Spring Boot @ConfigurationProperties实例(十四)

淡淡的烟草味﹌ 2022-05-16 01:36 138阅读 0赞

> 这篇博文主要用于新手学习Spring Boot，同时也记录自己学习的过程…  
> 文章内容主要来源于[易百教程][Link 1]

Spring Boot `@ConfigurationProperties`是让开发人员比较容易地将整个文件映射成一个对象。  
  
  
**1．简单属性文件**

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

通常，我们使用`@Value`注释来逐个逐入`.properties`值，这对于小而简单的结构`.properties`文件很有用。  
*文件：global.properties*

email=test@th.com
    threadPool=12

@Value示例  
文件：GlobalProperties.java

package com.th;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.PropertySource;
    import org.springframework.stereotype.Component;
    
    @Component
    @PropertySource("classpath:global.properties")
    public class GlobalProperties { 
    
        @Value("${threadPool}")
        private int threadPoll;
    
        @Value("${email}")
        private String email;
    
        public int getThreadPoll() {
            return threadPoll;
        }
    
        public void setThreadPoll(int threadPoll) {
            this.threadPoll = threadPoll;
        }
    
        public String getEmail() {
            return email;
        }
    
        public void setEmail(String email) {
            this.email = email;
        }
    
        @Override
        public String toString() {
            return "GlobalProperties [threadPoll=" + threadPoll + ", email=" + email + "]";
        }
    
    }

@ConfigurationProperties示例  
*文件：GlobalProperties.java*

import org.springframework.boot.context.properties.ConfigurationProperties;
    
    @Component
    @PropertySource("classpath:global.properties")
    @ConfigurationProperties
    public class GlobalProperties { 
    
        private int threadPool;
        private String email;
    
        public int getThreadPool() {
            return threadPool;
        }
        public void setThreadPool(int threadPool) {
            this.threadPool = threadPool;
        }
        public String getEmail() {
            return email;
        }
        public void setEmail(String email) {
            this.email = email;
        }
        @Override
        public String toString() {
            return "GlobalConfigProperties [threadPool=" + threadPool + ", email=" + email + "]";
        }
    
    }

**2．复杂属性文件**

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

2.1．查看复杂的结构 `.properties`文件，如何通过`@Value`注释映射值。  
*文件：application.properties*

spring.mvc.view.prefix=/WEB-INF/jsp/
    spring.mvc.view.suffix=.jsp
    
    #Logging
    logging.level.org.springframework.web=ERROR
    logging.level.com.yiibai=DEBUG
    
    #Global
    email=test@th.com
    threadPool=10
    
    #App
    app.menus[0].title=Home
    app.menus[0].name=Home
    app.menus[0].path=/
    app.menus[1].title=Login
    app.menus[1].name=Login
    app.menus[1].path=/login
    
    app.compiler.timeout=5
    app.compiler.output-folder=/temp/s
    
    app.error=/error/

或YAML中的下面配置，*文件:application.yml*

logging:
      level:
        org.springframework.web: ERROR
        com.th: DEBUG
    email: test@th.com
    threadPool: 10
    app:
      menus:
        - title: Home
          name: Home
          path: /
        - title: Login
          name: Login
          path: /login
      compiler:
        timeout: 5
        output-folder: /temp/
      error: /error/

注意：`@ConfigurationProperties`支持`.properties`和`.yml`文件。

下面可使用`@ConfigurationProperties`来配置完成，创建一个`@ConfigurationProperties bean`，如下所示：  
*文件：AppProperties.java*

package com.th;
    
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.stereotype.Component;
    
    import java.util.ArrayList;
    import java.util.List;
    
    @Component
    @ConfigurationProperties("app")
    public class AppProperties { 
    
        private String error;
        private List<Menu> menus = new ArrayList<>();
        private Compiler compiler = new Compiler();
    
        public static class Menu { 
            private String name;
            private String path;
            private String title;
    
            public String getName() {
                return name;
            }
    
            public void setName(String name) {
                this.name = name;
            }
    
            public String getPath() {
                return path;
            }
    
            public void setPath(String path) {
                this.path = path;
            }
    
            public String getTitle() {
                return title;
            }
    
            public void setTitle(String title) {
                this.title = title;
            }
    
            @Override
            public String toString() {
                return "Menu{" + "name='" + name + '\'' + ", path='" + path + '\'' + ", title='" + title + '\'' + '}';
            }
        }
    
        public static class Compiler { 
            private String timeout;
            private String outputFolder;
    
            public String getTimeout() {
                return timeout;
            }
    
            public void setTimeout(String timeout) {
                this.timeout = timeout;
            }
    
            public String getOutputFolder() {
                return outputFolder;
            }
    
            public void setOutputFolder(String outputFolder) {
                this.outputFolder = outputFolder;
            }
    
            @Override
            public String toString() {
                return "Compiler{" + "timeout='" + timeout + '\'' + ", outputFolder='" + outputFolder + '\'' + '}';
            }
        }
    
        public String getError() {
            return error;
        }
    
        public void setError(String error) {
            this.error = error;
        }
    
        public List<Menu> getMenus() {
            return menus;
        }
    
        public void setMenus(List<Menu> menus) {
            this.menus = menus;
        }
    
        public Compiler getCompiler() {
            return compiler;
        }
    
        public void setCompiler(Compiler compiler) {
            this.compiler = compiler;
        }
    
        @Override
        public String toString() {
            return "AppProperties [error=" + error + ", menus=" + menus + ", compiler=" + compiler + "]";
        }
    
    }

*文件：GlobalProperties.java*

package com.th;
    
    import javax.validation.constraints.Max;
    import javax.validation.constraints.Min;
    import javax.validation.constraints.NotEmpty;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.stereotype.Component;
    
    @Component
    @ConfigurationProperties
    public class GlobalProperties { 
    
        @Max(20)
        @Min(0)
        @Value("${threadPool}")
        private int threadPoll;
    
        @NotEmpty
        @Value("${email}")
        private String email;
    
        public int getThreadPoll() {
            return threadPoll;
        }
    
        public void setThreadPoll(int threadPoll) {
            this.threadPoll = threadPoll;
        }
    
        public String getEmail() {
            return email;
        }
    
        public void setEmail(String email) {
            this.email = email;
        }
    
        @Override
        public String toString() {
            return "GlobalProperties [threadPoll=" + threadPoll + ", email=" + email + "]";
        }
    
    }

**演示实例**

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

测试以确保 `.properties`值正确映射到对象。文件：*WelcomController.java* \-  
package com.th;

import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import java.util.Map;
    
    @Controller
    public class WelcomeController { 
        private static final Logger logger = LoggerFactory.getLogger(WelcomeController.class);
    
        private AppProperties app;
        private GlobalProperties global;
    
        @Autowired
        public void setApp(AppProperties app) {
            this.app = app;
        }
    
        @Autowired
        public void setGlobal(GlobalProperties global) {
            this.global = global;
        }
    
        @RequestMapping("/")
        public String welcome(Map<String, Object> model) {
    
            String appProperties = app.toString();
            String globalProperties = global.toString();
    
            logger.debug("Welcome {}, {}", app, global);
    
    
            model.put("message", appProperties + globalProperties);
            return "welcom";
        }
    
    
    }

*文件：SpringBootWebApplication.java*

package com.th;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    public class SpringBootWebApplication { 
    
        public static void main(String[] args) {
            SpringApplication.run(SpringBootWebApplication.class, args);
        }
    }

使用Maven命令 `mvn spring-boot:run` 启动Spring Boot，打开浏览器访问[http://localhost:8080][http_localhost_8080]  
![这里写图片描述][20180810114226366]

**相关文章：**

*  [Spring Boot教程(一)][Spring Boot]
 *  [Spring Boot是什么？(二)][Spring Boot 1]
 *  [Spring Boot主要目标(三)][Spring Boot 2]
 *  [新项目为什么需要Spring Boot？(四)][Spring Boot 3]
 *  [Spring Boot核心和限制(五)][Spring Boot 4]
 *  [Spring Boot优点和缺点(六)][Spring Boot 5]
 *  [Spring Boot入门(七)][Spring Boot 6]
 *  [Spring Boot安装(八)][Spring Boot 7]
 *  [Spring Boot应用程序开发入门(九)][Spring Boot 8]
 *  [Spring Boot JSP应用实例(十)][Spring Boot JSP]
 *  [Spring Boot将WAR文件部署到Tomcat(十一)][Spring Boot_WAR_Tomcat]
 *  [Spring Boot Hello World(Thymeleaf)示例(十二)][Spring Boot Hello World_Thymeleaf]
 *  [Spring Boot非web应用程序实例(十三)][Spring Boot_web]
 *  [Spring Boot SLF4J日志实例(十五)][Spring Boot SLF4J]
 *  [Spring Boot Ajax实例(十六)][Spring Boot Ajax]

[Link 1]: https://www.yiibai.com/spring-boot/
[http_localhost_8080]: http://localhost:8080
[20180810114226366]: /images/20220516/66030de176ba42cdbd577ade344e7908.png
[Spring Boot]: https://blog.csdn.net/ththcc/article/details/81631532
[Spring Boot 1]: https://blog.csdn.net/ththcc/article/details/81632203
[Spring Boot 2]: https://blog.csdn.net/ththcc/article/details/81632326
[Spring Boot 3]: https://blog.csdn.net/ththcc/article/details/81632670
[Spring Boot 4]: https://blog.csdn.net/ththcc/article/details/81632792
[Spring Boot 5]: https://blog.csdn.net/ththcc/article/details/81632923
[Spring Boot 6]: https://blog.csdn.net/ththcc/article/details/81632964
[Spring Boot 7]: https://blog.csdn.net/ththcc/article/details/81633063
[Spring Boot 8]: https://blog.csdn.net/ththcc/article/details/81660779
[Spring Boot JSP]: https://blog.csdn.net/ththcc/article/details/81660830
[Spring Boot_WAR_Tomcat]: https://blog.csdn.net/ththcc/article/details/81660865
[Spring Boot Hello World_Thymeleaf]: https://blog.csdn.net/ththcc/article/details/81660896
[Spring Boot_web]: https://blog.csdn.net/ththcc/article/details/81660975
[Spring Boot SLF4J]: https://blog.csdn.net/ththcc/article/details/81661266
[Spring Boot Ajax]: https://blog.csdn.net/ththcc/article/details/81870702