Spring注解驱动开发实战 | 第十二篇：属性赋值-@Value赋值和@PropertySource使用

在com.wsc.config包下创建MainConfigOfPropertyValues.java，添加@Configuration，使其作为配置文件，并使用@Bean注册Person到容器。同时使用@PropertySource(value={"classpath:/person.properties"})将配置文件加载到容器中

package com.wsc.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import com.wsc.bean.Person;

//使用@PropertySource读取外部配置文件中的k/v保存到运行的环境变量中;加载完外部的配置文件以后使用${}取出配置文件的值
@PropertySource(value={"classpath:/person.properties"})
@Configuration
public class MainConfigOfPropertyValues {
	
	@Bean
	public Person person(){
		return new Person();
	}

}

在Person.java中添加属性赋值

package com.wsc.bean;

import org.springframework.beans.factory.annotation.Value;

public class Person {
	
	//使用@Value赋值；
	//1、基本数值
	//2、可以写SpEL； #{}
	//3、可以写${}；取出配置文件【properties】中的值（在运行环境变量里面的值）
	
	@Value("张三")
	private String name;
	@Value("#{20-2}")
	private Integer age;
	
	@Value("${person.nickName}")
	private String nickName;
	
	
	
	public String getNickName() {
		return nickName;
	}
	public void setNickName(String nickName) {
		this.nickName = nickName;
	}
	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;
	}
	
	public Person(String name, Integer age) {
		super();
		this.name = name;
		this.age = age;
	}
	public Person() {
		super();
	}

	public String toString() {
		return "Person [name=" + name + ", age=" + age + ", nickName=" + nickName + "]";
	}

	
	
	
}

在/src/main/resources下创建person.properties，内容如下

person.nickName=炊烟袅袅

在com.wsc.test下创建IOCTest_PropertyValue.java，添加testPropertyValue方法

package com.wsc.test;

import org.junit.Test;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.core.env.ConfigurableEnvironment;

import com.wsc.bean.Person;
import com.wsc.config.MainConfigOfPropertyValues;



public class IOCTest_PropertyValue {
	AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfigOfPropertyValues.class);
	@Test
	public void testPropertyValue(){
		printBeans(applicationContext);
		System.out.println("=============");
		
		Person person = (Person) applicationContext.getBean("person");
		System.out.println(person);
		
		
		ConfigurableEnvironment environment = applicationContext.getEnvironment();
		String property = environment.getProperty("person.nickName");
		System.out.println(property);
		applicationContext.close();
	}
	
	private void printBeans(AnnotationConfigApplicationContext applicationContext){
		String[] definitionNames = applicationContext.getBeanDefinitionNames();
		for (String name : definitionNames) {
			System.out.println(name);
		}
	}

}

运行testPropertyValue方法结果:

--------------------------------

源码下载