Springboot使用-静态类读取配置文件

「爱情、让人受尽委屈。」 2023-02-12 05:47 12阅读 0赞

### 文章目录 ###

*  1 springboot读取配置文件的两种方式
 *  2 静态类读取配置文件

# 1 springboot读取配置文件的两种方式 #

属性上使用：@Value("${xxxx}")
    类上使用：@ConfigurationProperties(prefix = "xxx")

# 2 静态类读取配置文件 #

思路

1 工具类增加静态属性的初始化方法init
    2 创建bean对象
        - 通过@ConfigurationProperties读取配置文件
        - 通过component将bean对象注入到容器中
    3 创建代理类
        - 通过component读取容器中bean对象的属性
        - 在构造方法中调用工具类静态属性的初始化方法init，从而初始化工具类的静态属性

*  1 创建maven项目GetProperties
 *  2 修改pom.xml，引入parent/web/test依赖

<parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.3.0.RELEASE</version>
        </parent>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
            </dependency>
        </dependencies>

*  3 增加配置文件/resources/application.properties,内容为

study.theme=getProperties
    study.result=true

*  4 增加启动类cn.ithzp.properties.PropertiesApplication

package cn.ithzp.properties;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    public class PropertiesApplication {
        public static void main(String[] args) {
            SpringApplication.run(PropertiesApplication.class);
        }
    }

*  5 核心三部曲，工具类增加静态变量初始化方法init

package cn.ithzp.properties.util;
    
    import cn.ithzp.properties.entity.StudyEntity;
    
    public class StudyUtil {
        private static String theme;
        private static String result;
        public static void initStaticProperties(StudyEntity studyEntity){
            theme = studyEntity.getTheme();
            result = studyEntity.getResult();
        }
        
        public static String getStaticProperties() {
            return theme + ":" + result;
        }
    }

*  6 核心三部曲,具体bean对象读取配置文件

package cn.ithzp.properties.entity;
    
    import lombok.Data;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.stereotype.Component;
    
    @Data
    @Component
    @ConfigurationProperties(prefix = "study")
    public class StudyEntity {
        private String theme;
        private String result;
    }

*  7 核心三部曲，代理类构造方法中调用工具类静态属性的初始化方法

package cn.ithzp.properties.Proxy;
    
    import cn.ithzp.properties.entity.StudyEntity;
    import cn.ithzp.properties.util.StudyUtil;
    import org.springframework.stereotype.Component;
    
    @Component
    public class StudyProxy {
        public StudyProxy(StudyEntity studyEntity) {
            StudyUtil.initStaticProperties(studyEntity);
        }
    }

*  8 增加测试类,测试验证

package cn.ithzp.properties;
    
    import cn.ithzp.properties.entity.StudyEntity;
    import cn.ithzp.properties.util.StudyUtil;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    
    @SpringBootTest(classes = {PropertiesApplication.class})
    @RunWith(SpringRunner.class)
    public class TestApplication {
        @Autowired
        private StudyEntity studyEntity;
    
        @Test
        public void test() {
            System.out.println(studyEntity);
            System.out.println(StudyUtil.getStaticProperties());
        }
    }