在 Heroku 上设置 PostgreSQL 数据库（需要 entityManagerFactory）

Question

我想在 Spring Boot 中实现的 Heroku 上创建一个 Web 应用程序。最后，我设法部署了一个带有“Whitelabel error page 404”的普通项目，确认了部署的正确性。

我跟着（几乎一样）：https://devcenter-assets0.herokucdn.com/articles/spring-boot-memcache

不幸的是，我在 Spring Data JPA 中只遇到了一个（我希望是）问题（在添加服务（例如 Spring Security 和 Lombok 正常工作）之后），这使我无法构建应用程序和使用 PostgreSQL：

Description:
Parameter 0 of constructor in io.github.plkpiotr.fifabackend.controller.TaskController required a bean named 'entityManagerFactory' that could not be found.

Action:
Consider defining a bean named 'entityManagerFactory' in your configuration.

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>io.github.plkpiotr</groupId>
    <artifactId>fifa-backend</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>fifa-backend</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

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

        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.22</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
        </dependency>

    </dependencies>

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

</project>

application.properties：

spring.datasource.driverClassName=org.postgresql.Driver
spring.datasource.maxActive=10
spring.datasource.maxIdle=5
spring.datasource.minIdle=2
spring.datasource.initialSize=5
spring.datasource.removeAbandoned=true
spring.jpa.properties.hibernate.temp.use_jdbc_metadata_defaults = false
spring.jpa.database-platform=org.hibernate.dialect.PostgreSQL9Dialect
spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration

Task.java：

package io.github.plkpiotr.fifabackend.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.validation.constraints.NotNull;

@Entity
public class Task {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Long id;

    @NotNull
    private String name;

    public Task() {}

    public Task(String name) {
        this.name = name;
    }

    public Long getId() {
        return this.id;
    }

    public String getName() {
        return this.name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return String.format("Task[id=%d, name='%s']", this.id, this.name);
    }

}

TaskRepository.java：

package io.github.plkpiotr.fifabackend.repository;

import io.github.plkpiotr.fifabackend.model.Task;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface TaskRepository extends CrudRepository<Task, Long> {}

TaskController.java：

package io.github.plkpiotr.fifabackend.controller;

import javax.validation.Valid;
import java.lang.Iterable;

import io.github.plkpiotr.fifabackend.model.Task;
import io.github.plkpiotr.fifabackend.repository.TaskRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

@Controller
@RequestMapping("/")
public class TaskController {

    @Autowired
    private TaskRepository taskRepo;

    @Autowired
    public TaskController(TaskRepository repo) {
        this.taskRepo = repo;
    }

    @RequestMapping(method = RequestMethod.GET)
    public String showAllTasks(ModelMap model) {
        Iterable<Task> tasks = this.taskRepo.findAll();
        model.addAttribute("tasks", tasks);
        model.addAttribute("newTask", new Task());
        return "task";
    }

    @RequestMapping(method = RequestMethod.POST)
    public String newTask(ModelMap model,
                          @ModelAttribute("newTask") @Valid Task task,
                          BindingResult result) {
        if (!result.hasErrors()) {
            this.taskRepo.save(task);
        }
        return showAllTasks(model);
    }

    @RequestMapping(method = RequestMethod.DELETE)
    public String deleteTask(ModelMap model, @RequestParam("taskId") Long id) {
        this.taskRepo.deleteById(id);
        return showAllTasks(model);
    }
}

我试过了：

1)。添加差异化依赖项（h2、hibernate-core、...）

2)。删除 /.m2/ 文件夹并重新下载依赖项

3)。不要在其他尝试失败后哭泣...

如果您对克隆回购感兴趣： https://github.com/plkpiotr/fifa-backend

除此之外，如果我在 TaskController.java 中删除，我会得到：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: At least one JPA metamodel must be present!

如何解决问题？

Answer 1

@EntityScan、@EnableJpaRepositories 和 @ComponentScan 不支持通配符语法。例如您当前使用的：

@EntityScan("io.github.plkpiotr.*")`

但它应该只是基本包名

@EntityScan("io.github.plkpiotr")