Retrieving BLOB Values with getBinaryStream() Method

JDBC for Oracle - Herong's Tutorial Examples

∟Oracle BLOB (Binary Large Object) - BLOB

∟Retrieving BLOB Values with getBinaryStream() Method

This section describes how to retrieve BLOB values with the ResultSet.getBinaryStream() method.

BLOB values can also be retrieved with the getBinaryStream() method on the ResultSet object, which will return an OutputStream object. Then you can read the BLOB values from the OutputStream object with the read() method. The sample program below shows you how to create OutputStream objects with the getBinaryStream() method. A utility method is included to read all bytes from an OutputStream object and save them in a file.

/* OracleBlobGetBinaryStream.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.io.*;
import java.sql.*;
public class OracleBlobGetBinaryStream {
  public static void main(String [] args) {
    Connection con = null;
    try {
      oracle.jdbc.pool.OracleDataSource ds
        = new oracle.jdbc.pool.OracleDataSource();
      ds.setDriverType("thin");
      ds.setServerName("localhost");
      ds.setPortNumber(1521);
      ds.setDatabaseName("XE");
      ds.setUser("Herong");
      ds.setPassword("TopSecret");
      con = ds.getConnection();

// Retrieving CLOB value with getBinaryStream()
      Statement sta = con.createStatement();
      ResultSet res = sta.executeQuery("SELECT * FROM Image");
      int i = 0;
      while (res.next() && i<3) {
        i++;
        System.out.println("Record ID: "+res.getInt("ID"));
        System.out.println("   Subject = "+res.getString("Subject"));
        InputStream bodyOut = res.getBinaryStream("Body");
        String fileOut = "BlobOut_"+res.getInt("ID")+".bin";
        saveOutputStream(fileOut,bodyOut);
        bodyOut.close();
        System.out.println("   Body = (Saved in "+fileOut+")");
      }
      res.close();

      sta.close();
      con.close();
    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());
      e.printStackTrace();
    }
  }
  public static void saveOutputStream(String name, InputStream body) {
    int c;
    try {
      OutputStream f = new FileOutputStream(name);
      while ((c=body.read())>-1) {
        f.write(c);
      }
      f.close();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

The output looked correct:

herong> java -cp .;ojdbc11.jar OracleBlobGetBinaryStream

Record ID: 2
   Subject = Test of the setBytes() method
   Body = (Saved in BlobOut_2.bin)
Record ID: 3
   Subject = Test of setBinaryStream() methods
   Body = (Saved in BlobOut_3.bin)
Record ID: 4
   Subject = Error test of setBinaryStream() method
   Body = (Saved in BlobOut_4.bin)

I also tested BlobOut_3.bin file to make sure that I am getting my OracleBlobSetBinaryStream.class file back correctly:

herong> del OracleBlobSetBinaryStream.class

herong> copy BlobOut_3.bin OracleBlobSetBinaryStream.class
        1 file(s) copied.

herong> java -cp .;ojdbc11.jar OracleBlobSetBinaryStream

The inserted record:
   Subject = Test of setBinaryStream() methods
   Body = -||+   2 |
...