在Hibernate中开启日志
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：
1. Maven 3.2.3
http://maven.apache.org/
2. Hibernate 5.0.0.CR1 RELEASE
http://hibernate.org/orm/
3. Eclipse IDE，版本为Luna 4.4.1
http://www.eclipse.org/
二、依赖关系
示例项目使用了以下的开源库，包括：
1. hibernate-core
ORM持久化的核心库
2. mysql-connector-java
MySQL的JDBC驱动包
3. slf4j-api
供Hibernate使用的简单日志Facade
4. slf4j-log4j12
Hibernate使用的日志输出库
5. javassist
Hibernate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 option
- log4j.rootLogger=INFO, console
- log4j.logger.com.ch.demo=INFO, console
- # Direct log messages to console
- log4j.appender.console=org.apache.log4j.ConsoleAppender
- log4j.appender.console.Target=System.out
- log4j.appender.console.layout=org.apache.log4j.PatternLayout
- log4j.appender.console.layout.ConversionPattern=%d{HH:mm}| %p | %F %L | %m%n
- # direct messages to file hibernate.log
- log4j.logger.org.hibernate=DEBUG, hibernate
- log4j.appender.hibernate=org.apache.log4j.RollingFileAppender
- log4j.appender.hibernate.File=hibernate.log
- log4j.appender.hibernate.layout=org.apache.log4j.PatternLayout
- log4j.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：Order
- package 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-mapping
- PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
- "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
- <hibernate-mapping package="com.ch.demo.hibernate">
- <class name="com.ch.demo.hibernate.Order" table="orders">
- <id name="orderId" column="order_id">
- <generator class="native" />
- </id>
- <property name="orderNbr" column="order_nbr" type="string" length="30" access="field"/>
- <property name="orderDesc" column="order_desc" type="string"
- length="60" />
- <property name="orderDate" type="timestamp" column="order_date"/>
- <property name="orderQty" column="qty" type="long" />
- </class>
- </hibernate-mapping>
3、操作数据库的示例代码：HibernateLoggingExample.java
- package 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@55f616cf
- 19:14| DEBUG | BasicTypeRegistry.java 130 | Adding type registration boolean -> org.hibernate.type.BooleanType@55f616cf
- 19:14| DEBUG | BasicTypeRegistry.java 130 | Adding type registration java.lang.Boolean -> org.hibernate.type.BooleanType@55f616cf
- ...
- 19:14| DEBUG | ErrorCounter.java 95 | throwQueryException() : no errors
- 19:14| 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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