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第一时间想到spring,因为spring对orm工具有封装, 像ibatis,hibernate等,在spring.jar中大概翻了一下包,根据包名和类名发现如下可疑类org.springframework.orm.ibatis.support.ClobStringTypeHandler 根据源码跟踪到了 org.springframework.jdbc.support.lob.OracleLobHandler 这个类才是内有乾坤,有我想要的一切东西,嘿嘿,不好意思了,统统抄来.
在spring包中有个org.springframework.jdbc.support.lob.AbstractLobHandler这里面定义了基本的Clob和Blog处理方法
org.springframework.jdbc.support.lob.DefaultLobHandler是默认的实现,除了Oracle其他数据库使用此实现
org.springframework.jdbc.support.lob.OracleLobHandler是专门用于Oracle的实现,可见Oracle的BT,为了不造成直接包依赖,相关的调用都是利用反射完成的.有兴趣的朋友可以去阅读下这两个类,以便了解Oracle的特殊性.
经过分析,将Clob的创建,以及与String的互转代码放出来供大家使用.当然不可能完全copy了,我做了些简化处理,不过已经测试了,没用问题.更多细节请查阅spring的org.springframework.jdbc.support.lob包源码.
SqlUtil类是我为了方便测试写的,大家靠代码就能够猜出来其内容了,所以就不全贴了,只贴本文的主题部分.
/**
*
* Description:创建Clob或者Blob
*
* @param conn数据库连接对象
* @param lobClassName
* oracle.sql.CLOB或者oracle.sql.BLOB
* @return oracle.sql.CLOB或者oracle.sql.BLOB对象
* @throws Exception
* @blog blog.csdn.ne t/sunyujia/
* @mail
[email protected]
* @since：Oct 1, 2008 6:42:08 PM
*/
public static Object createOracleLob(Connection conn, String lobClassName)
throws Exception {
Class lobClass = conn.getClass().getClassLoader().loadClass(
lobClassName);
final Integer DURATION_SESSION = new Integer(lobClass.getField(
"DURATION_SESSION").getInt(null));
final Integer MODE_READWRITE = new Integer(lobClass.getField(
"MODE_READWRITE").getInt(null));
Method createTemporary = lobClass.getMethod("createTemporary",
new Class[] { Connection.class, boolean.class, int.class });
Object lob = createTemporary.invoke(null, new Object[] { conn, false,
DURATION_SESSION });
Method open = lobClass.getMethod("open", new Class[] { int.class });
open.invoke(lob, new Object[] { MODE_READWRITE });
return lob;
}
/**
*
* Description:将Clob对象转换为String对象,Blob处理方式与此相同
*
* @param clob
* @return
* @throws Exception
* @mail
[email protected]
* @blog blog.csdn.ne t/sunyujia/
* @since：Oct 1, 2008 7:19:57 PM
*/
public static String oracleClob2Str(Clob clob) throws Exception {
return (clob != null ? clob.getSubString(1, (int) clob.length()) : null);
}
/**
*
* Description:将string对象转换为Clob对象,Blob处理方式与此相同
*
* @param str
* @param lob
* @return
* @throws Exception
* @mail
[email protected]
* @blog blog.csdn.ne t/sunyujia/
* @since：Oct 1, 2008 7:20:31 PM
*/
public static Clob oracleStr2Clob(String str, Clob lob) throws Exception {
Method methodToInvoke = lob.getClass().getMethod(
"getCharacterOutputStream", (Class[]) null);
Writer writer = (Writer) methodToInvoke.invoke(lob, (Object[]) null);
writer.write(str);
writer.close();
&n-
bsp;return lob;
}
/**
*
* Description: 全部源码查考自
* org.springframework.jdbc.support.lob.OracleLobHandler
*
* @param args
* @throws Exception
* @mail
[email protected]
* @blog blog.csdn.ne t/sunyujia/
* @since：Oct 1, 2008 7:26:16 PM
*/
public static void main(String[] args) throws Exception {
//创建数据源略
Connection conn = SqlUtil.getConnection();
Clob clob = (Clob) createOracleLob(conn, "oracle.sql.CLOB");// BLOB的话传oracle.sql.BLOB
// create table testTb (TheClob Clob);
PreparedStatement pstmt = conn
.prepareStatement("insert into testTb (TheClob) values (?)");
pstmt.setClob(1, oracleStr2Clob("test", clob));
pstmt.execute();
SqlUtil.closeStmt(pstmt);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from testTb");
while (rs.next()) {
String str = oracleClob2Str(rs.getClob(1));
System.out.println(str);
}
SqlUtil.closeRs(rs);
SqlUtil.closeStmt(stmt);
SqlUtil.closeConn(conn);
}
