在Hibernate中开启日志

作者：chszs，转载需注明。博客主页：http://blog.csdn.net/chszs

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 (?, ?, ?, ?)