Hibernate隐秩序系列之---基础

hibernate作为一个著名的持久层ORM(object relationship Map)框架而深受人们喜欢。最近出了Hibernate5，我也先尝尝鲜。
第一步：下载相关的jar包，由于使用mysql做为数据源，所有除了需要下载Hibernate5之外，还要下载mysql-connector-/J驱动库。
第二步：建立java Application　项目。
第三步：导包，必须的lib/required下的Hibernate包，导入mysql-connector-java的包。
第四步：建库，创建需要的mysql数据库,create database school;
第五步：建表，创建表create table stu(id int primary key auto_increment,name varchar(32),sex char,idcard varchar(32));
第六步：主配置文件hibernate.cfg.xml，编写配置文件放到项目的src目录之下（放入此目录的配置文件将在编译后自动放到bin目录下)，配置文件如下

<?xml version='1.0' encoding='utf-8'?>
<!--
  ~ Hibernate, Relational Persistence for Idiomatic Java
  ~
  ~ License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  ~ See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  -->
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "">

<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings com.mysql.jdbc.Driver来自mysql-connector-java包-->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://127.0.0.1:3306/school</property>
        <property name="connection.username">root</property>
        <property name="connection.password">7867761</property>

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

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

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

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

        <!-- Drop and re-create the database schema on startup数据对象的四种操作方式
                    create：表示启动的时候先drop，再create
                    create-drop: 也表示创建，只不过再系统关闭前执行一下drop
                    update: 这个操作启动的时候会去检查schema是否一致，如果不一致会做scheme更新
                    validate: 启动时验证现有schema与你配置的hibernate是否一致，如果不一致就抛出异常，并不做更新
         -->
        <property name="hbm2ddl.auto">create</property>
        <property name="log4j.logger.org.hibernate.type">trace</property>
        <mapping resource="config/Test.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

第七步：创建Hibernate Session对象

点击(此处)折叠或打开

public static void main( String[] args )
{
System.out.print("测试开始");
final StandardServiceRegistryBuilder _builder = new StandardServiceRegistryBuilder();
final StandardServiceRegistry registry = _builder.configure("hibernate.cfg.xml")
.build();
Transaction _Transaction = null;
try
{
MetadataSources source = new MetadataSources(registry);
org.hibernate.boot.Metadata md = source.buildMetadata();
SessionFactory _Factory = md.buildSessionFactory();
Session _Session = _Factory.openSession();
_Transaction = _Session.beginTransaction();
_Transaction.begin();
_Transaction.commit();
}
catch( Exception _e )
{
if( _Transaction != null )
_Transaction.rollback();
System.out.print( _e.getMessage());
}
return ;
}

错误1：由于在编码时忘记传递MetadataSources source = new MetadataSources(registry);中registry 的参数出现如下错误

十一月 04, 2015 9:40:05 上午 org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator initiateService
WARN: HHH000342: Could not obtain connection to query metadata : The application must supply JDBC connections
Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]

错误2：hibernate.cfg.xml中的jdbc:mysql://127.0.0.1:3306/school的school配置成了stu导致

测试开始十一月 04, 2015 9:44:07 上午 org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.0.2.Final}
十一月 04, 2015 9:44:07 上午 org.hibernate.cfg.Environment
INFO: HHH000206: hibernate.properties not found
十一月 04, 2015 9:44:07 上午 org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
十一月 04, 2015 9:44:08 上午 org.hibernate.annotations.common.reflection.java.JavaReflectionManager
INFO: HCANN000001: Hibernate Commons Annotations {5.0.0.Final}
十一月 04, 2015 9:44:08 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH000402: Using Hibernate built-in connection pool (not for production use!)
十一月 04, 2015 9:44:08 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://127.0.0.1:3306/stu]
十一月 04, 2015 9:44:08 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000046: Connection properties: {user=root, password=****}
十一月 04, 2015 9:44:08 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000006: Autocommit mode: false
十一月 04, 2015 9:44:08 上午 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]

由于这类错误非常难于寻找原因，因为我为程序加入了catch语句，来捕获了异常，如果去掉catch,由于eclipse输出的异常后的堆栈信息

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:244)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:208)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:189)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:217)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:189)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418)
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
at org.hibernate.boot.MetadataSources.buildMetadata(MetadataSources.java:179)
at test.HibernateTest.main(HibernateTest.java:21)
Caused by: org.hibernate.exception.SQLGrammarException: Error calling Driver#connect
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:106)
at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator$1$1.convert(BasicConnectionCreator.java:101)
at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:123)
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.configure(DriverManagerConnectionProviderImpl.java:89)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:217)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:189)
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:88)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:234)
... 13 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown database 'stu'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
at com.mysql.jdbc.Util.getInstance(Util.java:387)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:941)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3870)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3806)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:871)
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1686)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1207)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2254)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2285)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2084)
at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:795)
at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:44)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:400)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:327)
at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
... 23 more

错误原因非常明确　数据库不存在

Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown database 'stu'

第八步：创建orm对象

package test;

public class stu {

    private int id;
    private String name;
    private char sex;
    private String idcard;
    public stu( )
    {

    }
    public void setId( int _id )
    {
        id = _id;
    }
    public void setName( String _name )
    {
        name= _name;
    }
    public void setSex(char _sex )
    {
        sex = _sex;
    }
    public void setIdCard( String _idcard )
    {
        idcard= _idcard;
    }
    public int getId( )
    {
        return id;
    }
    public String getName( )
    {
        return name;
    }
    public char getSex( )
    {
        return sex;
    }
    public String getIdcard( )
    {
        return idcard;
    }
}

第九步：编写对象映射文件，在src下创建config文件夹，创建Test.hbm.xml文件，文件内容如下

<?xml version="1.0"?>

<!--
  ~ Hibernate, Relational Persistence for Idiomatic Java
  ~
  ~ License: GNU Lesser General Public License (LGPL), version 2.1 or later.
  ~ See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
  -->
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "">

<hibernate-mapping package="test">

    <class name="stu" table="stu">
        <id name="id" column="id">
            <generator class="identity"/>

        </id>

        <property name="name" type="java.lang.String" column="name"/>
        <property name="sex" type="java.lang.Character" column="sex"/>
       <property name="idcard" type="java.lang.String" column="idcard"/>

    </class>

</hibernate-mapping>

<!-- 主键的生成方式，不同的数据库采用不同的生成方式
            sequence :oracle专用需要
                          <generator class = "sequence">
                                <param name="sequence">
                                序列名
                                </param>
                          </generator>
            identiy :oracel之外的数据库主键生成方式
            native :让hibernate自动选择主键生成方式　，根据hibernate.cfg.xml中配置的方言来区分，配置方式与sequence一样
            increment :让hibernate自主生成主键，通过读取表中的最大ＩＤ来生成，但当数据库并发量大时，会出现重复的主键，不推荐使用
　 assinged :程序员自己生成主键，不自动生成
            hilo/uuid :通过uuid/hilo的算法生成一个长字符串，不会重复，但没有任何规律。
            -->

第十步：添加代码为stu表添加一行记录

            _Transaction = _Session.beginTransaction();
            _Transaction.begin();
            stu _stu = new stu();
            _stu.setName("李正杨");
            _stu.setSex('B');
            _stu.setIdCard("130624198723053342");
            _Session.save( _stu );
            _Transaction.commit();

运行后，异常如下

Exception in thread "main" org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:123)
at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:77)
at org.hibernate.internal.SessionFactoryImpl.(SessionFactoryImpl.java:346)
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:444)
at org.hibernate.boot.internal.MetadataImpl.buildSessionFactory(MetadataImpl.java:170)
at test.HibernateTest.main(HibernateTest.java:22)
Caused by: org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer]
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:91)
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructDefaultTuplizer(EntityTuplizerFactory.java:116)
at org.hibernate.tuple.entity.EntityMetamodel.(EntityMetamodel.java:388)
at org.hibernate.persister.entity.AbstractEntityPersister.(AbstractEntityPersister.java:508)
at org.hibernate.persister.entity.SingleTableEntityPersister.(SingleTableEntityPersister.java:124)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:96)
... 5 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:88)
... 14 more
Caused by: org.hibernate.PropertyNotFoundException: Could not locate setter method for property [test.stu#idcard]
at org.hibernate.internal.util.ReflectHelper.findSetterMethod(ReflectHelper.java:475)
at org.hibernate.property.access.internal.PropertyAccessBasicImpl.(PropertyAccessBasicImpl.java:44)
at org.hibernate.property.access.internal.PropertyAccessStrategyBasicImpl.buildPropertyAccess(PropertyAccessStrategyBasicImpl.java:27)
at org.hibernate.mapping.Property.getGetter(Property.java:299)
at org.hibernate.tuple.entity.PojoEntityTuplizer.buildPropertyGetter(PojoEntityTuplizer.java:270)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.(AbstractEntityTuplizer.java:145)
at org.hibernate.tuple.entity.PojoEntityTuplizer.(PojoEntityTuplizer.java:63)

错误原因非常明确
Could not locate setter method for property [test.stu#idcard]
Set函数写的不符合规范，这里需要说明一下hibernate的映射格式，set####,get####其中####代表的是属性，一定要与定义的属性一致，包括大小写，第一个字母除外。
修改错误如下将大写的C改成小写调用处也修改

    public void setIdcard( String _idcard )
    {
        idcard= _idcard;
    }

            stu _stu = new stu();
            _stu.setName("李正杨");
            _stu.setSex('B');
            _stu.setIdcard("130624198723053342");

            _Session.save( _stu );

第十一步：重新运行成功

Hibernate: drop table if exists stu
Hibernate: create table stu (id integer not null, name varchar(255), sex char(1), idcard varchar(255), primary key (id))
十一月 04, 2015 10:08:25 上午 org.hibernate.tool.hbm2ddl.SchemaExport execute
INFO: HHH000230: Schema export complete
Hibernate: select max(id) from stu
Hibernate: insert into stu (name, sex, idcard, id) values (?, ?, ?, ?

这也验证了Create模式下，确实是先删除表，再创建表，然后插入了一行记录。