环境
- Eclipse
- MySQL
下载Hibernate所需jar包
可到官网下载: 快速通道
下载好后解压，打开压缩包下的lib目录下的require文件夹，这是hibernate的所以来的必须的jar包，copy到Project/WebContent/WEB-INF/lib 目录下，并添加依赖, 没有的自行创建
由于我们需要连接MySQL数据库，将所需的mysql-connector-java-5.0.8-bin.jar引用进去，关于这些jar包，可以在网上搜索。
注意这里我用的是4.2版本的hibernate-core-4.2.1.Final.jar
配置Hibernate.conf.xml
我们需要配置最重要的hibernate配置文件hibernate.cfg.xml以及进行日志处理的log4j.properties属性文件：打开上一步解压后的hibernate文件夹，打开project—>etc文件夹，将该文件夹下的hibernate.cfg.xml和log4j.properties文件拷贝到项目的src文件夹下，打开hibernate.cfg.xml文件，将session-factory标签中的内容替换成如下的内容：
<session-factory>
<!-- MySQL -->
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306?useUnicode=true&characterEncoding=UTF-8</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">dixm</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
<property name="hibernate.show_sql">true</property>
<property name="hibernate.use_sql_comments">true</property>
<property name="hibernate.connection.pool_size">0</property>
<!-- Mappings -->
</session-factory>
自动生成数据库表
创建DDLCreator类
import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
public class DDLCreator {
/**
* @param args
*/
public static void main(String[] args) {
Configuration cfg = new Configuration().configure();
SchemaExport se = new SchemaExport(cfg);
se.drop(true, true); //ɾ
se.create(true, true); //
}
}
创建HibernateUtil类
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
@SuppressWarnings("deprecation")
public class HibernateUtil {
private static SessionFactory sessionFactory;
static {
try {
sessionFactory = new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
// Alternatively, you could look up in JNDI here
return sessionFactory;
}
public static void shutdown() {
// Close caches and connection pools
getSessionFactory().close();
}
public static Session getSession()
{
Session session = sessionFactory.openSession();
return session;
}
public static void beginSession(Session session)
{
session.getTransaction().begin();
}
public static void commitTransaction(Session session)
{
session.getTransaction().commit();
}
public static void rollbackTransaction(Session session)
{
Transaction tx = session.getTransaction();
if (tx.isActive())
tx.rollback();
}
}
创建实体类
如 TVersion
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity //表示实体类
@Table(catalog = "dbcoolweather") //数据库名
public class TVersion {
private long id;
private int version_code;
private String version_name;
private String description;
private String path;
//主键，自增
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public int getVersion_code() {
return version_code;
}
public void setVersion_code(int version_code) {
this.version_code = version_code;
}
public String getVersion_name() {
return version_name;
}
public void setVersion_name(String version_name) {
this.version_name = version_name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
}
在Hibernate.cfg.xml中添加映射关系
<!-- Mappings -->
<mapping class="com.allever.mycoolweather.bean.TVersion"/>
创建数据库
首先在MySQL中手动创建数据库： dbcoolweather
运行DDLCreator类
刷新数据库表，此时，tversion表已经建好了, 有木有很惊讶～～～
对数据库进行增删改查
创建VersionDAO类
import java.util.List;
import org.hibernate.Query;
import org.hibernate.Session;
import com.allever.mycoolweather.bean.TVersion;
import com.allever.mycoolweather.util.HibernateUtil;
public class VersionDAO {
Session session = null;
boolean commit = false;
public VersionDAO() {
this.session = HibernateUtil.getSession();
commit = true;
HibernateUtil.beginSession(session);
}
public VersionDAO(Session session) {
this.session = session;
commit = false;
}
public void close() {
if (commit == true) {
HibernateUtil.commitTransaction(session);
session.close();
}
}
public Session getSession() {
return session;
}
public TVersion getById(long id) throws Exception {
TVersion d = null;
try {
d = (TVersion) session.get(TVersion.class, id);
} catch (Exception e) {
HibernateUtil.rollbackTransaction(session);
throw e;
}
return d;
}
@SuppressWarnings("unchecked")
public List<TVersion> getByQuery(String conditions, long start,
long limit) throws Exception {
List<TVersion> dl = null;
try {
String hql = "from TVersion";
if ((conditions != null) && (conditions.length() > 0))
hql += " where " + conditions;
Query query = session.createQuery(hql);
if (limit > 0) {
query.setFirstResult((int) start);
query.setMaxResults((int) limit);
}
dl = (List<TVersion>) query.list();
} catch (Exception e) {
HibernateUtil.rollbackTransaction(session);
throw e;
}
return dl;
}
@SuppressWarnings("unchecked")
public List<TVersion> getUpdateVersion(long start,long limit) throws Exception {
List<TVersion> dl = null;
try {
String hql = "from TVersion ORDER BY version_code DESC";
Query query = session.createQuery(hql);
if (limit > 0) {
query.setFirstResult((int) 0);
query.setMaxResults((int) 0);
}
dl = (List<TVersion>) query.list();
} catch (Exception e) {
HibernateUtil.rollbackTransaction(session);
throw e;
}
return dl;
}
public TVersion add(TVersion d) throws Exception {
Long id = null;
try {
id = (Long) session.save(d);
} catch (Exception e) {
HibernateUtil.rollbackTransaction(session);
throw e;
}
return getById(id);
}
public void deleteById(long id) throws Exception {
TVersion d = null;
try {
d = (TVersion) session.get(TVersion.class, id);
if (d != null)
session.delete(d);
} catch (Exception e) {
HibernateUtil.rollbackTransaction(session);
throw e;
}
}
public TVersion update(TVersion d) throws Exception {
try {
session.update(d);
}
catch(RuntimeException e) {
HibernateUtil.rollbackTransaction(session);
throw e;
}
return getById(d.getId());
}
}
各位看函数名就知道要干什么了吧，这里就不哆嗦了
创建VersionTest类进行测试
public class VersionTest {
public static void main(String[] args){
}
}
就是一个普通的JAVA类
初始化DAO
VersionDAO dao = new VersionDAO();
//operation
dao.close();
增加一条记录
try{
TVersion v1 = new TVersion();
v1.setVersion_code(5);
v1.setDescription("第3版");
v1.setVersion_name("1.3");
v1.setPath("/apk/mycoolweather_1.3.apk");
dao.add(v1);
}catch(Exception e){
e.printStackTrace();
}finally{
dao.close();
}
查询一条记录
List<TVersion> list_tversion = new ArrayList<>();
list_tversion = dao.getByQuery("version_code="+ 5, 0, 0);
if(list_tversion.size()>0){
TVersion v = list_tversion.get(0);
v.getVersion_name();
}
查询所有记录
List<TVersion> list_tversion = new ArrayList<>();
// null or ""
list_tversion = dao.getByQuery(null, 0, 0);
for(TVersion tversion: list_tversion){
tversion.getVersion_name();
System.out.println(tversion.getDescription());
}
修改数据
List<TVersion> list_tversion = new ArrayList<>();
list_tversion = dao.getByQuery("version_code="+ 5, 0, 0);
if(list_tversion.size()>0){
TVersion v = list_tversion.get(0);
v.setDescription("new Description");
dao.update(v);
}
删除数据
List<TVersion> list_tversion = new ArrayList<>();
list_tversion = dao.getByQuery("version_code="+ 5, 0, 0);
if(list_tversion.size()>0){
TVersion v = list_tversion.get(0);
v.setDescription("new Description");
dao.deleteById(v.getId());
}
OK,大功告成.
写这篇复习了以前所学知识，下一步，继续学习新版本的知识
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