聊聊@value注解和@ConfigurationProperties注解的使用聊聊@value注解和@ConfigurationPr

@value注解和@ConfigurationProperties注解

@value读取默认配置
@ConfigurationProperties读取默认配置

@ConfigurationProperties和@Value使用上的一点区别

第一段代码
第二段代码

@value注解和@ConfigurationProperties注解
@value读取默认配置
yml文件内容如下（装了STS插件以后即可直接使用，改后缀就行了）

user:username: xiongdasex: manage: 20school:name: xtulocation: hunan

备注：一定要注意之间要留空格，发现颜色变绿色了才是正确的格式，这个坑我刚踩

package com.example.demo.service.impl; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Service; import com.example.demo.service.ReadConfigService; @Servicepublic class ReadConfigServiceImpl implements ReadConfigService {@Value(value="https://www.it610.com/article/${user.username}")private String username; @Value(value="https://www.it610.com/article/${user.sex}")private String sex; @Value(value="https://www.it610.com/article/${user.age}")private String age; @Value(value="https://www.it610.com/article/${school.name}")private String name; @Value(value="https://www.it610.com/article/${school.location}")private String location; @Overridepublic String getUserMessage() {return "user ="+username+" sex ="+sex+" age="+age; } @Overridepublic String getAuthorMessage() {return "schoolname="+name+"location="+location; }}

@ConfigurationProperties读取默认配置

package com.example.demo.config; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.stereotype.Component; @Component@ConfigurationProperties(prefix="user")public class HelloConfig {private String username; private String sex; private String age; public String getUsername() {return username; } public void setUsername(String username) {this.username = username; } public String getSex() {return sex; } public void setSex(String sex) {this.sex = sex; } public String getAge() {return age; } public void setAge(String age) {this.age = age; }}

【聊聊@value注解和@ConfigurationProperties注解的使用】调用的controller层

package com.example.demo.web; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import com.example.demo.config.HelloConfig; import com.example.demo.service.ReadConfigService; @RestController@RequestMapping("hello")public class HelloController {@AutowiredReadConfigService readConfigService; @AutowiredHelloConfig helloConfig; @RequestMapping("/user")public String say() {return "username "+helloConfig.getUsername()+" sex "+helloConfig.getSex()+" age "+helloConfig.getAge(); }@RequestMapping("/school")public String school() {return readConfigService.getAuthorMessage(); }}

@ConfigurationProperties和@Value使用上的一点区别 @ConfigurationProperties和@Value的一个共同点就是从配置文件中读取配置项。
发现有一点区别，我项目配置中并没有配置hello.msg ，当使用第一段代码时，启动后读取到msg为null，而第二段代码则会抛出异常。
第二段代码有个好处，就是防止我们配置项遗漏，当遗漏时，启动程序肯定出错，这样避免了一些因为遗漏配置项导致的BUG.

第一段代码

import org.springframework.boot.context.properties.ConfigurationProperties; @ConfigurationProperties("hello")public class HelloProperties {private String msg; public String getMsg() {return msg; }public void setMsg(String msg) {this.msg = msg; }}

第二段代码

import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Component; @Componentpublic class Hello2Properties {@Value("${hello.msg}")private String msg; public String getMsg() {return msg; }public void setMsg(String msg) {this.msg = msg; }}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。