Java JDBC about Blob and Clob, need to upload a doc file to a MySQL Database

Question

I am currently experimenting on my own, learning some JDBC and how to persist objects to a database. Right now I am trying to upload a Document to the database. I am getting the following error:

Exception in thread "main" java.lang.AbstractMethodError: Method com/mysql/jdbc/PreparedStatement.setClob(ILjava/io/Reader;)V is abstract
    at com.mysql.jdbc.PreparedStatement.setClob(PreparedStatement.java)
    at dao.StudentDAO.uploadResume(StudentDAO.java:156)
    at controller.Test.main(Test.java:30)

Have no clue why this is happening, can someone help me see the error? Here is some of my code:

// this is in my studentDAO class:

private static final String SQL_UPDATE_RESUME = 
        "UPDATE students
        SET resume = ? 
        WHERE socialSecNumber = ?";

public boolean uploadResume(Reader r) {
        PreparedStatement pst;
        //Reader file;

        try{
            pst = con.getConnection().prepareStatement(SQL_UPDATE_RESUME);
            //file = r;
            pst.setClob(1, r);
        }
        catch(SQLException e){
            System.out.println("Error when uploading the resume: " + e);
        }
        finally{
            con.closeConnection();
        }
        return true;
    }

public class Test {
public static void main(String[] args) {


    File file = new File("C:/Users/Carlos L/Desktop/Resume.docx");
    Reader r = null;
    try {
        r = new FileReader(file);
    } catch (FileNotFoundException e) {
        System.out.println("Error when locating the file: "+ e);
    }
    sdao.uploadResume(r);
}

}

It's likely that you JDBC driver does not support CLOB. Have look at Adding Large Object Type Object to Database, which creates a Clob object instead of a Reader — MadProgrammer
– MadProgrammer, Commented Oct 4, 2015 at 22:57
Yeah i substituted the driver, and it worked. The file is now uploaded to the DB now, however it is not legible, i am looking at it through php my admin, I am using XAMPP. — Carlos Luis
– Carlos Luis, Commented Oct 4, 2015 at 23:11

Andreas · Accepted Answer · 2015-10-04 22:48:33Z

2

PreparedStatement.setClob(int parameterIndex, Reader reader) was adding in Java 6, and you're using the JDBC driver from before that.

Upgrade to a Java 6 compatible driver, and your code will work.

answered Oct 4, 2015 at 22:48

Andreas

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3 Comments

Carlos Luis Over a year ago

Yeah youre right, i downloaded the latest driver and it worked. Now when i upload this to the database(I am using XAMPP with php my admin) the contents of the column where I uploaded the document is unreadable, it is all full of nonsensical data.

Andreas Over a year ago

That sounds like a different question. ;-)

Carlos Luis Over a year ago

Lol I dont think i can ask more questions today.

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