java - 使用 hibernate 连接数据库时出错

Question

我正在尝试学习 Hibernate。这是我的第一个程序，但是我在编译时无法找出问题所在。我使用 Postgresql，它已经打开连接。

这是模型:

package org.javabrains.koushik.dto;

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity

public class UserDetails {
    @Id
    private int userId;
    private String userName;

    public int getUserId() {
        return userId;
    }
    public void setUserId(int userId) {
        this.userId = userId;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
}

测试类:

package org.koushik.hibernate;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.javabrains.koushik.dto.UserDetails;

public class HibernateTest {

    /**
     * @param args
     */
    public static void main(String[] args) {
        UserDetails user = new UserDetails();
        user.setUserId(1);
        user.setUserName("First User");

        @SuppressWarnings("deprecation")
        SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
        Session session = sessionFactory.openSession();
        session.beginTransaction();
        session.save(user);
        session.getTransaction().commit();

    }

}

还有 hibernate.cfg.xml:

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings -->
        <property name="connection.driver_class">org.postgresql.Driver</property>
        <property name="connection.url">jdbc:postgresql://host:5432/hibernatedb</property>
        <property name="connection.username">postgres</property>
        <property name="connection.password">06640265</property>

        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.PostgreSQLDialect</property>

        <!-- Enable Hibernate's automatic session context management -->
        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>

        <!-- Drop and re-create the database schema on startup -->
        <property name="hbm2ddl.auto">update</property>

        <mapping class="org.javabrains.koushik.dto.UserDetails"/>

    </session-factory>

</hibernate-configuration>

和日志:

Tem 06, 2013 12:02:47 AM org.hibernate.annotations.common.Version <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.2.Final}
Tem 06, 2013 12:02:47 AM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.2.3.Final}
Tem 06, 2013 12:02:47 AM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Tem 06, 2013 12:02:47 AM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
Tem 06, 2013 12:02:47 AM org.hibernate.cfg.Configuration configure
INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml
Tem 06, 2013 12:02:47 AM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040: Configuration resource: /hibernate.cfg.xml
Tem 06, 2013 12:02:47 AM org.hibernate.internal.util.xml.DTDEntityResolver resolveEntity
WARN: HHH000223: Recognized obsolete hibernate namespace http://hibernate.sourceforge.net/. Use namespace http://www.hibernate.org/dtd/ instead. Refer to Hibernate 3.6 Migration Guide!
Tem 06, 2013 12:02:48 AM org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041: Configured SessionFactory: null
Tem 06, 2013 12:02:48 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000402: Using Hibernate built-in connection pool (not for production use!)
Tem 06, 2013 12:02:48 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000115: Hibernate connection pool size: 1
Tem 06, 2013 12:02:48 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000006: Autocommit mode: false
Tem 06, 2013 12:02:48 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000401: using driver [org.postgresql.Driver] at URL [jdbc:postgresql://host:5432/hibernatedb]
Tem 06, 2013 12:02:48 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000046: Connection properties: {user=postgres, password=****}
Tem 06, 2013 12:02:50 AM org.hibernate.engine.jdbc.internal.JdbcServicesImpl configure
WARN: HHH000342: Could not obtain connection to query metadata : Bağlantı denemesi başarısız oldu.
Tem 06, 2013 12:02:50 AM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.PostgreSQLDialect
Tem 06, 2013 12:02:50 AM org.hibernate.engine.jdbc.internal.LobCreatorBuilder useContextualLobCreation
INFO: HHH000422: Disabling contextual LOB creation as connection was null
Tem 06, 2013 12:02:50 AM org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService
INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)
Tem 06, 2013 12:02:50 AM org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>
INFO: HHH000397: Using ASTQueryTranslatorFactory
Tem 06, 2013 12:02:50 AM org.hibernate.tool.hbm2ddl.SchemaUpdate execute
INFO: HHH000228: Running hbm2ddl schema update
Tem 06, 2013 12:02:50 AM org.hibernate.tool.hbm2ddl.SchemaUpdate execute
INFO: HHH000102: Fetching database metadata
Tem 06, 2013 12:02:50 AM org.hibernate.tool.hbm2ddl.SchemaUpdate execute
ERROR: HHH000319: Could not get database metadata
org.postgresql.util.PSQLException: Bağlantı denemesi başarısız oldu.
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:225)
    at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:64)
    at org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:136)
    at org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:29)
    at org.postgresql.jdbc3g.AbstractJdbc3gConnection.<init>(AbstractJdbc3gConnection.java:21)
    at org.postgresql.jdbc4.AbstractJdbc4Connection.<init>(AbstractJdbc4Connection.java:31)
    at org.postgresql.jdbc4.Jdbc4Connection.<init>(Jdbc4Connection.java:24)
    at org.postgresql.Driver.makeConnection(Driver.java:393)
    at org.postgresql.Driver.connect(Driver.java:267)
    at org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:204)
    at org.hibernate.tool.hbm2ddl.SuppliedConnectionProviderConnectionHelper.prepare(SuppliedConnectionProviderConnectionHelper.java:51)
    at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:194)
    at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:178)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:505)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1769)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1840)
    at org.koushik.hibernate.HibernateTest.main(HibernateTest.java:19)
Caused by: java.net.UnknownHostException: host
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at org.postgresql.core.PGStream.<init>(PGStream.java:60)
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:101)
    ... 16 more

Tem 06, 2013 12:02:50 AM org.hibernate.tool.hbm2ddl.SchemaUpdate execute
ERROR: HHH000299: Could not complete schema update
org.postgresql.util.PSQLException: Bağlantı denemesi başarısız oldu.
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:225)
    at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:64)
    at org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:136)
    at org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:29)
    at org.postgresql.jdbc3g.AbstractJdbc3gConnection.<init>(AbstractJdbc3gConnection.java:21)
    at org.postgresql.jdbc4.AbstractJdbc4Connection.<init>(AbstractJdbc4Connection.java:31)
    at org.postgresql.jdbc4.Jdbc4Connection.<init>(Jdbc4Connection.java:24)
    at org.postgresql.Driver.makeConnection(Driver.java:393)
    at org.postgresql.Driver.connect(Driver.java:267)
    at org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:204)
    at org.hibernate.tool.hbm2ddl.SuppliedConnectionProviderConnectionHelper.prepare(SuppliedConnectionProviderConnectionHelper.java:51)
    at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:194)
    at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:178)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:505)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1769)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1840)
    at org.koushik.hibernate.HibernateTest.main(HibernateTest.java:19)
Caused by: java.net.UnknownHostException: host
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at org.postgresql.core.PGStream.<init>(PGStream.java:60)
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:101)
    ... 16 more

Tem 06, 2013 12:02:51 AM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 0, SQLState: 08001
Tem 06, 2013 12:02:51 AM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: Bağlantı denemesi başarısız oldu.
Exception in thread "main" org.hibernate.exception.JDBCConnectionException: Could not open connection
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:132)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:221)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:157)
    at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:67)
    at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:160)
    at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1426)
    at org.koushik.hibernate.HibernateTest.main(HibernateTest.java:21)
Caused by: org.postgresql.util.PSQLException: Bağlantı denemesi başarısız oldu.
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:225)
    at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:64)
    at org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:136)
    at org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:29)
    at org.postgresql.jdbc3g.AbstractJdbc3gConnection.<init>(AbstractJdbc3gConnection.java:21)
    at org.postgresql.jdbc4.AbstractJdbc4Connection.<init>(AbstractJdbc4Connection.java:31)
    at org.postgresql.jdbc4.Jdbc4Connection.<init>(Jdbc4Connection.java:24)
    at org.postgresql.Driver.makeConnection(Driver.java:393)
    at org.postgresql.Driver.connect(Driver.java:267)
    at org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:204)
    at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:292)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:214)
    ... 5 more
Caused by: java.net.UnknownHostException: host
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at org.postgresql.core.PGStream.<init>(PGStream.java:60)
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:101)
    ... 16 more

我认为这个问题很搞笑，对此感到抱歉，但这对我来说只是一个起点。

Answer 1

在您的配置中

  <property name="connection.url">jdbc:postgresql://host:5432/hibernatedb</property>

我认为这个网址不正确。至少您可以尝试 jdbc:postgresql://localhost:5432/hibernatedb 或其他一些端点。

因为错误日志表明问题是“Caused by: java.net.UnknownHostException: host”