SpringBoot开发使用篇-02-配置文件数据相关使用

一、简单获取配置文件的数据

application.yml配置文件

servers:
  ipAddress: 127.0.0.1
  port: 1234
  timeout: -1

 创建配置文件的对应实体类

package com.gg.config;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

/**
 * @Author: {LZG}
 * @ClassName: ServerConfig
 * @Description: TODO
 * @Date: 2022/4/21 22:59
 **/
@Component
@Data
@ConfigurationProperties(prefix = "servers")
public class ServerConfig {
    private String ipAddress;
    private int port;
    private long timeout;
}

 作用：@ConfigurationProperties：快速、方便的将配置文件中的自定义属性注入到某个Bean对象的多个对应属性中去。

说明：@ConfigurationProperties(prefix = "servers")：将以servers开头的属性注入到Bean对象的对应属性

springboot启动类

package com.gg;

import com.gg.config.ServerConfig;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class Springboot02UseConfigApplication {

    public static void main(String[] args) {
        //  获取容器对象
        ConfigurableApplicationContext context = SpringApplication.run(Springboot02UseConfigApplication.class, args);
        //  从容器中获得Bean对象
        ServerConfig bean = context.getBean(ServerConfig.class);
        System.out.println(bean);
    }

}

运行结果

二、第三方Bean属性绑定

application.yml配置文件

servers:
  ipAddress: 127.0.0.1
  port: 1234
  timeout: -1

datasource:
  driver-class-name: com.mysql.jdbc.Driver1111

启动类

package com.gg;

import com.alibaba.druid.pool.DruidDataSource;
import com.gg.config.ServerConfig;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class Springboot02UseConfigApplication {
    
    @Bean
    @ConfigurationProperties(prefix = "datasource")
    public DruidDataSource druidDataSource(){
        DruidDataSource druidDataSource = new DruidDataSource();
        return druidDataSource;
    }


    public static void main(String[] args) {
        //  获取容器对象
        ConfigurableApplicationContext context = SpringApplication.run(Springboot02UseConfigApplication.class, args);
        //  从容器中获得Bean对象
        ServerConfig bean = context.getBean(ServerConfig.class);
        System.out.println(bean);
        DruidDataSource source = context.getBean(DruidDataSource.class);
        System.out.println(source.getDriverClassName());
    }

}

测试结果

 三、松散绑定

@ConfigurationProperties：支持松散绑定

 @Value：不支持松散绑定

配置文件中对应的属性必须和@Value的属性相同

测试：

配置文件中属性

测试类中的的代码 

 测试结果

改变以下配置文件中的书写格式其他代码不变

执行结果：执行失败

四、常用计量单位

JDK8提供的时间和空间计量单位

1、简单介绍

实体类

package com.gg.config;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import org.springframework.util.unit.DataSize;

import java.time.Duration;

/**
 * @Author: {LZG}
 * @ClassName: ServerConfig
 * @Description: TODO
 * @Date: 2022/4/21 22:59
 **/
@Component
@Data
@ConfigurationProperties(prefix = "servers")
public class ServerConfig {
    private String ipAddress;
    private int port;
    private long timeout;

    private Duration serverTimeOut;

    private DataSize dataSize;

}

配置文件

servers:
  ipAddress: 127.0.0.1
  port: 1234
  timeout: -1
  serverTimeOut: 3
  dataSize: 10
datasource:
  driverClassName: com.mysql.jdbc.Driver1111

执行结果

默认单位是：秒

默认单位：Byte

 2、使用注解设置单位

 此时实体类

package com.gg.config;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.convert.DataSizeUnit;
import org.springframework.boot.convert.DurationUnit;
import org.springframework.stereotype.Component;
import org.springframework.util.unit.DataSize;
import org.springframework.util.unit.DataUnit;

import java.time.Duration;
import java.time.temporal.ChronoUnit;

/**
 * @Author: {LZG}
 * @ClassName: ServerConfig
 * @Description: TODO
 * @Date: 2022/4/21 22:59
 **/
@Component
@Data
@ConfigurationProperties(prefix = "servers")
public class ServerConfig {
    private String ipAddress;
    private int port;
    private long timeout;
    @DurationUnit(ChronoUnit.HOURS)
    private Duration serverTimeOut;
    @DataSizeUnit(DataUnit.MEGABYTES)
    private DataSize dataSize;

}

执行结果

 

 五、数据校验

 开启数据校验功能有助于系统安全性，J2EE规范中JSR303规定了一组有关数据校验的API

 使用JSR303需要导入坐标依赖

       javax.validation
       validation-api


       org.hibernate.validator
       hibernate-validator
       6.2.0.Final

配置文件属性

实体类

package com.gg.config;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.convert.DataSizeUnit;
import org.springframework.boot.convert.DurationUnit;
import org.springframework.stereotype.Component;
import org.springframework.util.unit.DataSize;
import org.springframework.util.unit.DataUnit;
import org.springframework.validation.annotation.Validated;

import javax.validation.constraints.Max;
import java.time.Duration;
import java.time.temporal.ChronoUnit;

/**
 * @Author: {LZG}
 * @ClassName: ServerConfig
 * @Description: TODO
 * @Date: 2022/4/21 22:59
 **/
@Component
@Data
@ConfigurationProperties(prefix = "servers")
// 开启对于当前bean的属性注入校验
@Validated
public class ServerConfig {
    private String ipAddress;
    @Max(value = 8888,message = "最大值不能超过8888")
    private int port;
    private long timeout;
    @DurationUnit(ChronoUnit.HOURS)
    private Duration serverTimeOut;
    @DataSizeUnit(DataUnit.MEGABYTES)
    private DataSize dataSize;

}

 测试结果

 说明：@Validated引入Spring框架支持的数据校验规则

相关的校验规则如下：