eclipse—在创建HibernateXMLMap文件时获取java.lang.nullpointerexception

svdrlsy4  于 2021-06-30  发布在  Java
关注(0)|答案(1)|浏览(363)

我是个冬眠的乞丐。我在eclipse上启动了一个java项目,并尝试使用hibernate。
首先,我在mysql上创建了java类和数据库(实际上它是空的,但不确定是否有与我的问题相关的链接)。
然后我导入了hibernate的库。我还导入了mysql的连接器mysql-connector-java-8.0.22.jar(我不知道是否必须这么做)。
我还添加了jboss工具,它允许我创建所有hibernate conf文件。
然后我创建了hibernate.cfg.xml,如下所示

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.password"></property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/match_simulator</property>
        <property name="hibernate.connection.username"></property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    </session-factory>
</hibernate-configuration>

在我的项目中,用户和密码不为空;)
最后,我尝试创建一个hibernate xmlMap文件,但得到了一个 java.lang.NullPointerException ,我不知道为什么。我只能用图片详细说明我是怎么做到的
第一步
第2步
第3步
第4步
我使用的是最新版本的eclipse(我猜是2020-09)、hibernate和jboss工具。
如果它也可以帮助你,我得到一个错误,当我试图测试我的连接。这是要测试的代码

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class Test {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Configuration config = new Configuration();
        SessionFactory sessionFactory = config.configure().buildSessionFactory();

        Session session = sessionFactory.openSession();
        session = sessionFactory.openSession();

        session.close();

    }

}

下面是我得到的错误

déc. 11, 2020 12:01:21 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate ORM core version 5.4.25.Final
déc. 11, 2020 12:01:22 PM org.hibernate.spatial.integration.SpatialService <init>
INFO: HHH80000001: hibernate-spatial integration enabled : true
déc. 11, 2020 12:01:22 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.1.2.Final}
déc. 11, 2020 12:01:22 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
déc. 11, 2020 12:01:22 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/match_simulator]
déc. 11, 2020 12:01:22 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=root, password=****}
déc. 11, 2020 12:01:22 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
déc. 11, 2020 12:01:22 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
déc. 11, 2020 12:01:23 PM org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator initiateService
WARN: HHH000342: Could not obtain connection to query metadata
java.lang.IllegalStateException: Cannot get a connection as the driver manager is not properly initialized
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:172)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:68)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:107)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:246)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:116)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:41)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.addConnections(DriverManagerConnectionProviderImpl.java:341)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.<init>(DriverManagerConnectionProviderImpl.java:260)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.<init>(DriverManagerConnectionProviderImpl.java:238)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections$Builder.build(DriverManagerConnectionProviderImpl.java:379)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:98)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:73)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:107)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:246)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:145)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:66)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.injectServices(DefaultIdentifierGeneratorFactory.java:152)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.injectDependencies(AbstractServiceRegistryImpl.java:286)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:243)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:176)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:127)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:86)
    at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:473)
    at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:84)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:689)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
    at metier.Test.main(Test.java:13)

déc. 11, 2020 12:01:23 PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
déc. 11, 2020 12:01:23 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 0, SQLState: 01S00
déc. 11, 2020 12:01:23 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: The server time zone value 'Paris, Madrid' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the 'serverTimezone' configuration property) to use a more specific time zone value if you want to utilize time zone support.
Exception in thread "main" org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:275)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.injectServices(DefaultIdentifierGeneratorFactory.java:152)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.injectDependencies(AbstractServiceRegistryImpl.java:286)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:243)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:176)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:127)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:86)
    at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:473)
    at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:84)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:689)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
    at metier.Test.main(Test.java:13)
Caused by: org.hibernate.exception.GenericJDBCException: Error calling Driver#connect
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:118)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:41)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.addConnections(DriverManagerConnectionProviderImpl.java:341)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.<init>(DriverManagerConnectionProviderImpl.java:260)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.<init>(DriverManagerConnectionProviderImpl.java:238)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections$Builder.build(DriverManagerConnectionProviderImpl.java:379)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:98)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:73)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:107)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:246)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:145)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:66)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263)
    ... 14 more
Caused by: java.sql.SQLException: The server time zone value 'Paris, Madrid' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the 'serverTimezone' configuration property) to use a more specific time zone value if you want to utilize time zone support.
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:129)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63)
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73)
    at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:76)
    at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:836)
    at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456)
    at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:246)
    at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:198)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
    ... 29 more
Caused by: com.mysql.cj.exceptions.InvalidConnectionAttributeException: The server time zone value 'Paris, Madrid' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the 'serverTimezone' configuration property) to use a more specific time zone value if you want to utilize time zone support.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:85)
    at com.mysql.cj.util.TimeUtil.getCanonicalTimezone(TimeUtil.java:134)
    at com.mysql.cj.protocol.a.NativeProtocol.configureTimezone(NativeProtocol.java:2186)
    at com.mysql.cj.protocol.a.NativeProtocol.initServerSession(NativeProtocol.java:2209)
    at com.mysql.cj.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:1318)
    at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:967)
    at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:826)
    ... 33 more
pinkon5k

pinkon5k1#

如果没有进一步的细节,很难给出答案。新产品工程师( NullPointerException )几乎可以在任何地方发生,因此需要堆栈跟踪来查看发生的位置。
您是部署到应用服务器还是开发javase应用程序?如果你只是想尝试一下,这里有一个教程:https://tools.jboss.org/documentation/howto/hibernate.html

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