Hibernate最基础的示例
有关Spring的知识大部分都已经温习完毕,今天开始转向Hibernate的温习工作了必须包hibernate-distribution-3.5.3-Final\hibernate3.jar hibernate-distribution-3.5.3-Final\lib\required\slf4j-api-1.5.8.jar hibernate-distribution-3.5.3-Final\lib\required\slf4j-api-1.5.8.jar hibernate-distribution-3.5.3-Final\lib\required\slf4j-api-1.5.8.jar hibernate-distribution-3.5.3-Final\lib\required\slf4j-api-1.5.8.jar hibernate-distribution-3.5.3-Final\lib\required\slf4j-api-1.5.8.jar首先在hibernate资源包中找到:hibernate-distribution-3.5.3-Final\project\tutorials\web\src\main\resources\hibernate.cfg.xml,将这个配置文件复制到你的项目SRC目录下,然后根据实际情况进行适当修改,我的示例中修改后为Xml代码 1. <span style="font-size: large;"><span style="font-size: large;"><?xml version="1.0" encoding="utf-8" ?> 2. <!DOCTYPE hibernate-configuration PUBLIC 3. "-//Hibernate/Hibernate Configuration DTD 3.0//EN" 4. "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> 5. <hibernate-configuration> 6. <session-factory> 7. <!--数据库连接设置--> 8. <property name="connection.driver_class">com.mysql.jdbc.Driver</property> 9. <property name="connection.url">jdbc:mysql:///test</property> 10. <property name="connection.username">root</property> 11. <property name="connection.password">root</property> 12. 13. <!--JDBC连接池大小--> 14. <property name="connection.pool_size">2</property> 15. <!-- 数据库语言 --> 16. <property name="dialect">org.hibernate.dialect.MySQLDialect</property> 17. <!-- Hibernate当前的会话上下文 --> 18. <property name="current_session_context_class">org.hibernate.context.ManagedSessionContext</property> 19. <!-- 禁用二级缓存 --> 20. <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property> 21. <!-- 控制台显示SQL语句 --> 22. <property name="show_sql">true</property> 23. <!-- 格式化SQL语句 --> 24. <property name="hibernate.format_sql">true</property> 25. 26. <!-- 27. 启动时删数据库中的表,然后创建,退出时不删除数据表 28. <property name="hbm2ddl.auto">create</property> 29. --> 30. <!-- 31. 启动时删数据库中的表,然后创建,退出时自动删除所有表 32. <property name="hbm2ddl.auto">create-drop</property> 33. --> 34. <!-- 35. 自动修改,如果表结构与实体类不一致,那么就更新表结构,数据会保留 36. (如果原表不存在,就创建新表;如果缺少相应的字段,就加入;对于原来存在的多余字段,不作处理) 37. <property name="hbm2ddl.auto">update</property> 38. --> 39. <!-- 40. 自动校验,如果表结构与实体类不一致,那么不做任何操作,报错 41. <property name="hbm2ddl.auto">validate</property> 42. --> 43. <!-- Drop and re-create the database schema on startup --> 44. <property name="hbm2ddl.auto">create</property> 45. 46. <!-- 实体关系映射文件 --> 47. <mapping resource="com/javacrazyer/domain/Student.hbm.xml"/> 48. </session-factory> 49. </hibernate-configuration></span></span> <?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> <!--数据库连接设置--> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql:///test</property> <property name="connection.username">root</property> <property name="connection.password">root</property> <!--JDBC连接池大小--> <property name="connection.pool_size">2</property> <!-- 数据库语言 --> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <!-- Hibernate当前的会话上下文 --> <property name="current_session_context_class">org.hibernate.context.ManagedSessionContext</property> <!-- 禁用二级缓存 --> <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property> <!-- 控制台显示SQL语句 --> <property name="show_sql">true</property> <!-- 格式化SQL语句 --> <property name="hibernate.format_sql">true</property><!--启动时删数据库中的表,然后创建,退出时不删除数据表 <property name="hbm2ddl.auto">create</property>--><!--启动时删数据库中的表,然后创建,退出时自动删除所有表 <property name="hbm2ddl.auto">create-drop</property>--><!--自动修改,如果表结构与实体类不一致,那么就更新表结构,数据会保留(如果原表不存在,就创建新表;如果缺少相应的字段,就加入;对于原来存在的多余字段,不作处理)<property name="hbm2ddl.auto">update</property>--><!--自动校验,如果表结构与实体类不一致,那么不做任何操作,报错 <property name="hbm2ddl.auto">validate</property>--> <!-- Drop and re-create the database schema on startup --> <property name="hbm2ddl.auto">create</property> <!-- 实体关系映射文件 --> <mapping resource="com/javacrazyer/domain/Student.hbm.xml"/></session-factory></hibernate-configuration> 数据库方言一定要设定对,跟数据库驱动匹配org.hibernate.dialect.MySQLDialect 否则的话就会出现下面这个错误Java代码 1. <span style="font-size: large;"><span style="font-size: large;">Unknown table 'system_sequences' in information_schema</span></span> Unknown table 'system_sequences' in information_schema 其次,看看实体类Student.javaJava代码 1. <span style="font-size: large;"><span style="font-size: large;">package com.javacrazyer.domain; 2. 3. import java.util.Date; 4. 5. /** 6. * 学生实体类 --> 按JavaBean的形式定义 7. * 8. */ 9. public class Student { 10. private int id; //OID 对象标识符 11. private String name; 12. private int age; 13. private boolean gender; 14. private Date birthday; 15. private double score; 16. 17. public int getId() { 18. return id; 19. } 20. public void setId(int id) { 21. this.id = id; 22. } 23. public String getName() { 24. return name; 25. } 26. public void setName(String name) { 27. this.name = name; 28. } 29. public int getAge() { 30. return age; 31. } 32. public void setAge(int age) { 33. this.age = age; 34. } 35. public boolean isGender() { 36. return gender; 37. } 38. public void setGender(boolean gender) { 39. this.gender = gender; 40. } 41. public Date getBirthday() { 42. return birthday; 43. } 44. public void setBirthday(Date birthday) { 45. this.birthday = birthday; 46. } 47. public double getScore() { 48. return score; 49. } 50. public void setScore(double score) { 51. this.score = score; 52. } 53. 54. @Override 55. public String toString(){ 56. return "id=" + id + ",name=" + name + ",gender=" + gender + ",age=" + age 57. + ",birthday=" + this.birthday + ",score=" + score; 58. } 59. 60. }</span></span> package com.javacrazyer.domain;import java.util.Date;/** * 学生实体类 --> 按JavaBean的形式定义 * */public class Student {private int id; //OID 对象标识符private String name;private int age;private boolean gender;private Date birthday;private double score;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public boolean isGender() {return gender;}public void setGender(boolean gender) {this.gender = gender;}public Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday = birthday;}public double getScore() {return score;}public void setScore(double score) {this.score = score;}@Overridepublic String toString(){return "id=" + id + ",name=" + name + ",gender=" + gender + ",age=" + age+ ",birthday=" + this.birthday + ",score=" + score;}} 实体关系映射文件Student.hbm.xml,具体内容也可以参照hibernate资源包下:hibernate-distribution-3.5.3Final\project\tutorials\web\src\main\resources\org\hibernate\tutorial\domain\Person.hbm.xml那么进行修改后的内容为Xml代码 1. <span style="font-size: large;"><span style="font-size: large;"><?xml version="1.0" encoding="UTF-8"?> 2. <!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" > 3. <hibernate-mapping> 4. <class name="com.javacrazyer.domain.Student" table="student"> 5. <id name="id" column="id"> 6. <generator column="name"/> 9. <property name="age"/> 10. <property name="gender"/> 11. <property name="birthday"/> 12. <property name="score"/> 13. </class> 14. </hibernate-mapping></span></span> <?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" ><hibernate-mapping><class name="com.javacrazyer.domain.Student" table="student"><id name="id" column="id"> <generator column="name"/> <property name="age"/> <property name="gender"/> <property name="birthday"/> <property name="score"/></class></hibernate-mapping> 现在介绍下hbm.xml映射文件中各种属性的介绍吧1.class 节点name: 类名table: 类对应表名,默认为类名称dynamic-update: 生成更新字段时,只包含发生变动的字段,默认为false。dynamic-insert: 生成insert语句时仅包含非null字段Proxy: 代理类,默认为空discriminator-value: 子类辨别标识用于多态支持where: 通过限定条件查询结果集。如:查询有籍在校学生的信息可以使用"where studentstatus='0'"2.id节点1.column 字段名称2.type 字段类型3.length 字段长度4.unsaved-value 用于判断对象值是否已经保存5.generator-class 主键产生方式 assigned hilo seqhilo increment identity sequence native uuid.hex uuid.string foreign---------------------------------------------------------------------------主键产生方式说明increment(递增) 用于为long, short或者int类型生成唯一标识。只有在没有其他进程往同一张表中插入数据时才能使用。 在集群下不要使用。identity 对DB2,MySQL, MS SQL Server, Sybase和HypersonicSQL的内置标识字段提供支持。返回的标识符是long, short 或者int类型的。sequence (序列) 在DB2,PostgreSQL, Oracle, SAP DB, McKoi中使用序列(sequence),而在Interbase中使用生成器(generator)。返回的标识符是long, short或者 int类型的。hilo (高低位) 使用一个高/低位算法来高效的生成long, short或者 int类型的标识符。给定一个表和字段(默认分别是是hibernate_unique_key 和next_hi)作为高位值得来源。高/低位算法生成的标识符只在一个特定的数据库中是唯一的。在使用JTA获得的连接或者用户自行提供的连接中,不要 使用这种生成器。seqhilo(使用序列的高低位) 使用一个高/低位算法来高效的生成long, short或者 int类型的标识符,给定一个数据库序列(sequence)的名字。uuid.hex 用一个128-bit的UUID算法生成字符串类型的标识符。在一个网络中唯一(使用了IP地址)。UUID被编码为一个32位16进制数字的字符串。uuid.string 使用同样的UUID算法。UUID被编码为一个16个字符长的任意ASCII字符组成的字符串。不能使用在PostgreSQL数据库中native(本地) 根据底层数据库的能力选择identity, sequence 或者hilo中的一个。assigned(程序设置) 让应用程序在save()之前为对象分配一个标示符。foreign(外部引用)-------------------------------------------------3.property 节点1.column 数据库表字段名称2.type 类型3.length 长度4.not-null 字段是否允许为空5.unique 字段是否允许唯一(是否允许重复值)6.insert insert操作时,是否允许包含本字段数值7.update update操作时,是否包含本字段数据特别说明现在有个问题,按平常思路就是,得在数据库中创建一个student表吧,字段及类型得与Student类吻合,其实不用,为什么这么说,因为在 hibernate.cfg.xml中 <property name="hibernate.hbm2ddl.auto">update</property>这句话配置的值为update就表示没有表的情况下会在执行数据库操作前自动创建数据库表,这下就省了好多事了不过,如果你非要手工去创建,写SQL语句在数据库工具中也没必要,hibernate有相应的API支持你生成对应的数据库表下面这个类就就可以创建数据库表的类DBScriptExport .JavaJava代码 1. <span style="font-size: large;"><span style="font-size: large;">package com.javacrazyer.common; 2. 3. import org.hibernate.cfg.Configuration; 4. import org.hibernate.tool.hbm2ddl.SchemaExport; 5. 6. /** 7. * 根据对象关系映射文件直接生成数据库表或生成建表的脚本 8. * 9. */ 10. public class DBScriptExport { 11. 12. public static void main(String[] args) { 13. export2File("dbcript.sql"); 14. } 15. 16. public static void export2DB(){ 17. //加载Hibernate的全局配置文件 18. Configuration config = new Configuration().configure(); 19. SchemaExport export = new SchemaExport(config); 20. export.create(true, true); 21. } 22. 23. public static void export2File(String dest){ 24. Configuration config = new Configuration().configure(); 25. SchemaExport export = new SchemaExport(config); 26. 27. export.setOutputFile(dest) 28. .setDelimiter(";") 29. .setFormat(true) 30. .create(true, false); 31. } 32. 33. } 34. </span></span> package com.javacrazyer.common;import org.hibernate.cfg.Configuration;import org.hibernate.tool.hbm2ddl.SchemaExport;/** * 根据对象关系映射文件直接生成数据库表或生成建表的脚本 * */public class DBScriptExport {public static void main(String[] args) {export2File("dbcript.sql");}public static void export2DB(){//加载Hibernate的全局配置文件Configuration config = new Configuration().configure();SchemaExport export = new SchemaExport(config);export.create(true, true);}public static void export2File(String dest){Configuration config = new Configuration().configure();SchemaExport export = new SchemaExport(config);export.setOutputFile(dest).setDelimiter(";").setFormat(true).create(true, false);}} 获取session的HibernateUtil.javaJava代码 1. <span style="font-size: large;"><span style="font-size: large;">package com.javacrazyer.common; 2. 3. import org.hibernate.Session; 4. import org.hibernate.SessionFactory; 5. import org.hibernate.cfg.Configuration; 6. 7. /** 8. * Hibernate工具类 9. * 10. */ 11. public class HibernateUtil { 12. private static final SessionFactory factory; 13. 14. private HibernateUtil(){} 15. 16. static{ 17. //加载Hibernate全局配置文件,根据配置信息创建SessionFactory工厂实例 18. factory = new Configuration().configure().buildSessionFactory(); 19. } 20. 21. public static SessionFactory getSessionFactory(){ 22. return factory; 23. } 24. 25. public static Session getSession(){ 26. return factory.openSession(); 27. } 28. } 29. </span></span> package com.javacrazyer.common;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;/** * Hibernate工具类 * */public class HibernateUtil {private static final SessionFactory factory;private HibernateUtil(){}static{//加载Hibernate全局配置文件,根据配置信息创建SessionFactory工厂实例factory = new Configuration().configure().buildSessionFactory();}public static SessionFactory getSessionFactory(){return factory;}public static Session getSession(){return factory.openSession();}} 最后的测试类HibernateTest.javaJava代码 1. <span style="font-size: large;"><span style="font-size: large;">package com.javacrazyer.test; 2. 3. import java.util.Date; 4. import java.util.List; 5. 6. import org.hibernate.Criteria; 7. import org.hibernate.HibernateException; 8. import org.hibernate.Query; 9. import org.hibernate.Session; 10. import org.hibernate.Transaction; 11. import org.hibernate.criterion.Order; 12. import org.junit.Assert; 13. import org.junit.Test; 14. 15. import com.javacrazyer.common.HibernateUtil; 16. import com.javacrazyer.domain.Student; 17. 18. /** 19. * 使用Hibernate API完成CRUD 20. * 更复杂的持久化操作需要使用到Query接口 21. * 22. */ 23. public class HibernateTest { 24. 25. @Test 26. public void testAdd(){ 27. Student stu = new Student(); 28. stu.setName("test"); 29. stu.setBirthday(new Date()); 30. stu.setAge(1); 31. stu.setGender(true); 32. stu.setScore(66.8); 33. 34. //利用工厂打开一个Session实例 35. Session session = HibernateUtil.getSession(); 36. 37. //开启一个操作事务 38. Transaction tx = session.beginTransaction(); 39. 40. //利用session进行持久化操作 41. session.save(stu); 42. 43. //提交事务 44. tx.commit(); 45. 46. //关闭Session 47. session.close(); 48. } 49. 50. @Test 51. public void getStu(){ 52. 53. //持久化管理器 54. Session session = null; 55. Transaction tx = null; 56. try{ 57. session = HibernateUtil.getSession(); 58. 59. tx = session.beginTransaction(); 60. 61. //根据ID查询实体对象 62. Student stu = (Student)session.get(Student.class, 1); 63. 64. Assert.assertNotNull(stu); 65. System.out.println(stu); 66. 67. tx.commit(); 68. }catch(HibernateException he){ 69. he.printStackTrace(); 70. tx.rollback(); 71. }finally{ 72. if(null != session && session.isOpen()){ 73. try{ 74. session.close(); 75. }catch(HibernateException e){ 76. e.printStackTrace(); 77. } 78. } 79. } 80. } 81. 82. @Test 83. public void testUpdate(){ 84. Session session = null; 85. 86. try{ 87. session = HibernateUtil.getSession(); 88. 89. session.beginTransaction(); 90. 91. Student stu = (Student)session.get(Student.class, 1); 92. stu.setName("zs"); 93. stu.setScore(52.1); 94. 95. session.update(stu); 96. 97. session.getTransaction().commit(); 98. }catch(HibernateException e){ 99. Assert.fail(); 100. e.printStackTrace(); 101. session.getTransaction().rollback(); 102. }finally{ 103. if(session != null && session.isOpen()){ 104. session.close(); 105. } 106. } 107. } 108. 109. @Test 110. public void testDelete(){ 111. Session session = null; 112. 113. try{ 114. session = HibernateUtil.getSession(); 115. //session.beginTransaction(); 116. 117. Student stu = (Student)session.get(Student.class, 2); 118. System.out.println(stu); 119. session.delete(stu); 120. 121. //session.getTransaction().commit(); 122. }catch(HibernateException e){ 123. Assert.fail(); 124. e.printStackTrace(); 125. //session.getTransaction().rollback(); 126. }finally{ 127. if(session != null && session.isOpen()){ 128. session.close(); 129. } 130. } 131. } 132. 133. @Test 134. public void testGet(){ 135. Session session = null; 136. 137. try{ 138. session = HibernateUtil.getSession(); 139. session.beginTransaction(); 140. 141. Student stu = (Student)session.get(Student.class, 2); 142. 143. System.out.println(stu); 144. 145. Student stu2 = (Student) session.get(Student.class, 2); 146. 147. System.out.println(stu2); 148. 149. session.getTransaction().commit(); 150. }catch(HibernateException e){ 151. Assert.fail(); 152. e.printStackTrace(); 153. session.getTransaction().rollback(); 154. }finally{ 155. if(session != null && session.isOpen()){ 156. session.close(); 157. } 158. } 159. } 160. 161. @Test 162. public void testGet2(){ 163. Session session = null; 164. 165. session = HibernateUtil.getSession(); 166. session.beginTransaction(); 167. Student stu = (Student)session.get(Student.class, 2); 168. System.out.println(stu); 169. session.getTransaction().commit(); 170. session.close(); 171. 172. session = HibernateUtil.getSession(); 173. session.beginTransaction(); 174. Student stu2 = (Student) session.get(Student.class, 2); 175. System.out.println(stu2); 176. session.getTransaction().commit(); 177. session.close(); 178. } 179. 180. @SuppressWarnings("unchecked") 181. @Test 182. public void testQuery(){ 183. Session session = null; 184. try{ 185. session = HibernateUtil.getSession(); 186. session.beginTransaction(); 187. 188. Query query = session.createQuery("from Student"); 189. List<Student> stus = query.list(); 190. 191. for(Student stu : stus){ 192. System.out.println(stu); 193. } 194. 195. session.getTransaction().commit(); 196. 197. }catch(HibernateException e){ 198. e.printStackTrace(); 199. session.getTransaction().rollback(); 200. }finally{ 201. if(session != null && session.isOpen()){ 202. session.close(); 203. } 204. } 205. } 206. 207. @SuppressWarnings("unchecked") 208. @Test 209. public void testCriteria(){ 210. Session session = null; 211. try{ 212. session = HibernateUtil.getSession(); 213. session.beginTransaction(); 214. 215. Criteria criteria = session.createCriteria(Student.class); 216. 217. List<Student> stus = criteria.addOrder(Order.desc("id")).list(); 218. 219. for(Student stu : stus){ 220. System.out.println(stu); 221. } 222. 223. session.getTransaction().commit(); 224. 225. }catch(HibernateException e){ 226. e.printStackTrace(); 227. session.getTransaction().rollback(); 228. }finally{ 229. if(session != null && session.isOpen()){ 230. session.close(); 231. } 232. } 233. } 234. 235. }</span></span> package com.javacrazyer.test;import java.util.Date;import java.util.List;import org.hibernate.Criteria;import org.hibernate.HibernateException;import org.hibernate.Query;import org.hibernate.Session;import org.hibernate.Transaction;import org.hibernate.criterion.Order;import org.junit.Assert;import org.junit.Test;import com.javacrazyer.common.HibernateUtil;import com.javacrazyer.domain.Student;/** * 使用Hibernate API完成CRUD * 更复杂的持久化操作需要使用到Query接口 * */public class HibernateTest {@Testpublic void testAdd(){Student stu = new Student();stu.setName("test");stu.setBirthday(new Date());stu.setAge(1);stu.setGender(true);stu.setScore(66.8);//利用工厂打开一个Session实例Session session = HibernateUtil.getSession();//开启一个操作事务Transaction tx = session.beginTransaction();//利用session进行持久化操作session.save(stu);//提交事务tx.commit();//关闭Sessionsession.close();}@Testpublic void getStu(){//持久化管理器Session session = null;Transaction tx = null;try{session = HibernateUtil.getSession();tx = session.beginTransaction();//根据ID查询实体对象Student stu = (Student)session.get(Student.class, 1);Assert.assertNotNull(stu);System.out.println(stu);tx.commit();}catch(HibernateException he){he.printStackTrace();tx.rollback();}finally{if(null != session && session.isOpen()){try{session.close();}catch(HibernateException e){e.printStackTrace();}}}}@Testpublic void testUpdate(){Session session = null;try{session = HibernateUtil.getSession();session.beginTransaction();Student stu = (Student)session.get(Student.class, 1);stu.setName("zs");stu.setScore(52.1);session.update(stu);session.getTransaction().commit();}catch(HibernateException e){Assert.fail();e.printStackTrace();session.getTransaction().rollback();}finally{if(session != null && session.isOpen()){session.close();}}}@Testpublic void testDelete(){Session session = null;try{session = HibernateUtil.getSession();//session.beginTransaction();Student stu = (Student)session.get(Student.class, 2);System.out.println(stu);session.delete(stu);//session.getTransaction().commit();}catch(HibernateException e){Assert.fail();e.printStackTrace();//session.getTransaction().rollback();}finally{if(session != null && session.isOpen()){session.close();}}}@Testpublic void testGet(){Session session = null;try{session = HibernateUtil.getSession();session.beginTransaction();Student stu = (Student)session.get(Student.class, 2);System.out.println(stu);Student stu2 = (Student) session.get(Student.class, 2);System.out.println(stu2);session.getTransaction().commit();}catch(HibernateException e){Assert.fail();e.printStackTrace();session.getTransaction().rollback();}finally{if(session != null && session.isOpen()){session.close();}}}@Testpublic void testGet2(){Session session = null;session = HibernateUtil.getSession();session.beginTransaction();Student stu = (Student)session.get(Student.class, 2);System.out.println(stu);session.getTransaction().commit();session.close();session = HibernateUtil.getSession();session.beginTransaction();Student stu2 = (Student) session.get(Student.class, 2);System.out.println(stu2);session.getTransaction().commit();session.close();}@SuppressWarnings("unchecked")@Testpublic void testQuery(){Session session = null;try{session = HibernateUtil.getSession();session.beginTransaction();Query query = session.createQuery("from Student");List<Student> stus = query.list();for(Student stu : stus){System.out.println(stu);}session.getTransaction().commit();}catch(HibernateException e){e.printStackTrace();session.getTransaction().rollback();}finally{if(session != null && session.isOpen()){session.close();}}}@SuppressWarnings("unchecked")@Testpublic void testCriteria(){Session session = null;try{session = HibernateUtil.getSession();session.beginTransaction();Criteria criteria = session.createCriteria(Student.class);List<Student> stus = criteria.addOrder(Order.desc("id")).list();for(Student stu : stus){System.out.println(stu);}session.getTransaction().commit();}catch(HibernateException e){e.printStackTrace();session.getTransaction().rollback();}finally{if(session != null && session.isOpen()){session.close();}}}} 补充说明:如果在hibernate.cfg.xml中配置的是 <property name="hibernate.hbm2ddl.auto">create</property>这种配置前提是表已经存在在这种情况下,只要你在项目的src下新建一个文件夹命名为 import.sql,并且里面写上数据库插入语句,那么就会执行插入操作,为什么只是插入,这得跟create值的这种创建啊方式有关,它是启动 hibernate时先删除已存在的表,后新建表,新建的表本身就是空的,当然只能进行插入操作了import.sqlJava代码 1. <span style="font-size: large;">insert into student(name,age,gender,birthday,score) values('test2',10,false,now(),11.2);</span> insert into student(name,age,gender,birthday,score) values('test2',10,false,now(),11.2); 这时,如果你在执行上面那个测试类的添加方法,就会发现,结果插入了两条数据,一条是import.sql中的,一条是测试方法中的,显然import.sql中的先执行,因为在hibernate启动时就执行了