未读取外部 Spring 引导属性

Question

我使用的是 spring boot 2.2.2 并且我有一些我想从属性文件中读取的外部属性。 当属性是默认 application.properties 的一部分时，所有属性都会被读取，但是当我将其移动到单独的属性文件时，它们似乎没有被读取。

我有以下课程：

@Getter
@ConfigurationProperties  //I use @ConfigurationPropertiesScan with @SpringBootApplication
@PropertySource(value = "classpath:myprops.properties")
public class MyProperties {

    private final String prop1;
    private final Integer prop2;
    private final String prop3;

    @ConstructorBinding
    public MyProperties (String prop1, Integer prop2, String prop3) {
        this.prop1= prop1;
        this.prop2= prop2;
        this.prop3= prop3;
    }
}

所以 prop1、prop2 和 prop3 在 application.properties 中时获得它们的值（当然也省略了 @PropertySource 注释），但是当我将它移动到资源下的 myprops.properties 时，我看到 prop1、prop2 和 prop3 为 null写在上面

Answer 1

尝试创建带有@Configuration 注释的类，就像在docs 中一样

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;

@Configuration
@PropertySource(value = "classpath:myprops.properties")
public class MyConfiguration {
}

从MyProperties 类中删除@PropertySource 并将其放在MyConfiguration 中。

更新：

使其工作的步骤：

1) 转到https://start.spring.io。生成项目并添加：Spring Configuration Processor 和 Lombok（启用注释处理）

2) 添加或检查：

• myprops.properties 到资源（在 application.properties 旁边）
• MyConfiguration 和 MyProperties 旁边有 main 方法的类

package com.example.demostackannotations;

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;

@Configuration
@PropertySource(value = "classpath:myprops.properties")
public class MyConfiguration {
}

package com.example.demostackannotations;

import lombok.Getter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.ConstructorBinding;

@Getter
@ConfigurationProperties
public class MyProperties {

    private final String prop1;
    private final Integer prop2;
    private final String prop3;

    @ConstructorBinding
    public MyProperties(String prop1,  Integer prop2,  String prop3) {
        this.prop1 = prop1;
        this.prop2 = prop2;
        this.prop3 = prop3;
    }
}

• @ConfigurationPropertiesScan 到带有 main 方法的类

@SpringBootApplication
@ConfigurationPropertiesScan
public class DemoStackAnnotationsApplication {

    public static void main(String[] args) {
        ApplicationContext app = SpringApplication.run(DemoStackAnnotationsApplication.class, args);
        MyProperties props = app.getBean(MyProperties.class);
        System.out.println(props.getProp1());
        System.out.println(props.getProp2());
        System.out.println(props.getProp3());
    }
}

• pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo-stack-annotations</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo-stack-annotations</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>