【发布时间】:2016-09-04 09:49:18
【问题描述】:
我有一个 Java Web 应用程序,我正在尝试通过类配置的 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,并且我看到了我所有的表,所以没关系。问题是我没有从表中得到任何数据。
这是我的客户模型:
@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 + '\'' +
'}';
}
}
这是 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;
}
}
我已连接,但我的客户表中没有数据,该表具有以下完全相同的字段:id(PK)、年龄、租房人数、姓名、地址。有什么想法有什么问题吗?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。
如果需要更多代码,我可以发布更多。
有什么方法可以调试或找出问题所在,因为到目前为止我只能获得连接和表格列表,其余信息听起来还不错吗? 有什么想法可能是错的吗?
【问题讨论】:
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打印 SQL 日志并手动尝试对数据库执行 SQL 命令。 how to log sql statements in spring-boot.
-
我想你需要数据库的方言
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是的,这是一个更大的问题。我正在使用 postgres,但我完全不确定 spirng boot 会做什么。虽然我检查了连接...它在那里。它会看到我的表,如果它们不存在,它甚至会创建表。它只是拒绝通过 Jpa 从他们那里读取任何内容
标签: java hibernate postgresql spring-mvc jpa