Heroku Postgres与Spring启动JPA无法正常工作

Question

我正在学习如何在我的heroku免费帐户上部署一个spring boot应用程序。一切顺利，直到我想使用真正的Postgres数据库提供作为Heroku的可能附加组件之一。我添加了我的附加组件，并且我能够获得连接到DB的所有设置，但是当我创建JpaRepositories并将Pojos映射到db时，它无法创建数据库。

我的Heroku仪表板为我提供了访问数据库的所有凭据，我在Spring启动应用程序中使用它们，即使Heroku会定期更改它们使用环境变量覆盖它们。

这里是application.properties：

spring.jpa.hibernate.ddl-auto=create-drop
spring.datasource.url=jdbc:postgres://xxxxxxxx:xxxxxx
spring.datasource.username=xxxxxxxx
spring.datasource.password=xxxxxxxx

即使我已经读过Heroku将使用环境变量覆盖数据源数据。

这是我的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>com.quicktutorialz.learnmicroservices</groupId>
<artifactId>DemoHeroku</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>DemoHeroku</name>
<description>Demo project for Spring Boot</description>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.9.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-data-jpa</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>
        <optional>true</optional>
        <version>1.16.10</version> <!-- added -->
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

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

这是我的控制器：

package com.quicktutorialz.learnmicroservices.DemoHeroku;

import com.quicktutorialz.learnmicroservices.DemoHeroku.daos.AuthorDao;
import com.quicktutorialz.learnmicroservices.DemoHeroku.daos.BookDao;
import com.quicktutorialz.learnmicroservices.DemoHeroku.entities.Author;
import com.quicktutorialz.learnmicroservices.DemoHeroku.entities.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.PostConstruct;
import javax.validation.Valid;
import java.util.List;

@RestController
@SpringBootApplication
public class DemoHerokuApplication {

public static void main(String[] args) {
    SpringApplication.run(DemoHerokuApplication.class, args);
}

@Autowired AuthorDao authorDao;
@Autowired BookDao bookDao;

@RequestMapping("/")
public String hello(){
    return "Hello!";
}

@RequestMapping("/books")
public List<Book> getBooks(){
    return bookDao.findAll();
}

@RequestMapping("/books/{id}")
public Book getOneBook(@PathVariable(name = "id") Integer id){
    return bookDao.findOne(id);
}

@RequestMapping("/authors")
public List<Author> getAuthors(){
    return authorDao.findAll();
}

@RequestMapping("/authors/{id}")
public Author getOneAuthor(@PathVariable(name = "id") Integer id){
    return authorDao.findOne(id);
}

@RequestMapping("/books/save")
public Book saveBook(@Valid Book book){
    return bookDao.save(book);
}

@RequestMapping("/books/delete/{id}")
public List<Book> deleteBook(@PathVariable(name = "id") Integer id){
    bookDao.delete(id);
    return bookDao.findAll();
}

@RequestMapping("/authors/save")
public Author saveAuthor(@Valid Author author){
    return authorDao.save(author);
}

@RequestMapping("/authors/delete/{id}")
public List<Author> deleteAuthor(@PathVariable(name = "id") Integer id){
    authorDao.delete(id);
    return authorDao.findAll();
}

@PostConstruct
private void fillDatabase(){
    authorDao.save(new Author(null, "Gino Camarda", "[email protected]"));
    authorDao.save(new Author(null, "Attilia Nomeldini", "[email protected]"));

    bookDao.save(new Book(null, "Il basket per me", "Saggio sportivo", null, 1));
    bookDao.save(new Book(null, "W il basket", "Saggio sportivo", null, 1));

    bookDao.save(new Book(null, "Giornali e pareri", "Saggio giornalistico", null, 2));
    bookDao.save(new Book(null, "Versioni della verita", "Saggio giornalistico", null, 2));

}
}

这是我的第一个POJO：

package com.quicktutorialz.learnmicroservices.DemoHeroku.entities;

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.hibernate.validator.constraints.NotBlank;

import javax.persistence.*;

@Entity @Table(name="authors") @AllArgsConstructor @NoArgsConstructor 
@Getter @Setter
public class Author {

  @Id @Column(name="ID") @GeneratedValue
  private Integer id;
  @Column(name="NAME") @NotBlank
  private String name;
  @Column(name="EMAIL") @NotBlank
  private String email;
}

这是我的第二个POJO：

package com.quicktutorialz.learnmicroservices.DemoHeroku.entities;

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.hibernate.validator.constraints.NotBlank;

import javax.persistence.*;
import javax.validation.constraints.NotNull;
import java.util.Date;

@Entity @Table(name="books")
@AllArgsConstructor @NoArgsConstructor @Getter @Setter
public class Book {
  @Id @Column(name="ID") @GeneratedValue
  private Integer id;
  @Column(name="TITLE") @NotBlank
  private String title;
  @Column(name="TITLE") @NotBlank
  private String description;
  @Column(name="TITLE")
  private Date dateOfRelease;
  @Column(name="TITLE") @NotNull
  private int authorId;

  @PrePersist
  private void setDate(){
    this.dateOfRelease = new Date();
  }
}

这些是JpaRepositories。

author DAO.Java:

package com.quicktutorialz.learnmicroservices.DemoHeroku.daos;

import com.quicktutorialz.learnmicroservices.DemoHeroku.entities.Author;
import org.springframework.data.jpa.repository.JpaRepository;

public interface AuthorDao extends JpaRepository<Author, Integer>{

}

book DAO.Java

package com.quicktutorialz.learnmicroservices.DemoHeroku.daos;

import com.quicktutorialz.learnmicroservices.DemoHeroku.entities.Book;
import org.springframework.data.jpa.repository.JpaRepository;

public interface BookDao extends JpaRepository<Book, Integer>{
}

当我尝试在本地使用Maven打包它时，我收到此错误：

Description:

Cannot determine embedded database driver class for database type NONE

当我在Heroku上部署时，我的应用程序因一般错误而崩溃：

at=error code=H10 desc="App crashed" method=GET path="/"

Answer 1

问题是由于Book pojo中注释@Column的复制过去。有完全相同名称的列！