Question

我有一个Java Web应用程序，我试图通过类配置的Hibernate从Postgres数据库中检索客户端列表。据我所知，应用程序确实获得了连接，因为我检查了连接中的元数据，我看到了所有表格，所以它没问题。问题是我从表中得不到任何数据。

以下是我的客户模型：

@Entity
@Table(name="Client")
public class Client implements Serializable {

    @Id
    @Column(name="id", nullable= false)
    private Integer id;

    @Column(name="age", nullable = false)
    private Integer age;

    @Column(name="numberofrentals", nullable = false)
    private Integer numberofrentals;

    @Column(name="name", nullable = false)
    private String name;

    @Column(name="address", nullable = false)
    private String address;

    public Client() {
    }

    public Client(Integer id, Integer age, Integer numberofrentals, String name, String address) {

        this.id = id;
        this.age = age;
        this.numberofrentals = numberofrentals;
        this.name = name;
        this.address = address;
    }

    public Integer getId() {

        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public Integer getnumberofrentals() {
        return numberofrentals;
    }

    public void setnumberofrentals(int numberofrentals) {
        this.numberofrentals = numberofrentals;
    }

    public String getName() {
        return name;
    }

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

    public String getAddress() {
        return address;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Client client = (Client) o;

        if (age != client.age) return false;
        if (numberofrentals != client.numberofrentals) return false;
        if (!id.equals(client.id)) return false;
        if (!name.equals(client.name)) return false;
        return address.equals(client.address);

    }

    @Override
    public int hashCode() {
        int result = id.hashCode();
        result = 31 * result + age;
        result = 31 * result + numberofrentals;
        result = 31 * result + name.hashCode();
        result = 31 * result + address.hashCode();
        return result;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        return "Client{" +
                "id=" + id +
                ", age=" + age +
                ", numberofrentals=" + numberofrentals +
                ", name='" + name + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

以下是JPAConfiguration的代码

@Configuration
@EnableJpaRepositories("repository")
@EnableTransactionManagement
@EnableCaching
public class JPAConfig {

    //    @Value("${db.jdbcURL}")
    private String jdbcURL = "jdbc:postgresql://localhost:5432/Shop";

    //    @Value("${db.user}")
    private String user = "postgres";

    //    @Value("${db.password}")
    private String password = "*****";

    //    @Value("${db.generateDDL}")
    private Boolean generateDDL = true;


    @Bean
    public DataSource dataSource() {
        PGPoolingDataSource dataSource = new PGPoolingDataSource();
        try {
            dataSource.setUrl(jdbcURL);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        dataSource.setUser(user);
        dataSource.setPassword(password);
        dataSource.setMaxConnections(4);

        return dataSource;
    }

    @Bean
    public EntityManagerFactory entityManagerFactory() {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setDatabase(Database.POSTGRESQL);
        vendorAdapter.setGenerateDdl(generateDDL);
        vendorAdapter.setShowSql(true);

        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(vendorAdapter);
        factory.setPackagesToScan("model");
        factory.setDataSource(dataSource());
        factory.afterPropertiesSet();
        return factory.getObject();
    }

    @Bean
    public EntityManager entityManager() {
        return entityManagerFactory().createEntityManager();
    }

    @Bean
    PlatformTransactionManager transactionManager() {
        JpaTransactionManager manager = new JpaTransactionManager();
        manager.setEntityManagerFactory(entityManagerFactory());
        return manager;
    }

    @Bean
    public HibernateExceptionTranslator hibernateExceptionTranslator() {
        return new HibernateExceptionTranslator();
    }

    @Bean
    public CacheManager cacheManager() {
        GuavaCacheManager guavaCacheManager = new GuavaCacheManager();
        guavaCacheManager.setCacheBuilder(CacheBuilder.newBuilder().expireAfterAccess(2, TimeUnit.HOURS));
        return guavaCacheManager;
    }
}

我连接但没有来自我的Client表的数据，这些数据具有以下完全相同的字段：id（PK），age，numberofrentals，name，address。什么想法有什么不对？我正在使用JpaRepository中的findall（）。我不明白可能是什么问题，一切似乎都是正确的。

如果还需要更多代码，我可以发布更多代码。

有没有办法调试这个或找出问题所在，因为到目前为止我只能得到连接和表的列表，其余的信息听起来不错？什么想法可能是错的？

Answer 1

当hibernate创建一个表时，由于某种原因它会使用所有小写字母创建它，并且它也会从那些中读取。我认为它访问区分大小写，所以我将数据添加到错误的表格中，而正确的表格始终为空。

Hibernate连接到Postgres数据库但它没有检索数据

1 个答案: