Spring Boot整合PostgreSQL报错：无法解析PostgreSQL9Dialect

我用Spring Boot搭建PostgreSQL API时碰到了问题，之前搭过好几次同类项目，对比旧项目发现这次操作没太大区别，只是实体类和关联关系不一样。试了加不同依赖，问题还是没解决。

报错信息 #

2024-02-19T17:07:52.151Z WARN 2851 --- [ restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment] due to: Unable to resolve name [org.hibernate.dialect.PostgreSQL9Dialect] as strategy [org.hibernate.dialect.Dialect]

项目配置文件 #

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>3.2.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>Back.end</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Text based adventure</description>
    <properties>
        <java.version>17</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.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </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>

DataLoader代码 #

package Back.end.demo.Components;

import Back.end.demo.Adventurer;
import Back.end.demo.Enemy;
import Back.end.demo.Location;
import Back.end.demo.Repositories.AdventurerRepository;
import Back.end.demo.Repositories.EnemyRepository;
import Back.end.demo.Repositories.TreasureRepository;
import Back.end.demo.Treasure;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.context.annotation.Profile;
import org.springframework.stereotype.Component;

@Profile("!test")
@Component
public class DataLoader implements ApplicationRunner {

    @Autowired
    AdventurerRepository adventurerRepository;

    @Autowired
    EnemyRepository enemyRepository;

    @Autowired
    TreasureRepository treasureRepository;

    public DataLoader() {

    }

    public void run(ApplicationArguments args){
        Adventurer mcfee = new Adventurer("McFee", 0, Location.TOWN, "Fists", 0, true);
        this.adventurerRepository.save(mcfee);

        Adventurer mjohnson = new Adventurer("Mary Johnson", 50, Location.GARDEN, "Longsword", 1, true);
        this.adventurerRepository.save(mjohnson);

        Adventurer raj = new Adventurer("Raj", 0, Location.FOREST, "Dagger", 0, true);
        this.adventurerRepository.save(raj);

        Adventurer greg = new Adventurer("Greg", 500, Location.CASTLE, "Battle Axe", 3, true);
        this.adventurerRepository.save(greg);

        Enemy goblin = new Enemy("Goblin", "Dagger", false, Location.GARDEN);
        this.enemyRepository.save(goblin);

        Enemy knight = new Enemy("Undead Knight", "Greatsword", false, Location.CASTLE);
        this.enemyRepository.save(knight);

        Enemy troll = new Enemy("Troll", "Club", false, Location.FOREST);
        this.enemyRepository.save(troll);

        Enemy jester = new Enemy("Jingle the Jester", null, false, Location.GARDEN);
        this.enemyRepository.save(jester);

        Treasure diamond = new Treasure("Diamond", 1000, null, Location.CASTLE);
        this.treasureRepository.save(diamond);

        Treasure sapphire = new Treasure("Sapphire", 500, null, Location.CASTLE);
        this.treasureRepository.save(sapphire);

        Treasure emerald = new Treasure("Emerald", 350, null, Location.GARDEN);
        this.treasureRepository.save(emerald);

        Treasure ruby = new Treasure("Ruby", 350, null, Location.GARDEN);
        this.treasureRepository.save(ruby);

        Treasure sandals = new Treasure("Winged Sandals of Hermes", 1000, null, Location.CASTLE);
        this.treasureRepository.save(sandals);

        Treasure coin = new Treasure("Gold Coin", 50, null, Location.FOREST);
        this.treasureRepository.save(coin);

        Treasure blackRuby = new Treasure("Black Ruby of Voldesadt", 1500, null, Location.CASTLE);
        this.treasureRepository.save(blackRuby);
    }
}

application.properties #

spring.datasource.url=jdbc:postgresql://localhost:5432/adventurers
spring.datasource.username=postgres
spring.datasource.password=postgres
spring.jpa.hibernate.ddl-auto=update
spring.jpa.database-platform=org.hibernate.dialect.PostgreSQL9Dialect
spring.jpa.properties.hibernate.enable_lazy_load_no_trans=true

问题原因 #

Spring Boot 3.2.2依赖的Hibernate版本是6.x，而org.hibernate.dialect.PostgreSQL9Dialect在Hibernate 6.x中已被移除，替换为了新的方言类。

解决步骤 #

修改application.properties中的方言配置，任选以下一种方式：

1. 使用通用PostgreSQL方言（推荐，Hibernate会自动适配对应数据库版本）：

spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect

2. 指定对应版本的方言（例如PostgreSQL 10+版本）：

spring.jpa.database-platform=org.hibernate.dialect.PostgreSQL10Dialect

另外，Spring Boot检测到PostgreSQL数据源时会自动配置正确的方言，你也可以直接删除spring.jpa.database-platform这一行，让框架自动处理。

内容的提问来源于stack exchange，提问作者Ewan Gomolka