在Hibernate中开启日志
作者：chszs，转载需注明。博客主页：
在项目中，如果要排查故障，找出Bug，，离不开日志信息。那么在Hibernate项目中如何开启日志输出呢？本文讲述如何在Hibernate中开启日志，以及Hibernate的日志级别。
一、项目开发环境
具体以一个示例项目为例，我们的项目使用了：
Maven 3.2.3Hibernate 5.0.0.CR1 RELEASEEclipse IDE，版本为Luna 4.4.1二、依赖关系
示例项目使用了以下的开源库，包括： 1. hibernate-coreORM持久化的核心库 2. mysql-connector-javaMySQL的JDBC驱动包 3. slf4j-api供Hibernate使用的简单日志Facade 4. slf4j-log4j12Hibernate使用的日志输出库 5. javassistHibernate使用的Java字节码操作库
Hibernate依赖于抽象日志框架SLF4J，使用SLF4J后，可以选择多种日志输出框架。如果项目未绑定任何日志输出框架，那么它是没有任何输出的。故本示例项目绑定了Log4j作为日志输出框架。
三、配置Log4j
在项目的类路径下，创建log4j.properties文件，内容如下：
# Root logger optionlog4j.rootLogger=INFO, consolelog4j.logger.com.ch.demo=INFO, console# Direct log messages to consolelog4j.appender.console=org.apache.log4j.ConsoleAppenderlog4j.appender.console.Target=System.outlog4j.appender.console.layout=org.apache.log4j.PatternLayoutlog4j.appender.console.layout.ConversionPattern=%d{HH:mm}| %p | %F %L | %m%n# direct messages to file hibernate.loglog4j.logger.org.hibernate=DEBUG, hibernatelog4j.appender.hibernate=org.apache.log4j.RollingFileAppenderlog4j.appender.hibernate.File=hibernate.loglog4j.appender.hibernate.layout=org.apache.log4j.PatternLayoutlog4j.appender.hibernate.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %5p %c{1}:%L – %m%n
上面的log4j.properties配置文件中，我们指定所有的Hibernate的具体信息输出类别为hibernate.log。它用于org.hibernate包。如果只想输出部分Hibernate类别的信息，那么需要对指定类别进行配置。
Hibernate主要的类别如下：
1）org.hibernate.SQL日志输出所有Hibernate执行的SQL DML语句
2）org.hibernate.type日志输出所有的JDBC参数
3）org.hibernate.transaction日志输出所有活动相关的事务
4）org.hibernate.jdbc日志输出所有的JDBC资源采集
5）org.hibernate.tool.hbm2ddl日志输出所有Hibernate执行的SQL DDL语句
6）org.hibernate日志输出所有的Hibernate信息
如果指定日志输出类别为org.hibernate.SQL，那么将会输出SQL语句。但是，还有一种更简单的查看SQL语句的方法，只需简单地设置show_sql参数为true。
四、Hibernate日志示例1、创建实体Bean：Orderpackage com.ch.demo.hibernate;import java.util.Date;public class Order {private Long orderId;private String orderNbr;private Date orderDate;private String orderDesc;private Long orderQty;public Order() {}public Order(String orderNbr) {this.orderNbr = orderNbr;}public Long getOrderId() {return orderId;}private void setOrderId(Long orderId) {this.orderId = orderId;}public Date getOrderDate() {return orderDate;}public void setOrderDate(Date orderDate) {this.orderDate = orderDate;}public String getOrderDesc() {return orderDesc;}public void setOrderDesc(String orderDesc) {this.orderDesc = orderDesc;}public Long getOrderQty() {return orderQty;}public void setOrderQty(Long orderQty) {this.orderQty = orderQty;}public String toString() {return “Order: nbr[” + orderNbr + “] date [” + orderDate + “] desc[“+ orderDesc + “] qty[” + orderQty + “]”;}}2、创建ORM映射文件：orders.hbm.xml<!DOCTYPE hibernate-mappingPUBLIC “-//Hibernate/Hibernate Mapping DTD 3.0//EN””http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd”><hibernate-mapping package=”com.ch.demo.hibernate”><class table=”orders”><id column=”order_id”><generator /></id><property column=”order_nbr” type=”string” length=”30″ access=”field”/><property column=”order_desc” type=”string”length=”60″ /><property type=”timestamp” column=”order_date”/><property column=”qty” type=”long” /></class></hibernate-mapping>3、操作数据库的示例代码：HibernateLoggingExample.javapackage com.ch.demo.hibernate;import java.io.IOException;import java.util.Date;import java.util.List;import org.hibernate.MappingException;import org.hibernate.Query;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;public class HibernateLoggingExample {public static void main(String[] args) throws MappingException, IOException {Configuration configuration = new Configuration().configure();SessionFactory sessionFactory = configuration.buildSessionFactory();Session session = sessionFactory.getCurrentSession();Transaction tx = session.getTransaction();tx.begin();Query query = session.createQuery(“from Order where orderNbr=’ORD01′”);List list = query.list();System.out.println(“Orders found: ” + list.size());for(Order order: list) {session.delete(order);System.out.println(“Deleted ” + order);}tx.commit();session = sessionFactory.getCurrentSession();tx = session.getTransaction();tx.begin();Order order = new Order(“ORD01”);order.setOrderDesc(“Laptop”);order.setOrderQty(2L);order.setOrderDate(new Date());session.save(order);tx.commit();session = sessionFactory.getCurrentSession();tx = session.getTransaction();tx.begin();query = session.createQuery(“from Order where orderNbr=’ORD01′”);System.out.println(“List all orders: ” + query.list());tx.commit();sessionFactory.close();}}4、日志输出19:14| DEBUG | IntegratorServiceImpl.java 46 | Adding Integrator [org.hibernate.cfg.beanvalidation.BeanValidationIntegrator].19:14| DEBUG | IntegratorServiceImpl.java 46 | Adding Integrator [org.hibernate.secure.spi.JaccIntegrator].19:14| DEBUG | IntegratorServiceImpl.java 46 | Adding Integrator [org.hibernate.cache.internal.CollectionCacheInvalidator]….19:14| DEBUG | LocalXmlResourceResolver.java 74 | Recognized legacy hibernate-mapping identifier; attempting to resolve on classpath under org/hibernate/19:14| DEBUG | MappingBinder.java 53 | Performing JAXB binding of hbm.xml document : Origin(name=orders.hbm.xml,type=RESOURCE)19:14| DEBUG | BasicTypeRegistry.java 130 | Adding type registration boolean -> org.hibernate.type.BooleanType@55f616cf19:14| DEBUG | BasicTypeRegistry.java 130 | Adding type registration boolean -> org.hibernate.type.BooleanType@55f616cf19:14| DEBUG | BasicTypeRegistry.java 130 | Adding type registration java.lang.Boolean -> org.hibernate.type.BooleanType@55f616cf…19:14| DEBUG | ErrorCounter.java 95 | throwQueryException() : no errors19:14| DEBUG | QueryTranslatorImpl.java 246 | HQL: from com.ch.demo.hibernate.Order where orderNbr=’ORD01’19:14| DEBUG | QueryTranslatorImpl.java 247 | SQL: select order0_.order_id as order_id1_0_, order0_.order_nbr as order_nb2_0_, order0_.order_desc as order_de3_0_, order0_.order_date as order_da4_0_, order0_.qty as qty5_0_ from orders order0_ where order0_.order_nbr=’ORD01’19:14| DEBUG | ErrorCounter.java 95 | throwQueryException() : no errors…19:14| DEBUG | SqlStatementLogger.java 92 | delete from orders where order_id=?Hibernate: delete from orders where order_id=?…19:14| DEBUG | SqlStatementLogger.java 92 | insert into orders (order_nbr, order_desc, order_date, qty) values (?, ?, ?, ?)Hibernate: insert into orders (order_nbr, order_desc, order_date, qty) values (?, ?, ?, ?)
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