如何使用 jdbc 在 oracle 10g 中插入大 clob 数据（> 4K 个字符）

Question

Could you guys please tell me how to insert clob data using jdbc. Iam using oracle10g database.

I was able to insert clob data having length < 4000 using the below 2 methods

1.

tempClob.length()<4000){
   pstmnt.setClob(colNumber, tempClob );
}

2.

tempClob.length()<4000){
   Reader reader =tempClob.getCharacterStream();
   pstmnt.setClob(colNumber, tempClob );
   pstmnt.setCharacterStream(colNumber, reader, new Long(tempClob.length()).intValue());
}

When the length of the clob data is large for example abt 29k, both these methods fail.

Answer 1

This works on oracle11g jdk5

tempClob.length()<4000){
    byte[] bytes = tempClob.getBytes();
    pstmnt.setCharacterStream(2, new StringReader(new String( bytes  )), bytes.length);
}

Answer 2

If you are using Oracle 11g you will need drivers from here: http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-112010-090769.html

ojdbc5.jar for JDK 1.5 or ojdbc6.jar for JDK 1.6

The jar will need to be included in your classpath.

Amazingly Oracle 11g can store Clobs of 8 to 128 Tera bytes.

Answer 3

Here's som code I found lying around that I think does what you want:

I have a static method like this:

public class DBUtil {
public static CLOB getCLOB(String innStr, Connection conn) throws SQLException, 
                                                   IOException {
  CLOB tempClob = null;
    // If the temporary CLOB has not yet been created, create new
    tempClob = CLOB.createTemporary(conn, true, CLOB.DURATION_SESSION);

    // Open the temporary CLOB in readwrite mode to enable writing
    tempClob.open(CLOB.MODE_READWRITE);
    // Get the output stream to write
    Writer tempClobWriter = tempClob.getCharacterOutputStream();
    // Write the data into the temporary CLOB
    tempClobWriter.write(innStr);

    // Flush and close the stream
    tempClobWriter.flush();
    tempClobWriter.close();

    // Close the temporary CLOB
    tempClob.close();
  return tempClob;
}
}

And then you can use it something like this:

CLOB tempClob = DBUtil.getCLOB(longString, connection);
pstmt.setCLOB(colnumber, tempClob);

This require the entire clob content to be in a string, so it's all loaded into memory, perhaps not suitable for you, but it's been working for my simple needs.

EDIT: I should probably note that I used this code with a plsql procedure call. Haven't tested it directly with sql

Answer 4

have you tried to check the max size of the field... SELECT LENGTH(clobfield) FROM table

see if the field can accomodate the size..