java - Spring Boot 应用程序 : Could not resolve placeholder in application. 属性？

Question

我有一个 Spring Boot 应用程序。当我单击 SpringToolSuit4 中的“运行”按钮时，它可以正常工作。

但是当我以“maven install”运行时，我收到了错误消息:

<error message="Failed to load ApplicationContext" type="java.lang.IllegalStateException">java.lang.IllegalStateException: Failed to load ApplicationContext
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeController': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'envVersionNum' in value "${envVersionNum}"
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'envVersionNum' in value "${envVersionNum}"
</error>

我的应用程序属性的内容:

spring.h2.console.enabled=true
spring.h2.console.path=/h2-console
spring.jpa.show-sql=true
spring.thymeleaf.cache=false
version=${envVersionNum}

如果我把它改成

spring.h2.console.enabled=true
spring.h2.console.path=/h2-console
spring.jpa.show-sql=true
spring.thymeleaf.cache=false
version=1.1.1

它工作正常。但我想从用户那里获取 envVersionNum，它存储在 .bash_profile (export envVersionNum= 1.1.1) 中。

pom.xml 的内容:

    <?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>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.jrp</groupId>
    <artifactId>project-management</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>project-management</name>
    <description>project management application</description>

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

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </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>

homeController的代码:

package com.jrp.pma.controllers;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.jrp.pma.dao.EmployeeRepository;
import com.jrp.pma.dao.ProjectRepository;
import com.jrp.pma.dto.ChartData;
import com.jrp.pma.dto.EmployeeProject;
import com.jrp.pma.entities.Project;

@Controller
public class HomeController {

    @Value("${version}")
    private String ver;

    @Autowired
    ProjectRepository proRepo;

    @Autowired
    EmployeeRepository empRepo;

    @GetMapping("/")
    public String displayHome(Model model) throws JsonProcessingException {

        model.addAttribute("versionNumber", ver);

        Map<String, Object> map = new HashMap<>();

        // we are querying the database for projects
        List<Project> projects = proRepo.findAll();
        model.addAttribute("projectsList", projects);

        List<ChartData> projectData = proRepo.getProjectStatus();

        // Lets convert projectData object into a json structure for use in javascript
        ObjectMapper objectMapper = new ObjectMapper();
        String jsonString = objectMapper.writeValueAsString(projectData);
        //[["NOTSTARTED", 1], ["INPROGRESS", 2], ["COMPLETED", 1]]
        model.addAttribute("projectStatusCnt", jsonString);

        // we are querying the database for employees
        List<EmployeeProject> employeesProjectCnt = empRepo.employeeProjects();
        model.addAttribute("employeesListProjectsCnt", employeesProjectCnt);

        return "main/home";
    }
}

任何建议都欣然接受。

Answer 1

如果您在导出命令中设置任何环境变量，那么它只能通过命令行才能看到。

如果您使用的是 Eclipse 或任何其他 IDE，则它不会从导出命令中获取值，因为导出的范围在终端内。

尝试在命令行中导出变量后运行您的 jar，它将起作用。