java访问数据库最直接的方式便是JDBC，这里我们以Mysql数据库为例，来谈谈Java访问数据库上的演进，先建立一个数据库hib_test，然后建立一个用户表t_user，有三个字段，id，name，password：
1 create table `hib_test`.`t_user`( 2 `id` BIGINT not null auto_increment, 3 `name` VARCHAR ( 20 ) not null unique , 4 `password` VARCHAR ( 20 ) not null , 5 primary key (`id`) 6 ); 7 8 create unique index ` PRIMARY ` on `hib_test`.`t_user`(`id`); 9 create unique index `name` on `hib_test`.`t_user`(`name`);接着建立与表对应的域对象TUser：
1 package org.fn.dao; 2 3 /** 4 * TUser entity. @author MyEclipse Persistence Tools 5 */ 6 7 public class TUser implements java.io.Serializable { 8 9 // Fields 10 11 /** 12 * 13 */ 14 private static final long serialVersionUID = 1L ; 15 private Long id; 16 private String name; 17 private String password; 18 19 // Constructors 20 21 /** default constructor */ 22 public TUser() { 23 } 24 25 /** full constructor */ 26 public TUser(String name, String password) { 27 this .name = name; 28 this .password = password; 29 } 30 31 // Property accessors 32 33 public Long getId() { 34 return this .id; 35 } 36 37 public void setId(Long id) { 38 this .id = id; 39 } 40 41 public String getName() { 42 return this .name; 43 } 44 45 public void setName(String name) { 46 this .name = name; 47 } 48 49 public String getPassword() { 50 return this .password; 51 } 52 53 public void setPassword(String password) { 54 this .password = password; 55 } 56 57 }这要的操作便是insert和select
1.jdbc带c3p0数据源操作
1 package org.fn; 2 3 import java.beans.PropertyVetoException; 4 import java.sql.Connection; 5 import java.sql.PreparedStatement; 6 import java.sql.ResultSet; 7 import java.sql.SQLException; 8 9 import javax.sql.DataSource; 10 11 import com.mchange.v2.c3p0.ComboPooledDataSource; 12 13 public class DataSourceTest { 14 15 /** 16 * @param args 17 * @throws PropertyVetoException 18 * @throws SQLException 19 */ 20 public static void main(String[] args) throws PropertyVetoException, SQLException { 21 // TODO Auto-generated method stub 22 ComboPooledDataSource cpds = new ComboPooledDataSource(); 23 cpds.setDriverClass( " com.mysql.jdbc.Driver " ); // loads the jdbc driver 24 cpds.setJdbcUrl( " jdbc:mysql://localhost:3306/hib_test " ); 25 cpds.setUser( " root " ); 26 cpds.setPassword( " root " ); 27 28 DataSource dataSource = cpds; 29 30 Connection conn = dataSource.getConnection(); 31 PreparedStatement pstmt = conn.prepareStatement( " select id, name, password from t_user " ); 32 ResultSet rs = pstmt.executeQuery(); 33 while (rs.next()) { 34 System.out.println(rs.getLong( 1 ) + " : " + rs.getString( 2 ) + " : " + rs.getString( 3 )); 35 36 } 37 rs.close(); 38 pstmt.close(); 39 conn.close(); 40 } 41 42 }2.hibernate数据库操作，其中两个配置文件如下：
TUser.hbm.xml：
1 <? xml version="1.0" encoding="utf-8" ?> 2 <! DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 3 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" > 4 <!-- 5 Mapping file autogenerated by MyEclipse Persistence Tools 6 --> 7 < hibernate-mapping > 8 < class name ="org.fn.dao.TUser" table ="t_user" catalog ="hib_test" > 9 < id name ="id" type ="java.lang.Long" > 10 < column name ="id" /> 11 < generator class ="native" /> 12 </ id > 13 < property name ="name" type ="java.lang.String" > 14 < column name ="name" length ="20" not-null ="true" unique ="true" /> 15 </ property > 16 < property name ="password" type ="java.lang.String" > 17 < column name ="password" length ="20" not-null ="true" /> 18 </ property > 19 </ class > 20 </ hibernate-mapping >hibernate.cfg.xml：
1 <? 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 6 <!-- Generated by MyEclipse Hibernate Tools. --> 7 < hibernate-configuration > 8 9 < session-factory > 10 < property name ="dialect" > 11 org.hibernate.dialect.MySQLDialect 12 </ property > 13 < property name ="connection.url" > 14 jdbc:mysql://localhost:3306/hib_test 15 </ property > 16 < property name ="connection.username" > root </ property > 17 < property name ="connection.password" > root </ property > 18 < property name ="connection.driver_class" > 19 com.mysql.jdbc.Driver 20 </ property > 21 < property name ="show_sql" > true </ property > 22 < property name ="format_sql" > true </ property > 23 < property name ="c3p0.min_size" > 1 </ property > 24 < mapping resource ="org/fn/dao/TUser.hbm.xml" /> 25 26 </ session-factory > 27 28 </ hibernate-configuration > 1 package org.fn; 2 3 import java.util.List; 4 5 import hibernate.HibernateSessionFactory; 6 7 import org.fn.dao.TUser; 8 import org.hibernate.Query; 9 import org.hibernate.Session; 10 import org.hibernate.Transaction; 11 12 public class TUserOp { 13 14 public static void main(String[] args) { 15 // save(); 16 find(); 17 } 18 19 /** 20 * 21 */ 22 public static void find() { 23 Session session = HibernateSessionFactory.getSession(); 24 Transaction tx = session.beginTransaction(); 25 26 Query query = session.createQuery( " from TUser " ); 27 List < TUser > list = query.list(); 28 29 for (TUser user : list) { 30 System.out.println(user.getId() + " : " + user.getName() + " : " + user.getPassword()); 31 } 32 33 tx.commit(); 34 session.close(); 35 } 36 37 public static void save() { 38 Session session = HibernateSessionFactory.getSession(); 39 Transaction tx = session.beginTransaction(); 40 41 TUser user = new TUser(); 42 user.setName( " fnszb7 " ); 43 user.setPassword( " 1234 " ); 44 45 Long id = (Long) session.save(user); 46 System.out.println(id); 47 48 user.setPassword( " 4321 " ); 49 50 tx.commit(); 51 session.close(); 52 } 53 }3。通过spring的bean容器，和HibernateDaoSupport 与 HibernateTemplate操作数据库，配置文件如下：
applicationContext.xml：
1 <? xml version="1.0" encoding="UTF-8" ?> 2 < beans xmlns ="http://www.springframework.org/schema/beans" 3 xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" xmlns:p ="http://www.springframework.org/schema/p" 4 xsi:schemaLocation ="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd" > 5 6 7 < bean id ="sessionFactory" 8 class ="org.springframework.orm.hibernate3.LocalSessionFactoryBean" > 9 <!-- 10 <property name="configLocation" value="file:src/hibernate.cfg.xml"> 11 --> 12 < property name ="configLocation" value ="hibernate.cfg.xml" > 13 </ property > 14 </ bean > 15 </ beans >UserDao（进程HibernateDaoSupport）：
1 package org.fn; 2 3 import java.util.List; 4 5 import org.hibernate.SessionFactory; 6 import org.springframework.context.ApplicationContext; 7 import org.springframework.context.support.ClassPathXmlApplicationContext; 8 import org.springframework.orm.hibernate3.HibernateTemplate; 9 import org.springframework.orm.hibernate3.support.HibernateDaoSupport; 10 11 public class UserDao extends HibernateDaoSupport { 12 public List find(String queryString) { 13 ApplicationContext ctx = new ClassPathXmlApplicationContext( " applicationContext.xml " ); 14 SessionFactory sf = (SessionFactory) ctx.getBean( " sessionFactory " ); 15 super .setSessionFactory(sf); 16 HibernateTemplate ht = super .getHibernateTemplate(); 17 return ht.find(queryString); 18 } 19 } 1 package org.fn; 2 3 import java.util.List; 4 5 import org.fn.dao.TUser; 6 7 public class SpringOp { 8 9 /** 10 * @param args 11 */ 12 public static void main(String[] args) { 13 // TODO Auto-generated method stub 14 // ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml"); 15 // SessionFactory sf = (SessionFactory) ctx.getBean("sessionFactory"); 16 17 // HibernateTemplate ht = new HibernateTemplate(sf); 18 UserDao userDao = new UserDao(); 19 List < TUser > list = userDao.find( " from TUser " ); 20 21 for (TUser user : list) { 22 System.out.println(user.getId() + " : " + user.getName() + " : " + user.getPassword()); 23 } 24 } 25 26 }转载于:https://www.cnblogs.com/nysanier/archive/2011/05/04/2036931.html
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