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终于搞定了CLOB字段得存取,代码和大家分享。

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作者 正文
   发表时间:2004-05-10  
采用得是ORACLE9i数据库,Jboss或Weblogic。
JDBC采用ORACLE9i自带的Class12.jar
-------------
数据库结构:
CREATE TABLE SNCPARAMETERS
(
  ID     NUMBER(19);                             NOT NULL,
  SNCID  NUMBER(19);,
  NAME   VARCHAR2(255);,
  VALUE  CLOB
);

--------------
BO采用xdoclet建立的:
public class SNCParameters extends BaseObject
{

    /**
     * Returns the id.
     *
     * @return      long
     * @hibernate.id
     *          column = "id"
     *          type = "long"
     *          generator-class = "native"
     *          unsaved-value = "null"
     */
    public Long getId();
    {
        return id;
    }

    /**
     *    Sets the Id attribute of the SNCParameters object
     *
     * @param    id  The new Id value
     */
    public void setId(Long id);
    {
        this.id = id;
    }


    /**
     * Returns the name.
     *
     * @return      String
     *
     * @hibernate.property
     *          column = "name"
     *          type = "string"
     *          not-null = "true"
     *          unique = "false"
     */

    public String getName();
    {
        return name;
    }

    /**
     *    Sets the Name attribute of the SNCParameters object
     *
     * @param    name  The new Name value
     */
    public void setName(String name);
    {
        this.name = name;
    }

    /**
     * Returns the sncId.
     *
     * @return      Long
     *
     * @hibernate.property
     *          column = "sncId"
     *          type = "long"
     *          not-null = "true"
     *          unique = "false"
     */

    public Long getSncId();
    {
        return sncId;
    }

    /**
     *    Sets the SncId attribute of the SNCParameters object
     *
     * @param    sncId  The new SncId value
     */
    public void setSncId(Long sncId);
    {
        this.sncId = sncId;
    }

    /**
     * Returns the values.
     *
     * @return      Clob
     *
     * @hibernate.property
     *          column = "value"
     *          type = "clob"
     *          not-null = "true"
     *          unique = "false"
     */

    public Clob getValue();
    {
        return value;
    }

    /**
     *    Sets the Values attribute of the SNCParameters object
     *
     * @param    values  The new Values value
     */
    public void setValue(Clob value);
    {
        this.value = value;
    }
    private Long id;
    private Long sncId;
    private String name;
    private Clob value;
    private String valueString;
    public String getValueString();
    {
        return valueString;
    }
        public void setValueString(String  valueString);
    {
        this.valueString = valueString;
    }
}


注:valueString并不映射到数据库的CLOB字段,只是方便需要使用这个BO的人用GET、SET 处理这个巨长的CLOB字段
------------
xdocLet生成的XML文件:
<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 2.0//EN" 
    "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
    <class
        name="com.idncn.mc.bo.SNCParameters"
        table="SNCParameters"
        dynamic-update="false"
        dynamic-insert="false"
    >

        <id
            name="id"
            column="id"
            type="long"
            unsaved-value="null"
        >
            <generator class="native">
            </generator>
        </id>

        <property
            name="name"
            type="string"
            update="true"
            insert="true"
            column="name"
            not-null="true"
            unique="false"
        />

        <property
            name="sncId"
            type="long"
            update="true"
            insert="true"
            column="sncId"
            not-null="true"
            unique="false"
        />

        <property
            name="value"
            type="clob"
            update="true"
            insert="true"
            column="value"
            not-null="true"
            unique="false"
        />
    </class>

</hibernate-mapping>

--------------------
insert的代码:
    public List batchAddSncParameters(List sncParametersList, Long sncId); throws DbAccessException
    {
        logger.enterMethod();;
        List ret = new ArrayList();;
        try
        {
            sess = getSession();;
            if (sncParametersList != null && sncParametersList.size(); > 0);
            {
                for (int i = 0; i < sncParametersList.size();; i++);
                {
                    SNCParameters cp = (SNCParameters); sncParametersList.get(i);;
                    long newId = -1;
                    if (cp != null);
                    {
                        SNCParameters cpNew = new SNCParameters();;
                        cpNew.setSncId(sncId);;
                        cpNew.setName(cp.getName(););;
                        cpNew.setValue(Hibernate.createClob(" "););;
                        newId = ((Long); sess.save(cpNew););.longValue();;
                        sess.flush();;

			sess.refresh(cpNew, LockMode.UPGRADE);;
                        String content = cp.getValueString();;

                        String appserver = System.getProperty("appserver", "jboss");;
                        if (!appserver.equalsIgnoreCase("jboss"););
                        {
                            //weblogic
                            OracleThinClob clob = (OracleThinClob); cpNew.getValue();;
                            java.io.Writer pw = clob.getCharacterOutputStream();;
                            pw.write(content);;
                            pw.flush();;
                            pw.close();;
			}
                        else
                        {
                            //jboss
                            oracle.sql.CLOB clob = (oracle.sql.CLOB); cpNew.getValue();;
                            java.io.Writer pw = clob.getCharacterOutputStream();;
                            pw.write(content);;
                            pw.flush();;
                            pw.close();;
                        }
                        ret.add(new Long(newId););;
                    }
                }
            }
        }
        catch (Exception e);
        {
            logger.error(e);;
            ErrorReason errorReason = new ErrorReason(ErrorReason.INSERT_OBJECT_FAILED_REASON);;
            throw new DbAccessException(DbAccessException.DBA_OPERATE_EXCEPTION, errorReason);;
        }
        finally
        {
            closeSession(sess);;
            logger.exitMethod();;
        }
        return ret;
    }

-----------------
注:Weblogic必须使用weblogic.jdbc.vendor.oracle.OracleThinClob
---------------------
读取CLOB字段:
    public List selectSncParametersBySncId(long sncId); throws DbAccessException
    {
        logger.enterMethod();;
        List ret = new ArrayList();;
        try
        {
            sess = getSession();;
            String query = "select cp from cp in class com.idncn.mc.bo.SNCParameters where cp.sncId = ?";
            logger.debug("SQL=" + query);;
            List iter = sess.find(query, new Long(sncId);, Hibernate.LONG);;
            for (int i = 0; i < iter.size();; i++);
            {
                SNCParameters newCp = new SNCParameters();;
                SNCParameters cp = (SNCParameters); (iter.get(i););;
                logger.debug("after fetch:" + cp);;
                newCp.setId(cp.getId(););;
                newCp.setSncId(cp.getSncId(););;
                newCp.setName(cp.getName(););;
                java.sql.Clob clob = cp.getValue();;
                if (clob != null);
                {
                    logger.debug("b===" + clob.length(););;
                    String b = clob.getSubString(1, (int); clob.length(););;
                    //logger.debug("b==="+b);;
                    newCp.setValueString(b);;
                }
                ret.add(newCp);;
            }
        }
        catch (Exception e);
        {
            logger.error(e);;
            ErrorReason errorReason = new ErrorReason(ErrorReason.SELECT_FAILED_REASON);;
            throw new DbAccessException(DbAccessException.DBA_OPERATE_EXCEPTION, errorReason);;
        }
        finally
        {
            closeSession(sess);;
            logger.exitMethod();;
        }
        return ret;
    }

---------------
更新这个字段的代码:
    public void updateSncParameters(SNCParameters newParam); throws DbAccessException
    {
        logger.enterMethod();;
        try
        {
            sess = getSession();;

            Long id = newParam.getId();;
            SNCParameters pp = (SNCParameters); sess.load(SNCParameters.class, id, net.sf.hibernate.LockMode.UPGRADE);;

            pp.setSncId(newParam.getSncId(););;
            pp.setName(newParam.getName(););;
            pp.setId(newParam.getId(););;

            String newValue = newParam.getValueString();;
            logger.debug("Update Length =" + newValue.length(););;

            String appserver = System.getProperty("appserver", "jboss");;
            logger.debug("appserver: " + appserver);;
            if (!appserver.equalsIgnoreCase("jboss"););
            {
                //weblogic
                OracleThinClob clob = (OracleThinClob); pp.getValue();;
                if (pp != null);
                {
                    java.io.Writer pw = clob.getCharacterOutputStream();;
                    pw.write(newValue);;
                    pw.flush();;
                    pw.close();;
                }
            }
            else
            {
                //jboss
                oracle.sql.CLOB clob = (oracle.sql.CLOB); pp.getValue();;
                if (pp != null);
                {
                    java.io.Writer pw = clob.getCharacterOutputStream();;
                    pw.write(newValue);;
                    pw.flush();;
                    pw.close();;
                }
            }
        }
        catch (Exception e);
        {
            logger.error(e);;
            ErrorReason errorReason = new ErrorReason(ErrorReason.UPDATE_OBJECT_FAILED_REASON);;
            throw new DbAccessException(DbAccessException.DBA_OPERATE_EXCEPTION, errorReason);;
        }
        finally
        {
            closeSession(sess);;
            logger.exitMethod();;
        }
    }
   发表时间:2004-06-08  
OracleThinClob clob = (OracleThinClob) pp.getValue();

请问我怎么执行到这一步出现java.lang.ClassCastException
0 请登录后投票
   发表时间:2004-09-28  
请问我用hibernate插入clob的时候出现乱码是怎么回事?
数据库:oracle9i 
appS:  tomcat
0 请登录后投票
   发表时间:2004-10-11  
随便找个编码就成了,

我用java.net.URLEncoder.encode(),编码,取出的时候再解码就行了,
0 请登录后投票
   发表时间:2004-10-16  
DreamOne

换换你的wls的连接池的驱动啊,
0 请登录后投票
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