spinrgboot配置之@PropertySource和@ImportResource

一、@PropertySource：用于加载指定的配置文件

比如我们在resource下新建一个person.properties

person.username=李四
person.age=12
person.email=zhangsan@qq.com
person.maps.k1=v1
person.maps.k2=v2
person.lists=a,b,c
person.dog.name=tom
person.dog.age=2

在person.java中

package com.gong.springboot.bean;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.Map;

//将配置文件中的属性映射到组件中
//prefix：表示配置文件中的哪个下面的属性进行一一映射
@Component
@ConfigurationProperties(prefix="person")
@PropertySource(value={"classpath:person.properties"})
public class Person {
    /**<bean clas="Person">
     *      <property name="username" value="字面量/${key}从环境变量中获取值/#{}spel"></property>
     * </bean>
     *
     */
    //@Value("${person.username}")
    private String username;
    //@Value("#{11*2}")
    private Integer age;
    //@Value("test@qq.com")
    private String email;
    private Map<String,Object> maps;
    private List<Object> lists;
    private Dog dog;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Integer getAge() {
        return age;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Map<String, Object> getMaps() {
        return maps;
    }

    public void setMaps(Map<String, Object> maps) {
        this.maps = maps;
    }

    public List<Object> getLists() {
        return lists;
    }

    public void setLists(List<Object> lists) {
        this.lists = lists;
    }

    public Dog getDog() {
        return dog;
    }

    public void setDog(Dog dog) {
        this.dog = dog;
    }

    @Override
    public String toString() {
        return "Person{" +
                "username='" + username + ''' +
                ", age=" + age +
                ", email='" + email + ''' +
                ", maps=" + maps +
                ", lists=" + lists +
                ", dog=" + dog +
                '}';
    }
}

注意：@ConfigurationProperties(prefix="person")不要注释掉。同时主配置文件中不能有person.properties相同的配置，否则自己定义的配置就会失效。进行测试：

Person{username='李四', age=12, email='zhangsan@qq.com', maps={k2=v2, k1=v1}, lists=[a, b, c], dog=Dog{name='tom', age=2}}

二、@ImportResource：导入spring的配置文件，让配置文件的内容生效

在com.gong.springboot下新建一个service包，在该包下新建，HelloWorldService.java

package com.gong.springboot.Service;

public class HelloWorldService {
}

在resources文件加下新建beans.xml。将HelloWorldService注入到IOC容器中

<?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="helloWorldService" class="com.gong.springboot.Service.HelloWorldService"></bean>
</beans>

在主配置类中：

package com.gong.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ImportResource;

@ImportResource(locations = {"classpath:beans.xml"})
@SpringBootApplication
public class Myspringboot2Application {

    public static void main(String[] args) {
        SpringApplication.run(Myspringboot2Application.class, args);
    }

}

在测试文件中：

package com.gong.springboot;

import com.gong.springboot.Service.HelloWorldService;
import com.gong.springboot.bean.Person;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class Myspringboot2ApplicationTests {

    @Autowired
    Person person;

    @Autowired
    ApplicationContext ioc;

    @Test
    public void contextLoads() {
        System.out.println(person);
    }

    @Test
    public void testService(){
        Boolean b = ioc.containsBean("helloWorldService");
        System.out.println(b);
    }
}

运行测试：在控制台可以看到输出true。如果不在主配置类中使用ImportResource注解标识位置，则输出的为false。

三、springboot推荐给容器中添加组件的方式：使用全注解的方式

在com.gong.springboot下新建一个config包，在该包下新建MyAppConfig.java

package com.gong.springboot.config;

import com.gong.springboot.Service.HelloWorldService;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

//指明当前类是一个配置类，替代了之前的spring配置文件，也就是beans.xml
@Configuration
public class MyAppConfig {
    //Bean注解：将方法的返回值添加到容器中，组件默认的id就是方法名，也就是helloWorldService
    @Bean
    public HelloWorldService helloWorldService(){
        return new HelloWorldService();
    }
}

注释掉主配置类中的@ImportResource再进行测试：在控制台还是可以输出true。