介绍Hibernate使用UserType-ClobStringType
-
这里介绍Hibernate使用UserType,UserType就是用户自定义类型,这里的类型指的是除了Hibernate定义的那些类型之外的用户自己定义的。
UserType就是用户自定义类型,这里的类型指的是除了Hibernate定义的那些类型之外的用户自己定义的。
一个实现Hibernate使用UserType接口的 email 类如下(里面的每个方法都是必须实现的接口方法,许多都可以复制粘贴的,不复杂):
- /*
* $HeadURL$
* Copyright (c) 2003-2007 Untangle, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
* NONINFRINGEMENT. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package com.untangle.uvm.type;
import java.io.Serializable;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import org.hibernate.HibernateException;
import org.hibernate.usertype.UserType;
/**
* Hibernate <code>UserType</code> for persisting
* <code>InetAddress</code> objects.
*
* @author <a href="mailto:amread@untangle.com">Aaron Read</a>
* @version 1.0
*/
public class InetAddressUserType implements UserType
{
private static final int[] SQL_TYPES = { Types.VARCHAR };
public int[] sqlTypes() { return SQL_TYPES; }//该类型对应的 sql 类型
public Class<InetAddress> returnedClass() { return InetAddress.class; }
public boolean equals(Object x, Object y) //equals方法,这个就不用多说了吧,肯定是要用户自定义的
{
if (x == y) { return true; }
if (x == null || y == null) { return false; }
return x.equals(y);
}
public Object deepCopy(Object value) { return value; } // 完全复制的方法,由于是用户自己定义的类型//所以hibernate并不知道要如何来复制这个类,需要用户自己定义
public boolean isMutable() { return false; } // 表示本类型实例是否可变,一般是不可变
- /** *//**//*
- 这才是重头戏!nullSafeGet 和nullSafeSet 是核心所在,对数据的后期处理都在这两个方法里面
- nullSafeGet 是读取的方法
- owner 目前没用到过。
- names 是对应的数据库列名,UserType是可以对应多个列的
- */
public Object nullSafeGet(ResultSet rs, String[] names, Object owner)
throws HibernateException, SQLException
{
String name = rs.getString(names[0]);
if (rs.wasNull()) { return null; }
try {
return InetAddress.getByName(name);
} catch (UnknownHostException exn) {
throw new HibernateException(exn);
}
}
- /**//*
- 保存的方法
- index 是那个 PreparedStatement 的参数序号,一般来说不用管直接往下传
- value 就是要保存的数据,在这边是一个保存着 email 列表的 List
- */
public void nullSafeSet(PreparedStatement ps, Object v, int i)
throws HibernateException, SQLException
{
if (null == v) {
ps.setNull(i, Types.VARCHAR);
} else {
InetAddress addr = (InetAddress)v;
ps.setString(i, addr.getHostAddress());
}
}
public Object replace(Object original, Object target, Object owner)
{
return original;
}
public Object assemble(Serializable cached, Object owner)
{
return deepCopy(cached);
}
public Serializable disassemble(Object value)
{
return (Serializable)deepCopy(value);
}
public int hashCode(Object x)
{
return x.hashCode();
}
}
下来是对应pojo类,这个类用了相应的注解
package com.untangle.uvm.logging;
import java.net.InetAddress;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.Transient;
import org.hibernate.annotations.Type;
import com.untangle.uvm.logging.PipelineEvent;
import com.untangle.uvm.logging.SyslogBuilder;
import com.untangle.uvm.logging.SyslogPriority;
import com.untangle.uvm.node.PipelineEndpoints;
/**
* Log event from the denormalized reports.n_cpd_block_events reports table
*
* @author Sebastien Delafond
* @version 1.0
*/
@Entity
@org.hibernate.annotations.Entity(mutable=false)
@Table(name="n_cpd_block_events", schema="reports")
@SuppressWarnings("serial")
public class CpdBlockEventsFromReports extends LogEvent
{
private InetAddress clientAddress;
private InetAddress serverAddress;
private Integer clientPort;
private Integer serverPort;
private Integer clientIntf;
private Integer proto;
@Column(name="client_address")
@Type(type="com.untangle.uvm.type.InetAddressUserType")//自定义的usertype
public InetAddress getClientAddress() { return clientAddress; }
public void setClientAddress(InetAddress clientAddress) { this.clientAddress = clientAddress; }
@Column(name="server_address")
@Type(type="com.untangle.uvm.type.InetAddressUserType")
public InetAddress getServerAddress() { return serverAddress; }
public void setServerAddress(InetAddress serverAddress) { this.serverAddress = serverAddress; }
@Column(name="client_port")
public Integer getClientPort() { return clientPort; }
public void setClientPort(Integer clientPort) { this.clientPort = clientPort; }
@Column(name="server_port")
public Integer getServerPort() { return serverPort; }
public void setServerPort(Integer serverPort) { this.serverPort = serverPort; }
@Column(name="proto")
public Integer getProto() { return proto; }
public void setProto(Integer proto) { this.proto = proto; }
@Column(name="client_intf")
public Integer getClientIntf() { return clientIntf; }
public void setClientIntf(Integer clientIntf) { this.clientIntf = clientIntf; }
public void appendSyslog(SyslogBuilder sb) // FIXME: not called for now
{
}
@Transient
public String getSyslogId()
{
return ""; // FIMXE ?
}
@Transient
public SyslogPriority getSyslogPriority()
{
// FIXME
return SyslogPriority.INFORMATIONAL;
}
}