Hi ! 我是小小,今天是本周的第三篇,Spring Boot 中使用@Value读取配置文件

配置文件配置

直接配置
在src/main/resources下添加配置文件,application.properties 修改端口号等。

#端口号
server.port=8089

如果要是开发环境,测试环境,等环境配置需要做如下配置
在src/main/resources下添加,application-pro.properties, application-dev.properties 和 application.properties 三个文件,
内容如下
application.properties

spring.profiles.active=dev

application-pro.properties

#端口号
server.port=80
#自定义端口号读取
my.name=pzr.dev

application-dev.properties

#端口号
server.port=8089
#自定义端口号读取
my.name=pzr.pro

单spplication.properties 设置spring.profiles.active=dev的时候,说明指定使用application-dev.properties 文件进行配置。

配置文件参数读取

注解方式读取

@PropertySource

@PropertySource 配置文件路径设置,在类上添加注解,如果在默认路径下可以不添加该注解。

@PropertySource({"classpath:config/my.properties","classpath:config/config.properties"})
public class TestController

@Value 属性名,在属性名上添加注解

@Value("${my.name}")
private String myName;

配置文件中配置集合类(Map,List) @Value 注入map,List

yaml格式

@Value("#{'{list}'.split(',')}")
private List<String> list;

@Value("#{{maps}}")  
private Map<String,String> maps;

@Value("#{${redirectUrl}}")
private Map<String,String> redirectUrl;

配置文件

list: topic1,topic2,topic3
maps: "{key1: 'value1', key2: 'value2'}"
redirectUrl: "{sso_client_id: '{id}',sso_client_secret: '{secret}',redirect_url: '${client.main.url.default}'}"

举俩例子

例子一

配置文件application.properties

spring.application.name=springbootdemo
server.port=8080
mail.username=application-duan
mail.password=application-duan123456

启动类

package com.dxz.property5;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;

@SpringBootApplication
public class TestProperty5 {

    public static void main(String[] args) {
        //SpringApplication.run(TestProperty1.class, args);
        new SpringApplicationBuilder(TestProperty5.class).web(true).run(args);

    }
}

测试类

package com.dxz.property5;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.PropertySource;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/task")
//@PropertySource("classpath:mail.properties")
public class TaskController {

    @Value("{mail.username}")
    private String userName;

    @Value("{mail.password}")
    private String password;

    @RequestMapping(value = { "/", "" })
    public String hellTask() {
        System.out.println("userName:" + userName);
        System.out.println("password:" + password);
        return "hello task !!";
    }

}

结果

userName:application-duan
password:application-duan123456

例子二

使用 @Value + @PropertySource读取其他配置文件,多个内容
读取mail.properties 配置

package com.dxz.property5;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.PropertySource;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/task")
@PropertySource("classpath:mail.properties")
public class TaskController {
    @Value("{mail.smtp.auth}")
    private String userName;

    @Value("{mail.from}")
    private String password;

    @RequestMapping(value = { "/", "" })
    public String hellTask() {
        System.out.println("userName:" + userName);
        System.out.println("password:" + password);
        return "hello task !!";
    }

}

结果

userName:false
password:me@localhost

按照对象映射方式读取

  1. 首先建立对象与配置文件映射关系
  2. 方法中使用自动注入方式,对象注入,调用get获取属性值
    测试类
package com.dxz.property6;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.PropertySource;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/task")
@PropertySource({ "classpath:mail.properties", "classpath:db.properties" })
public class TaskController {

    // 在application.properties中的文件,直接使用@Value读取即可,applicarion的读取优先级最高
    @Value("{mail.username}")
    private String myName;

    // 如果多个文件有重复的名称的属性话,最后一个文件中的属性生效
    @Value("{mail.port}")
    private String port;

    @Value("${db.username}")
    private String dbUserName;

    @Autowired
    ObjectProperties objectProperties;

    @RequestMapping("/test")
    @ResponseBody
    String test() {
        String result = "myName:" + myName + "n port:" + port + "n   dbUserName:" + dbUserName + "n   objectProperties:"
                + objectProperties;
        System.out.println("result:=" + result);
        return result;
    }


}

启动类

package com.dxz.property6;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;

@SpringBootApplication
public class TestProperty6 {

    public static void main(String[] args) {
        //SpringApplication.run(TestProperty1.class, args);
        new SpringApplicationBuilder(TestProperty6.class).web(true).run(args);

    }
}

ObjectProperties.java

package com.dxz.property6;

import java.util.ArrayList;
import java.util.List;

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

/**
 * 配置文件映射对象
 * @author DELL
 */
@Component
@PropertySource("classpath:config/object.properties")
@ConfigurationProperties(prefix = "obj")
public class ObjectProperties {

    private String name;
    private String age;
    // 集合必须初始化,如果找不到就是空集合,会报错
    private List<String> className = new ArrayList<String>();

    public List<String> getClassName() {
        return className;
    }

    public void setClassName(List<String> className) {
        this.className = className;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAge() {
        return age;
    }

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

    @Override
    public String toString() {
        return "ObjectProperties [name=" + name + ", age=" + age + ", className=" + className + "]";
    }


}

object.properties

#自定义属性读取
obj.name=obj.name
obj.age=obj.age
obj.className[0]=obj.className[0]
obj.className[1]=obj.className[1]

db.properties

db.username=admin
db.password=admin123456
mail.port=2555

访问 http://localhost:8080/task/test/

result:=myName:application-duan
 port:2555
   dbUserName:admin
   objectProperties:ObjectProperties [name=obj.name, age=obj.age, className=[obj.className[0], obj.className[1]]]

关于作者

我是小小,一枚生于二线活在一线城市的程序猿,我是小小,我们下期再见。