hibernate处理BLOB例子

1.在mysql建立表

    create table `test`.`testblob`(
        `id` int not null auto_increment,
       `image` blob,
        primary key (`id`)
    );

    create unique index `PRIMARY` on `test`.`testblob`(`id`);

2.在eclipse中建立工程,并导入hibernate包.生成hibernate.cfg.xml 配置文件和HibernateSessionFactory.java

 

package org.myhibernate;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;

/** *//**
 * Configures and provides access to Hibernate sessions, tied to the
 * current thread of execution.  Follows the Thread Local Session
 * pattern, see {@link http://hibernate.org/42.html }.
 */
public class HibernateSessionFactory ...{

    /** *//** 
     * Location of hibernate.cfg.xml file.
     * Location should be on the classpath as Hibernate uses  
     * #resourceAsStream style lookup for its configuration file. 
     * The default classpath location of the hibernate config file is 
     * in the default package. Use #setConfigFile() to update 
     * the location of the configuration file for the current session.   
     */
    private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
    private static final ThreadLocal threadLocal = new ThreadLocal();
    private  static Configuration configuration = new Configuration();
    private static org.hibernate.SessionFactory sessionFactory;
    private static String configFile = CONFIG_FILE_LOCATION;

    static ...{
        try ...{
            configuration.configure(configFile);
            sessionFactory = configuration.buildSessionFactory();
        } catch (Exception e) ...{
            System.err
                    .println("%%%% Error Creating SessionFactory %%%%");
            e.printStackTrace();
        }
    }
    private HibernateSessionFactory() ...{
    }
    
    /** *//**
     * Returns the ThreadLocal Session instance.  Lazy initialize
     * the <code>SessionFactory</code> if needed.
     *
     *  @return Session
     *  @throws HibernateException
     */
    public static Session getSession() throws HibernateException ...{
        Session session = (Session) threadLocal.get();

        if (session == null || !session.isOpen()) ...{
            if (sessionFactory == null) ...{
                rebuildSessionFactory();
            }
            session = (sessionFactory != null) ? sessionFactory.openSession()
                    : null;
            threadLocal.set(session);
        }

        return session;
    }

    /** *//**
     *  Rebuild hibernate session factory
     *
     */
    public static void rebuildSessionFactory() ...{
        try ...{
            configuration.configure(configFile);
            sessionFactory = configuration.buildSessionFactory();
        } catch (Exception e) ...{
            System.err
                    .println("%%%% Error Creating SessionFactory %%%%");
            e.printStackTrace();
        }
    }

    /** *//**
     *  Close the single hibernate session instance.
     *
     *  @throws HibernateException
     */
    public static void closeSession() throws HibernateException ...{
        Session session = (Session) threadLocal.get();
        threadLocal.set(null);

        if (session != null) ...{
            session.close();
        }
    }

    /** *//**
     *  return session factory
     *
     */
    public static org.hibernate.SessionFactory getSessionFactory() ...{
        return sessionFactory;
    }

    /** *//**
     *  return session factory
     *
     *    session factory will be rebuilded in the next call
     */
    public static void setConfigFile(String configFile) ...{
        HibernateSessionFactory.configFile = configFile;
        sessionFactory = null;
    }

    /** *//**
     *  return hibernate configuration
     *
     */
    public static Configuration getConfiguration() ...{
        return configuration;
    }

}

 

 

 

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration>

<session-factory>
    <property name="connection.username">root</property>
    <property name="connection.url">
        jdbc:mysql://localhost:3306/test
    </property>
    <property name="dialect">
        org.hibernate.dialect.MySQLDialect
    </property>
    <property name="myeclipse.connection.profile">MySql</property>
    <property name="connection.password">数据库密码</property>
    <property name="connection.driver_class">
        com.mysql.jdbc.Driver
    </property>
    <property name="show_sql">true</property>
    <mapping resource="org/myhibernate/Testblob.hbm.xml" />

</session-factory>

</hibernate-configuration>

 3.生成类与表之间的映射,并生成bean

 

package org.myhibernate;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Blob;
import java.sql.SQLException;
import org.hibernate.Hibernate;
import org.hibernate.Session;
import org.hibernate.Transaction;

public class Test ...{
    public void addImage(Testblob testblob) ...{
        Session session = HibernateSessionFactory.getSession();
        FileInputStream images=null;
        Blob img=null;
        try ...{
            images=new FileInputStream("c:/1.jpg");
        } catch (FileNotFoundException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try ...{
            img=Hibernate.createBlob(images);
        } catch (IOException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        testblob.setImage(img);
        Transaction tx=session.beginTransaction();
        try...{
            session.save(testblob);
        }
        catch(Exception ex)...{
            System.out.println("保存异常出现");
            ex.printStackTrace();
        }
        tx.commit();
        session.close();
    }
    
    public void SeeImage()...{
        Session session = HibernateSessionFactory.getSession();
        Testblob testblob=(Testblob)session.load(Testblob.class, new Integer(1));
        Blob img=testblob.getImage();
        FileOutputStream output=null;
        InputStream is=null;
        try ...{
            is=img.getBinaryStream();
        } catch (SQLException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try ...{
            output=new FileOutputStream("c:/2.jpg");
        } catch (FileNotFoundException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        byte[] byt=new byte[102400];
        int len;
        try ...{
            while((len=is.read(byt))!=-1)...{
                output.write(byt,0,len);
            }
        } catch (IOException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try...{
            output.close();
            is.close();
        }catch(Exception ex)...{
            ex.printStackTrace();
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="org.myhibernate.Testblob" table="testblob">
        <id name="id" type="java.lang.Integer">
            <column name="id" />
            <generator class="native" />
        </id>
        <property name="image" type="java.sql.Blob">
            <column name="image" />
        </property>
    </class>
</hibernate-mapping>

4.写个servlet

 

package org.myhibernate;

import java.io.IOException;
import java.io.OutputStream;
import java.sql.Blob;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.hibernate.Session;

public class TestServlet extends HttpServlet ...{
    public TestServlet() ...{
        super();
    }
    public void destroy() ...{
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

        public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException ...{
        doPost(request, response);
    }

        public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException ...{
                Session session = HibernateSessionFactory.getSession();
        Testblob testblob = (Testblob) session.load(Testblob.class,
                new Integer(1));
        Blob img = testblob.getImage();
        OutputStream output = null;
        try ...{
            output = response.getOutputStream();// 得到输出流
        } catch (IOException ex1) ...{
            ex1.printStackTrace(System.out);
        }
        try ...{
            int len=(int)img.length();
            byte[] photo = img.getBytes(1,len);// 从数据库中读出文件
            if (photo != null && photo.length > 0) ...{
                output.write(photo); // 输出到网页上
            }
        } catch (Exception ex) ...{
            ex.printStackTrace(System.out);
        }
    }

        public void init() throws ServletException ...{
        // Put your code here
    }

}

 

5.用一个index.jsp来作为测试的页面

 

<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
  </head>
  
  <body>
    <form action="<%=basePath%>servlet/TestServlet" method="post">
       <input type="submit" value="提交"/>
    </form>
  </body>
</html>