13.@PropertySource@ImportResource@Bean注解

Posted on 2018-01-10 Edited on 2023-02-17 In SpringBoot

1. @PropertySource

1.1 为使用要使用@PropertySource

项目配置的注入，所有的配置都是写在appliaction.properties或application.yml文件里，那么如果不想写在这里面怎么处理呢使用@PropertySource可以解决

仅验证可以使用.properties配置文件，未验证.yml配置文件

package com.example.vo;

import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;
import org.springframework.validation.annotation.Validated;

import lombok.Data;

@Component
@ConfigurationProperties(prefix = "person")
@Data
@Validated
@PropertySource("classpath:person.properties")
public class Person {

	private Integer id;
	private String userName;
	private Integer age;
	private String[] hobby;
	private List<String> course;
	private Set<String> book;
	private Map<String, String> score;
	private Date birthday;

}

person.properties:

server.port=8890

#config
person.id=2
person.user-name=xiaozhang
person.age=${random.int(1,100)}
person.hobby=reading,exercise,writing
person.course=literature,mathematics,geography,chemistry,${course}
person.book=book1,book2,book3,${person.id}
person.score.math=90
person.score.chemistry=95
person.birthday.time=1610890991736

course: biology

package com.example.demo;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import com.example.vo.Person;

@SpringBootTest
class ApplicationTests {
	
	@Autowired
	private Person person;

	@Test
	void contextLoads() {
		System.out.println(person);
        // Person(id=2, userName=xiaozhang, age=61, hobby=[reading, exercise, writing], course=[literature, mathematics, geography, chemistry, biology], book=[book1, book2, book3, 2], score={chemistry=95, math=90}, birthday=Sun Jan 17 21:43:11 CST 2021)
	}
}

(1) @PropertySource只要使用在能扫描到的地方就可以，例如: Application.java

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.PropertySource;

@SpringBootApplication
@ComponentScan("com.example")
@PropertySource("classpath:person.properties")
public class Application {

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

}

1.2 注入优先级的问题

所在的配置都是优先注入appliaction.properties或application.yml里面的数据，自己创建的配置文件properties优先级较低

如果要不一样，必须修改配置文件引入的前缀

server.port=8890

#config
person.id=100
person.user-name=xiaozhang
person.age=${random.int(1,100)}
person.hobby=reading,exercise,writing
person.course=literature,mathematics,geography,chemistry,${course}
person.book=book1,book2,book3,${person.id}
person.score.math=90
person.score.chemistry=98
person.birthday.time=1610890991736

course: biology

ApplicationTests的输出:

Person(id=100, userName=xiaozhang, age=94, hobby=[reading, exercise, writing], course=[literature, mathematics, geography, chemistry, biology], book=[book1, book2, book3, 100], score={math=90, chemistry=98}, birthday=Sun Jan 17 21:43:11 CST 2021)

2.@ImportResource

2.1 为什么要使用@ImportResource

从上面所有的配置中可以看出我们没有使用以前的spring的xml的配置方法，如果还是要使用spring里面的xml的配置方式怎么办，使用@ImportResource

创建Student.java，没有加@Component注解

package com.example.vo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student {
	private Integer id;
	private String name;
	private Integer age;
}

创建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"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

	<!-- 声明Student对象 -->
	<bean id="student" class="com.example.vo.Student">
		<property name="id" value="1"></property>
		<property name="name" value="Steven"></property>
	</bean>
	
</beans>

启动类Application.java，添加@ImportResource注解，添加在能被Spring扫描到的类上就可以

package com.example.demo;

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

@SpringBootApplication
@ComponentScan("com.example")
//@ImportResource("classpath:beans.xml")
@ImportResource(value = {"classpath:beans.xml"})
public class Application {

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

}

测试类ApplicationTests

package com.example.demo;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import com.example.vo.Person;
import com.example.vo.Student;

@SpringBootTest
class ApplicationTests {
	
	@Autowired
	private Student student;

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

<bean id="student">和private Student student，id值和属性名可以不相等

3.@Bean

创建Teacher.java

package com.example.vo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Teacher {

	private Integer id;
	private String name;
	private String subject;
	
}

创建TeacherConfig.java

package com.example.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.example.vo.Teacher;

@Configuration
public class TeacherConfig {

	@Bean("teacher1")
	public Teacher getTeacher1() {
		return new Teacher(1, "Tom", "physics");
	}
	
	@Bean("teacher2")
	public Teacher getTeacher2() {
		return new Teacher(2, "Jerry", "chemistry");
	}

	@Bean("teacher3")
	public Teacher getTeacher3(Teacher teacher2) {
		teacher2.setSubject("math");
		return teacher2;
	}

	/*
	@Bean加在方法上，默认形参会带有@Autowired，同时可以使用@Qualifier指定要注入的对象
	
	@Bean("teacher3")
	public Teacher getTeacher3(@Autowired @Qualifier("teacher1") Teacher teacher2) {
		teacher2.setSubject("math");
		return teacher2;
	}

	ApplicationTests类的测试方法输出: Teacher(id=1, name=Tom, subject=math)
	*/
	
}

ApplicationTests.java

package com.example.demo;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.test.context.SpringBootTest;

import com.example.vo.Teacher;

@SpringBootTest
class ApplicationTests {
	
	@Autowired
	@Qualifier("teacher1")
	private Teacher teacher;
	
	@Autowired
	private Teacher teacher1;

	@Test
	void contextLoads() {
		System.out.println(teacher);
		System.out.println(teacher1);
		// Teacher(id=1, name=Tom, subject=physics)
		// Teacher(id=1, name=Tom, subject=physics)

		System.out.println(teacher3);
		// Teacher(id=2, name=Jerry, subject=math)

	}
}