SpringConfig {@Beanpublic Student getStudent(){Student student = new Student();student.setName("橘子");student.setAge(18);return student;}@Bean(name = "student")public Student getStudentByBeanName(){Student student = new Student();student.setName("饺子");student.setAge(21);return student;}}

测试代码

package com.example.springboot.testspringconfig;import com.example.springboot.configuration.SpringConfig;import com.example.springboot.model.Student;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.annotation.AnnotationConfigApplicationContext;public class TestSpringConfig {@Testpublic void testSpringConfig(){ApplicationContext applicationContext = new AnnotationConfigApplicationContext(SpringConfig.class);Student student = (Student) applicationContext.getBean("student");//未在@Bean中指定对象名称时，从方法名(小驼峰命名规范)来获取对象//Student student = (Student) applicationContext.getBean("getStudent");System.out.println("获取到的对象: " + student);}}

2. @ImportResource设计思想

导入其他的xml配置文件，等于在xml 使用如下import标签

<import resources="其他配置文件"/>代码实现

SpringConfig类

package com.example.springboot.configuration;import org.springframework.context.annotation.*;@ImportResource(value = "https://www.huyubaike.com/biancheng/classpath:applicationContext.xml")public class SpringConfig {}

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="cat" class="com.example.springboot.model.Cat"><property name="catCard" value="https://www.huyubaike.com/biancheng/0010"/><property name="catName" value="https://www.huyubaike.com/biancheng/tomcat"/></bean></beans>

测试代码

package com.example.springboot.testspringconfig;import com.example.springboot.configuration.SpringConfig;import com.example.springboot.model.Cat;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.annotation.AnnotationConfigApplicationContext;public class TestSpringConfig {@Testpublic void testImportResource(){ApplicationContext applicationContext = new AnnotationConfigApplicationContext(SpringConfig.class);Cat cat = (Cat) applicationContext.getBean("cat");System.out.println("获取到的对象: " + cat);}}

3. @PropertyResource设计思想