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1. 必须保证在一个事务内处理：JDBC connection autocommit conn.setAutoCommit(false);
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2. 插入记录用empty_clob()函数带入空CLOB字段：Insert into table with CLOB column as empty_clob();
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3. 用select把空CLOB对象查出，注意必须带for update子句来告知数据库接下来要修改该记录，否则SQL语句会返回错误告诉你没有for update子句：Select clob column with “for update” option like “select clob_field from clob_table where rowid=1 for update”;
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4. 将返回的CLOB字段对象由JDK的Clob转换成Oracle 库的CLOB对象：Turn the return from java.sql.Clob to Oracle.sql.CLOB:
Clob clob = (Clob)rs.getClob("clob_field");
oracle.sql.CLOB tmpclob = (oracle.sql.CLOB)clob;
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5. 用字符串填充该CLOB对象：
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BufferedWriter bw = new BufferedWriter(tmpclob.getCharacterOutputStream());
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bw.write(clobClValueArray.get(i).toString());
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bw.flush();
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6. 用结构化语句对象PreparedStatement实现DML操作:
PreparedStatement pstmt1 = conn.prepareStatement(“update clob_table set clob_field=? Where rowid=1”);
pstmt1.setClob(1, tmpclob);
pstmt1.execute();
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7. 把事务提交实现CLOB字段操作。Commit the update: conn.commit();
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8．读取CLOB内容也很简单：
PreparedStatement pstmt = conn.prepareStatement("select clob_field from clob_table where rowid=1");
ResultSet rs = pstmt.executeQuery();
Clob clob = (Clob)rs.getClob("clob_field");
String str;
str = clob.getSubString((long)1, clob.length());
}
本文转自 dannyy1026 51CTO博客，原文链接:
http://blog.51cto.com/dannyyuan/550861
