3.Hibernate入门笔记
Hibernate入门指南笔记
1. 首先下载Hibernate包
Hibernate5.0.7
2. 在MySQL中创建数据库和表
CREATE DATABASE myblog;
USE myblog;
CREATE TABLE IF NOT EXISTS cust_customer(cust_id BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT '用户id',cust_name VARCHAR(32) NOT NULL COMMENT '客户名称(公司名称)',cust_source VARCHAR(32) DEFAULT NULL COMMENT '客户信息来源',cust_industry VARCHAR(32) DEFAULT NULL COMMENT '客户所属行业',cust_level VARCHAR(32) DEFAULT NULL COMMENT '客户级别',cust_phone VARCHAR(64) DEFAULT NULL COMMENT '固定电话',cust_mobile VARCHAR(14) DEFAULT NULL COMMENT '移动电话'
);
复制代码3. 导入数据库驱动包与Hibernate包以及日志记录包
3.1 导入Hibernate包如下
3.2 导入MySQL数据库连接驱动包
mysql-connector-java-5.1.43-bin.jar
3.3 导入日志记录包
在工程目录下面新建一个lib目录将所需要的包拷贝到lib文件夹下
4.在工程的src下创建一个实体，对应于数据库中的cust_customer表
package com.whong;
public class cust_customer {private long cust_id;private String cust_name;private String cust_source;private String cust_industry;private String cust_level;private String cust_phone;private String cust_mobile;public long getCust_id() {return cust_id;}public void setCust_id(long cust_id) {this.cust_id = cust_id;}public String getCust_name() {return cust_name;}public void setCust_name(String cust_name) {this.cust_name = cust_name;}public String getCust_source() {return cust_source;}public void setCust_source(String cust_source) {this.cust_source = cust_source;}public String getCust_industry() {return cust_industry;}public void setCust_industry(String cust_industry) {this.cust_industry = cust_industry;}public String getCust_level() {return cust_level;}public void setCust_level(String cust_level) {this.cust_level = cust_level;}public String getCust_phone() {return cust_phone;}public void setCust_phone(String cust_phone) {this.cust_phone = cust_phone;}public String getCust_mobile() {return cust_mobile;}public void setCust_mobile(String cust_mobile) {this.cust_mobile = cust_mobile;}
}
复制代码5.创建映射文件
映射文件是将刚才的实体cust_customer映射到数据库中的 因为安装了hibernate的插件，所以在这里可以直接选择创建hbm文件，不需要手动去配置
"1.0"?>
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
"com.whong.cust_customer" table="CUST_CUSTOMER">"cust_id" type="long">"CUST_ID" />"assigned" /> "cust_name" type="java.lang.String">"CUST_NAME" /> "cust_source" type="java.lang.String">"CUST_SOURCE" /> "cust_industry" type="java.lang.String">"CUST_INDUSTRY" /> "cust_level" type="java.lang.String">"CUST_LEVEL" /> "cust_phone" type="java.lang.String">"CUST_PHONE" /> "cust_mobile" type="java.lang.String">"CUST_MOBILE" />
6.创建Hibernate的核心配置文件
在第五步骤中的映射文件反应的是持久化类和数据库表的映射信息，而Hibernate的配置文件则主要是用来配置数据库连接以及Hibernate运行时所需要的各个属性的值，在src文件夹下创建cfg类型的文件
?usessl=true 完整的url为 jdbc:mysql://localhost:3306/myblog?usessl=true 7.编写一个测试代码
测试代码如下所示
package com.testPackage;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import com.whong.cust_customer;public class testHibernate {public static void main(String[] args) {// TODO Auto-generated method stubConfiguration configuration = new Configuration().configure();SessionFactory sessionFactory = configuration.buildSessionFactory();Session session = sessionFactory.openSession();Transaction transaction = session.beginTransaction();cust_customer cust_customer = new cust_customer();cust_customer.setCust_name("伟鸿");cust_customer.setCust_phone("18*******969");session.save(cust_customer);transaction.commit();session.close();}
}
复制代码8.试运行
如果这个时候试运行会报有如下的错误
log4j:WARN No appenders could be found for logger (org.jboss.logging).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Exception in thread "main" org.hibernate.MappingException: Unknown entity: com.whong.cust_customerat org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:781)at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1520)at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:100)at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:679)at org.hibernate.internal.SessionImpl.save(SessionImpl.java:671)at org.hibernate.internal.SessionImpl.save(SessionImpl.java:666)at com.testPackage.testHibernate.main(testHibernate.java:21)
复制代码8.1解决方案
这里最主要的问题就是log日志文件的问题 解决方式是需要添加一个有关日志的配置文件，具体可以看一下这个链接的文章log4j WARN 和 SLF4J WARN 解决办法 在src目录下添加log4j.properties配置文件
hadoop.root.logger=DEBUG, console
log4j.rootLogger=INFO, 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{yy/MM/dd HH:mm:ss} %p %c{2}: %m%n
复制代码8.2实体映射错误解决方式
再次运行会报如下的错误
Exception in thread "main" org.hibernate.MappingException: Unknown entity: com.whong.cust_customerat org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:781)at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1520)at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:100)at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:679)at org.hibernate.internal.SessionImpl.save(SessionImpl.java:671)at org.hibernate.internal.SessionImpl.save(SessionImpl.java:666)at com.testPackage.testHibernate.main(testHibernate.java:21)
复制代码这个问题时因为核心配置文件cfg和实体映射文件hbm之间没有对应起来，所以找不到那个cust_customer实体 解决方式如下 拷贝hbm文件的路径
再次运行的到正确的结果 并打印如下的一些日志记录
18/02/28 16:21:05 INFO hibernate.Version: HHH000412: Hibernate Core {5.0.7.Final}
18/02/28 16:21:05 INFO cfg.Environment: HHH000206: hibernate.properties not found
18/02/28 16:21:05 INFO cfg.Environment: HHH000021: Bytecode provider name : javassist
18/02/28 16:21:05 INFO common.Version: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
18/02/28 16:21:05 WARN orm.deprecation: HHH90000012: Recognized obsolete hibernate namespace http://hibernate.sourceforge.net/hibernate-mapping. Use namespace http://www.hibernate.org/dtd/hibernate-mapping instead. Support for obsolete DTD/XSD namespaces may be removed at any time.
18/02/28 16:21:06 WARN orm.connections: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
18/02/28 16:21:06 INFO orm.connections: HHH10001005: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/myblog?useSSL=true]
18/02/28 16:21:06 INFO orm.connections: HHH10001001: Connection properties: {user=root, password=****}
18/02/28 16:21:06 INFO orm.connections: HHH10001003: Autocommit mode: false
18/02/28 16:21:06 INFO internal.DriverManagerConnectionProviderImpl: HHH000115: Hibernate connection pool size: 20 (min=1)
18/02/28 16:21:07 INFO dialect.Dialect: HHH000400: Using dialect: org.hibernate.dialect.MySQL5Dialect
复制代码再数据库中查询cust_customer表也是可以查询到这一条记录的 至此hibernate的入门配置笔记完毕
WiHongNoteBook
转载于:https://juejin.im/post/5c2728ce51882551b7280c8f
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