Hibernate环境搭建

其实去年就开始用Hibernate，但是一直感觉没有系统的开始学过Hibernate，于是准备花一个月的功夫准备学一下Hibernate。

1.使用maven管理依赖的jar包。

maven的pom文件大概就是这样的

<properties>
		<junit.version>4.10</junit.version>
		<spring.version>4.2.0.RELEASE</spring.version>
		<hibernate.version>5.0.0.Final</hibernate.version>
		<fileupload.version>1.3</fileupload.version>
	</properties>
	<dependencies>

		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>5.1.39</version>
		</dependency>
		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-core</artifactId>
			<version>${hibernate.version}</version>
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>jstl</artifactId>
			<version>1.2</version>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-c3p0</artifactId>
			<version>${hibernate.version}</version>
		</dependency>
		<dependency>
			<groupId>org.javassist</groupId>
			<artifactId>javassist</artifactId>
			<version>3.20.0-GA</version>
		</dependency>
	</dependencies>

 

2.在src的根目录下设置好hibernate的配置文件hibernate.cfg.xml

配置方式大概如下

<session-factory>
		<!-- Database connection settings  用的Mysql数据库 -->
		<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="connection.url">jdbc:mysql://数据库地址:数据库端口号/数据库名</property>
		<property name="connection.username">root</property>
		<property name="connection.password">数据库登陆密码</property>

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

		<!-- SQL dialect -->
		<property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</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.internal.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="实体类路径.类名"/>
	</session-factory>

 

3.写一个demo，测试环境是否有配置好。

先建一个实体类

@Entity(name = "DOG")
public class Dog {
	private static final long serialVersionUID = 7219216851705947642L;
	@Id
	@GeneratedValue(strategy = GenerationType.TABLE, generator = "seq_table")
	@TableGenerator(name = "seq_table", 
					table = "seq_table", 
					pkColumnName = "PK_NAME", 
					pkColumnValue = "DOG", 
					valueColumnName = "TABLE_ID", allocationSize = 1,initialValue=1000)
	private Long id;

	@Column(name = "DOG_NAME", nullable = false, unique = true, length = 1000)
	private String name;

	@Column(name = "DOG_AGE", length = 2)
	private int age;

	public Long getId() {
		return id;
	}

	public void setId(Long 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) {
		if (age > 100 || age < 1) {
			this.age = 1;
		} else {
			this.age = age;
		}
	}

	public void say() {
		// TODO Auto-generated method stub
		System.out.println("汪  汪  汪");
	}

	@Override
	public String toString() {
		return "Dog [id=" + id + ", name=" + name + ", age=" + age + "]";
	}
}

 

写一个验证的demo

public class HibernateUtil {
	private static final SessionFactory SESSION_FACTORY = buildSessionFactory();
//采用单例模式获得session
	private static SessionFactory buildSessionFactory() {
		try {
			return new Configuration().configure().buildSessionFactory();
		} catch (Throwable ex) {
			System.err.println("Initial SessionFactory creation failed." + ex);
			throw new ExceptionInInitializerError(ex);
		}
	}

	public static SessionFactory getSessionFactory() {
		return SESSION_FACTORY;
	}
}

public class EventManager {

	public static void main(String[] args) {

		EventManager manager = new EventManager();
		
		Dog dog = new Dog();
		dog.setAge(10);
		dog.setName("heshi");
		manager.save(dog);
		HibernateUtil.getSessionFactory().close();
	}

	
	public void save(Object object){
		Session session = HibernateUtil.getSessionFactory().getCurrentSession();
		session.beginTransaction();
		if(null != object){
			session.save(object);
		}
		session.getTransaction().commit();
	}
}

数据库里面成功的创建的DOG表，且有一条记录才算成功啦。