Blob: JDBC deals with Binary Data : Blob Binary Data JDBC « Database SQL JDBC « Java






Blob: JDBC deals with Binary Data

 
/*

Database Programming with JDBC and Java, Second Edition
By George Reese
ISBN: 1-56592-616-1

Publisher: O'Reilly

*/


import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

/**
 * Example 4.2.
 */
public class Blobs {
  public static void main(String args[]) {
    if (args.length != 1) {
      System.err.println("Syntax: <java Blobs [driver] [url] "
          + "[uid] [pass] [file]");
      return;
    }
    try {
      Class.forName(args[0]).newInstance();
      Connection con = DriverManager.getConnection(args[1], args[2],
          args[3]);
      File f = new File(args[4]);
      PreparedStatement stmt;

      if (!f.exists()) {
        // if the file does not exist
        // retrieve it from the database and write it to the named file
        ResultSet rs;

        stmt = con.prepareStatement("SELECT blobData "
            + "FROM BlobTest " + "WHERE fileName = ?");

        stmt.setString(1, args[0]);
        rs = stmt.executeQuery();
        if (!rs.next()) {
          System.out.println("No such file stored.");
        } else {
          Blob b = rs.getBlob(1);
          BufferedOutputStream os;

          os = new BufferedOutputStream(new FileOutputStream(f));
          os.write(b.getBytes(0, (int) b.length()), 0, (int) b
              .length());
          os.flush();
          os.close();
        }
      } else {
        // otherwise read it and save it to the database
        FileInputStream fis = new FileInputStream(f);
        byte[] tmp = new byte[1024];
        byte[] data = null;
        int sz, len = 0;

        while ((sz = fis.read(tmp)) != -1) {
          if (data == null) {
            len = sz;
            data = tmp;
          } else {
            byte[] narr;
            int nlen;

            nlen = len + sz;
            narr = new byte[nlen];
            System.arraycopy(data, 0, narr, 0, len);
            System.arraycopy(tmp, 0, narr, len, sz);
            data = narr;
            len = nlen;
          }
        }
        if (len != data.length) {
          byte[] narr = new byte[len];

          System.arraycopy(data, 0, narr, 0, len);
          data = narr;
        }
        stmt = con.prepareStatement("INSERT INTO BlobTest(fileName, "
            + "blobData) VALUES(?, ?)");
        stmt.setString(1, args[0]);
        stmt.setObject(2, data);
        stmt.executeUpdate();
        f.delete();
      }
      con.close();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

           
         
  








Related examples in the same category

1.Read BLOBs data from database
2.Store BLOBs data into database
3.Insert picture to MySQL
4.Demo Display Binary Data From Database
5.Materialize binary data onto client
6.Inserting Image in Database Table
7.Blob and JDBC: Image
8.Blob: Image 2
9.Blob: image 3
10.Insert an Image
11.Retrieve an Image
12.Store and retrieve an object from a table
13.Read CLOBs data from database
14.Getting BLOB Data from a Database Table: how to retrieves bytes from a BLOB.
15.Store CLOBs data into database?
16.Getting and Inserting Binary Data into an Database Table