在我们编写Spring Boot项目的时候，需要对一些值进行配置。但是有的时候我们不知道默认的属性有哪些(出了常用的)，我们可以根据自己的需要进行自定义属性,
也可以根据不同的环境指定不同的配置文件。
自定义属性
需要将自定义的属性写入到src/main/resources/application.yml文件中，内容如下:
## Top level app properties
app:
name: ConfigurationPropertiesDemoApp
description: ${app.name} is a spring boot app that demonstrates how to use external configuration properties
upload-dir: /uploads
connect-timeout: 500ms
read-timeout: 10s
security:
username: admin
password: 123456
roles: USER,ADMIN,PARTNER # List Property
enabled: true
## Map Properties (permissions)
permissions:
CAN_VIEW_POSTS: true
CAN_EDIT_POSTS: true
CAN_DELETE_POSTS: false
CAN_VIEW_USERS: true
CAN_EDIT_USERS: true
CAN_DELETE_USERS: false
将属性与类进行绑定
如果想要将外部的属性与类类进行绑定，需要在类里面添加@ConfigurationProperties注解,并且指定前缀。绑定类的代码如下:
package com.edu.springboot.configurepropertiesdemo.config;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.convert.DurationUnit;
import java.time.Duration;
import java.time.temporal.ChronoUnit;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@ConfigurationProperties(prefix = "app")
public class AppProperties {
private String name;
private String description;
private String uploadDir;
private Duration connectTimeout = Duration.ofMillis(1000);
@DurationUnit(ChronoUnit.SECONDS)
private Duration readTimeout = Duration.ofSeconds(30);
private final Security security = new Security();
//省略get/set方法
public static class Security {
private String username;
private String password;
private List<String> roles = new ArrayList<>();
private boolean enabled;
private Map<String, String> permissions = new HashMap<>();
//省略get/set方法
}
}
数据绑定
- Type-safe binding:如果想要将属性绑定为list(roles)，需要将类型使用逗号分割,permissions使用map来绑定。
- Duration Support:默认的单位为毫秒。
- Naming Convention:在命名的时候使用驼峰法，在转换的时候，可以使用驼峰或者kebab(使用-来连接)。
打开配置属性
在打开配置属性时，需要将添加@EnableConfigurationProperties注解，代码如下:
package com.edu.springboot.configurepropertiesdemo;
import com.edu.springboot.configurepropertiesdemo.config.AppProperties;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
@SpringBootApplication
@EnableConfigurationProperties(AppProperties.class)
public class ConfigurePropertiesDemoApplication {
public static void main(String[] args) {
SpringApplication.run(ConfigurePropertiesDemoApplication.class, args);
}
}
注入配置
package com.edu.springboot.configurepropertiesdemo.controller;
import com.edu.springboot.configurepropertiesdemo.config.AppProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.HashMap;
import java.util.Map;
@RestController
public class IndexController {
@Autowired
private AppProperties appProperties;
@GetMapping("/")
public Map<String, String> getAppDetails() {
Map<String, String> appDetails = new HashMap<>();
appDetails.put("name", appProperties.getName());
appDetails.put("description", appProperties.getDescription());
return appDetails;
}
}
属性验证
可以使用注解方式，来防止某些配置为空，验证某些属性是否符合标准。
package com.edu.springboot.configurepropertiesdemo.config;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.convert.DurationUnit;
import org.springframework.validation.annotation.Validated;
import javax.validation.Valid;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;
import java.time.Duration;
import java.time.temporal.ChronoUnit;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@ConfigurationProperties(prefix = "app")
@Validated
public class AppProperties {
@NotNull
private String name;
private String description;
private String uploadDir;
private Duration connectTimeout = Duration.ofMillis(1000);
@DurationUnit(ChronoUnit.SECONDS)
private Duration readTimeout = Duration.ofSeconds(30);
@Valid
private final Security security = new Security();
//get/set方法省略
public static class Security {
private String username;
private String password;
@NotEmpty
private List<String> roles = new ArrayList<>();
private boolean enabled;
private Map<String, String> permissions = new HashMap<>();
//get/set方法省略
}
}
指定配置文件
在默认情况下，读取application.yml/application.properties文件,Spring Boot项目中也允许根据环境创建相应的配置文件。
application-{profile}.properties
指定的配置文件也要放到src/main/resources文件下。
application-dev.yml
app:
name: ConfigurationPropertiesDemoApp-DEVELOPMENT
security:
username: dev
application-stage.yml
app:
name: ConfigurationPropertiesDemoApp-STAGING
security:
username: stage
password: stage
application-prod.yml
app:
name: ConfigurationPropertiesDemoApp-PRODUCTION
security:
username: prod
password: prod
激活Profile
1.application profiles
spring.profiles.active=staging
2.命令行参数
mvn clean package -Dspring.profiles.active=staging
# Running the packaged jar with `spring.profiles.active` argument
java -jar -Dspring.profiles.active=staging target/config-properties-demo-0.0.1-SNAPSHOT.jar
#或者使用
mvn spring-boot:run -Dspring.profiles.active=dev
3.环境变量
export SPRING_PROFILES_ACTIVE=prod
运行应用程序
#运行
mvn spring-boot:run
#获取数据
curl http://localhost:8080
{"name":"ConfigurationPropertiesDemoApp","description":"ConfigurationPropertiesDemoApp is a spring boot app that demonstrates how to use external configuration
运行特定环境
#指定运行环境
mvn spring-boot:run -Dspring.profiles.active=prod
#运行结果
curl http://localhost:8080
{"name":"ConfigurationPropertiesDemoApp-PRODUCTION","description":"ConfigurationPropertiesDemoApp-PRODUCTION is a spring boot app that demonstrates how to use external configuration properties"}
也可以在pom.xml文件中添加要激活的环境。
代码放在github
参考文献
Spring Boot @ConfigurationProperties: Binding external configurations to POJO classes
Externalized Configuration
常用属性配置列表
