hibernate 二级缓存「建议收藏」

package com.atguigu.hibernate.entities;

import java.util.HashSet;
import java.util.Set;

public class Department {

	private Integer id;
	private String name;
	
	private Set<Employee> emps = new HashSet<>();

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public Set<Employee> getEmps() {
		return emps;
	}

	public void setEmps(Set<Employee> emps) {
		this.emps = emps;
	}

	@Override
	public String toString() {
		return "Department [id=" + id + "]";
	}
	
}

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

    <class name="com.atguigu.hibernate.entities.Department" table="GG_DEPARTMENT">
        
        <id name="id" type="java.lang.Integer">
            <column name="ID" />
            <generator class="native" />
        </id>
    
        <property name="name" type="java.lang.String">
            <column name="NAME" />
        </property>
        
        <set name="emps" table="GG_EMPLOYEE" inverse="true" lazy="true">
            <key>
                <column name="DEPT_ID" />
            </key>
            <one-to-many class="com.atguigu.hibernate.entities.Employee" />
        </set>
        
    </class>
</hibernate-mapping>

package com.atguigu.hibernate.entities;

public class Employee {

	private Integer id;
	private String name;
	private float salary;
	private String email;
	
	private Department dept;

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public float getSalary() {
		return salary;
	}

	public void setSalary(float salary) {
		this.salary = salary;
	}

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public Department getDept() {
		return dept;
	}

	public void setDept(Department dept) {
		this.dept = dept;
	}

	@Override
	public String toString() {
		return "Employee [id=" + id + "]";
	}

	public Employee(String email, float salary, Department dept) {
		super();
		this.salary = salary;
		this.email = email;
		this.dept = dept;
	}
	
	public Employee() {
		// TODO Auto-generated constructor stub
	}
	
}

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

    <class name="com.atguigu.hibernate.entities.Employee" table="GG_EMPLOYEE">
    	
    	<!--  
    	<cache usage="read-write"/>
    	-->
    		
        <id name="id" type="java.lang.Integer">
            <column name="ID" />
            <generator class="native" />
        </id>
    
        <property name="name" type="java.lang.String">
            <column name="NAME" />
        </property>
        
        <property name="salary" type="float">
            <column name="SALARY" />
        </property>
        
        <property name="email" type="java.lang.String">
            <column name="EMAIL" />
        </property>
        
        <many-to-one name="dept" class="com.atguigu.hibernate.entities.Department">
            <column name="DEPT_ID" />
        </many-to-one>
        
    </class>
    
    <query name="salaryEmps"><![CDATA[FROM Employee e WHERE e.salary > :minSal AND e.salary < :maxSal]]></query>
    
</hibernate-mapping>

package com.atguigu.hibernate.test;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Conjunction;
import org.hibernate.criterion.Disjunction;
import org.hibernate.criterion.MatchMode;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Projections;
import org.hibernate.criterion.Restrictions;
import org.hibernate.jdbc.Work;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.atguigu.hibernate.dao.DepartmentDao;
import com.atguigu.hibernate.entities.Department;
import com.atguigu.hibernate.entities.Employee;
import com.atguigu.hibernate.hibernate.HibernateUtils;

public class HibernateTest {

	private SessionFactory sessionFactory;
	private Session session;
	private Transaction transaction;
	
	@Before
	public void init(){
		Configuration configuration = new Configuration().configure();
		ServiceRegistry serviceRegistry = 
				new ServiceRegistryBuilder().applySettings(configuration.getProperties())
				                            .buildServiceRegistry();
		sessionFactory = configuration.buildSessionFactory(serviceRegistry);
		
		session = sessionFactory.openSession();
		transaction = session.beginTransaction();
	}
	
	@After
	public void destroy(){
		transaction.commit();
		session.close();
		sessionFactory.close();
	}
	
	@Test
	public void testBatch(){
		session.doWork(new Work() {			
			@Override
			public void execute(Connection connection) throws SQLException {
				//通过 JDBC 原生的 API 进行操作, 效率最高, 速度最快!
			}
		});
	}
	
	@Test
	public void testManageSession(){
		
		//获取 Session
		//开启事务
		Session session = HibernateUtils.getInstance().getSession();
		System.out.println("-->" + session.hashCode());
		Transaction transaction = session.beginTransaction();
		
		DepartmentDao departmentDao = new DepartmentDao();
		
		Department dept = new Department();
		dept.setName("ATGUIGU");
		
		departmentDao.save(dept);
		departmentDao.save(dept);
		departmentDao.save(dept);
		
		//若 Session 是由 thread 来管理的, 则在提交或回滚事务时, 已经关闭 Session 了. 
		transaction.commit();
		System.out.println(session.isOpen()); 
	}
	
	@Test
	public void testQueryIterate(){
		Department dept = (Department) session.get(Department.class, 70);
		System.out.println(dept.getName());
		System.out.println(dept.getEmps().size()); 
		
		Query query = session.createQuery("FROM Employee e WHERE e.dept.id = 80");
//		List<Employee> emps = query.list();
//		System.out.println(emps.size()); 
		
		Iterator<Employee> empIt = query.iterate();
		while(empIt.hasNext()){
			System.out.println(empIt.next().getName()); 
		}
	}
	
	@Test
	public void testUpdateTimeStampCache(){
		Query query = session.createQuery("FROM Employee");
		query.setCacheable(true);
		
		List<Employee> emps = query.list();
		System.out.println(emps.size());
		
		Employee employee = (Employee) session.get(Employee.class, 100);
		employee.setSalary(30000);
		
		emps = query.list();
		System.out.println(emps.size());
	}
	
	@Test
	public void testQueryCache(){
		Query query = session.createQuery("FROM Employee");
		query.setCacheable(true);
		
		List<Employee> emps = query.list();
		System.out.println(emps.size());
		
		emps = query.list();
		System.out.println(emps.size());
		
		Criteria criteria = session.createCriteria(Employee.class);
		criteria.setCacheable(true);
	}
	
	@Test
	public void testCollectionSecondLevelCache(){
		Department dept = (Department) session.get(Department.class, 80);
		System.out.println(dept.getName());
		System.out.println(dept.getEmps().size()); 
		
		transaction.commit();
		session.close();
		
		session = sessionFactory.openSession();
		transaction = session.beginTransaction();
		
		Department dept2 = (Department) session.get(Department.class, 80);
		System.out.println(dept2.getName());
		System.out.println(dept2.getEmps().size()); 
	}
	
	@Test
	public void testHibernateSecondLevelCache(){
		Employee employee = (Employee) session.get(Employee.class, 100);
		System.out.println(employee.getName()); 
		
		transaction.commit();
		session.close();
		
		session = sessionFactory.openSession();
		transaction = session.beginTransaction();
		
		Employee employee2 = (Employee) session.get(Employee.class, 100);
		System.out.println(employee2.getName()); 
	}
	
}

<?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>
    
    	<!-- Hibernate 连接数据库的基本信息 -->
    	<property name="connection.username">scott</property>
    	<property name="connection.password">java</property>
    	<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
    	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:orcl</property>

		<!-- Hibernate 的基本配置 -->
		<!-- Hibernate 使用的数据库方言 -->
		<property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
	
		<!-- 运行时是否打印 SQL -->
    	<property name="show_sql">true</property>
    
    	<!-- 运行时是否格式化 SQL -->
    	<property name="format_sql">true</property>
    
    	<!-- 生成数据表的策略 -->
    	<property name="hbm2ddl.auto">update</property>
    	
    	<!-- 设置 Hibernate 的事务隔离级别 -->
    	<property name="connection.isolation">2</property>
    	
    	<!-- 删除对象后, 使其 OID 置为 null -->
    	<property name="use_identifier_rollback">true</property>
    	
    	<!-- 配置 C3P0 数据源 -->
    	<!--  
    	<property name="hibernate.c3p0.max_size">10</property>
    	<property name="hibernate.c3p0.min_size">5</property>
    	<property name="c3p0.acquire_increment">2</property>
    	
    	<property name="c3p0.idle_test_period">2000</property>
    	<property name="c3p0.timeout">2000</property>
    	
    	<property name="c3p0.max_statements">10</property>
    	-->
    	
    	<!-- 设定 JDBC 的 Statement 读取数据的时候每次从数据库中取出的记录条数 -->
    	<property name="hibernate.jdbc.fetch_size">100</property>
    	
    	<!-- 设定对数据库进行批量删除，批量更新和批量插入的时候的批次大小 -->
    	<property name="jdbc.batch_size">30</property>
    	
    	<!-- 启用二级缓存 -->
		<property name="cache.use_second_level_cache">true</property>
    	
    	<!-- 配置使用的二级缓存的产品 -->
    	<property name="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</property>
    	
    	<!-- 配置启用查询缓存 -->
    	<property name="cache.use_query_cache">true</property>
    	
    	<!-- 配置管理 Session 的方式 -->
    	<property name="current_session_context_class">thread</property>
    	
    	<!-- 需要关联的 hibernate 映射文件 .hbm.xml -->
		<mapping resource="com/atguigu/hibernate/entities/Department.hbm.xml"/>
		<mapping resource="com/atguigu/hibernate/entities/Employee.hbm.xml"/>
		
		<class-cache usage="read-write" class="com.atguigu.hibernate.entities.Employee"/>
		<class-cache usage="read-write" class="com.atguigu.hibernate.entities.Department"/>
		<collection-cache usage="read-write" collection="com.atguigu.hibernate.entities.Department.emps"/>
    </session-factory>
</hibernate-configuration>

<ehcache>

    <!-- Sets the path to the directory where cache .data files are created.

         If the path is a Java System Property it is replaced by
         its value in the running VM.

         The following properties are translated:
         user.home - User's home directory
         user.dir - User's current working directory
         java.io.tmpdir - Default temp file path -->
    <!--  
    	指定一个目录：当 EHCache 需要 把数据写到硬盘上时, 将把数据写到这个目录下.
    -->     
    <diskStore path="d:\\tempDirectory"/>


    <!--Default Cache configuration. These will applied to caches programmatically created through
        the CacheManager.

        The following attributes are required for defaultCache:

        maxInMemory       - Sets the maximum number of objects that will be created in memory
        eternal           - Sets whether elements are eternal. If eternal,  timeouts are ignored and the element
                            is never expired.
        timeToIdleSeconds - Sets the time to idle for an element before it expires. Is only used
                            if the element is not eternal. Idle time is now - last accessed time
        timeToLiveSeconds - Sets the time to live for an element before it expires. Is only used
                            if the element is not eternal. TTL is now - creation time
        overflowToDisk    - Sets whether elements can overflow to disk when the in-memory cache
                            has reached the maxInMemory limit.

        -->
    <!--  
    	设置缓存的默认数据过期策略 
    -->    
    <defaultCache
        maxElementsInMemory="10000"
        eternal="false"
        timeToIdleSeconds="120"
        timeToLiveSeconds="120"
        overflowToDisk="true"
        />

   	<!--  
   		设定具体的命名缓存的数据过期策略。每个命名缓存代表一个缓存区域
   		缓存区域(region)：一个具有名称的缓存块，可以给每一个缓存块设置不同的缓存策略。
   		如果没有设置任何的缓存区域，则所有被缓存的对象，都将使用默认的缓存策略。即：<defaultCache.../>
   		Hibernate 在不同的缓存区域保存不同的类/集合。
			对于类而言，区域的名称是类名。如:com.atguigu.domain.Customer
			对于集合而言，区域的名称是类名加属性名。如com.atguigu.domain.Customer.orders
   	-->
   	<!--  
   		name: 设置缓存的名字,它的取值为类的全限定名或类的集合的名字 
		maxElementsInMemory: 设置基于内存的缓存中可存放的对象最大数目 
		
		eternal: 设置对象是否为永久的, true表示永不过期,
		此时将忽略timeToIdleSeconds 和 timeToLiveSeconds属性; 默认值是false 
		timeToIdleSeconds:设置对象空闲最长时间,以秒为单位, 超过这个时间,对象过期。
		当对象过期时,EHCache会把它从缓存中清除。如果此值为0,表示对象可以无限期地处于空闲状态。 
		timeToLiveSeconds:设置对象生存最长时间,超过这个时间,对象过期。
		如果此值为0,表示对象可以无限期地存在于缓存中. 该属性值必须大于或等于 timeToIdleSeconds 属性值 
		
		overflowToDisk:设置基于内存的缓存中的对象数目达到上限后,是否把溢出的对象写到基于硬盘的缓存中 
   	-->
    <cache name="com.atguigu.hibernate.entities.Employee"
        maxElementsInMemory="1"
        eternal="false"
        timeToIdleSeconds="300"
        timeToLiveSeconds="600"
        overflowToDisk="true"
        />

    <cache name="com.atguigu.hibernate.entities.Department.emps"
        maxElementsInMemory="1000"
        eternal="true"
        timeToIdleSeconds="0"
        timeToLiveSeconds="0"
        overflowToDisk="false"
        />

</ehcache>