import java.io.*;
import java.util.*;
import java.sql.*;
import oracle.jdbc.driver.*;
import oracle.sql.*;

public class Slob {
  
	public Connection getConnectionJDBC(String url, String username, String password) {
        Connection conn = null;

        
        try {
			Class.forName ("oracle.jdbc.driver.OracleDriver");
			conn = DriverManager.getConnection(url,username,password);
		}
        catch (SQLException se) {
            System.out.println("SQL Exception (Slob): " + se);
		}
        catch (Exception e) {
            System.out.println("Exception (Slob): " + e);
		}
        return conn;
    }

    //This procedure will read a bolb attribute and put its content into a file.
	public boolean read (String outputPath,                     //path where the new file will be stored
                         String outputFileName,                 //name of the new file that stores the blob
        		         String column,                         //the blob column
                         String table,                          //table being searched
	                     long id,                               //for identification purpose
                         String id_column) {                    //column used in identification of the record

        // Declare local variables
   		Connection conn = null;
		PreparedStatement stmt = null;
    	ResultSet rs = null;
		Blob blob = null;
		FileOutputStream out = null;
		InputStream in = null;
       	int length = 0;
       	boolean readStatus = true;
       	String absolutePath = null;
       	String readStr = "select " + column + " from "  + table +
                         " where "   + id_column + " = ?";

		try {
            String url = "jdbc:oracle:thin:@D5T6B40B:1521:second";
            String username = "scott";
            String password = "tiger";
            conn = getConnectionJDBC(url, username, password);
            conn.setAutoCommit(false);

       		stmt = conn.prepareStatement(readStr);
			stmt.setLong(1, id);

            rs = stmt.executeQuery();

			if (rs.next()) {

				blob = rs.getBlob(column);
	        	length = (int) blob.length();
	        	byte [] buffer = new byte [1000];
				absolutePath = outputPath + outputFileName;
		    	out = new FileOutputStream(new File(absolutePath).getCanonicalPath());
		    	in = blob.getBinaryStream();

	        	while ((length = in.read(buffer)) != -1) {
		       		out.write(buffer, 0, length);
				}

				conn.commit();
	        }
            else {
				readStatus = false;
			}
	    }
        catch (SQLException se) {
        	System.out.println("SQL Error on blob read (Slob): " + se);
			readStatus = false;
		}
	    catch ( Exception e ) {
        	System.out.println("Other Error on blob read (Slob): " + e);
	        readStatus = false;
	    }
        finally {
            try {
                if (out != null)
	        		out.close ( );
                if (in != null)
	        		in.close ( );
                if (rs != null)
	       			rs.close ( );
                if (stmt != null)
	        		stmt.close ( );
                if (conn != null)
	        		conn.close ( );
			}
            catch (SQLException se2) {
        		System.out.println("SQL Error releasing resources (Slob read) : " + se2);
                readStatus = false;
			}
            catch (Exception e2) {
        		System.out.println("Other error releasing resources (Slob read) : " + e2);
                readStatus = false;
			}
		}
		return readStatus;
	}   //end of read

    //This procedure will write the content of a file into a blob field
	public boolean write (String inputPath,              //path where the file will be used
                         String inputFileName,           //name of the file that will be used to write to a blob attribute
        		         String column,                  //the blob column
                         String table,                   //table being searched
	                     long id,                        //for identification purpose
                         String id_column) {             //column used in identification of the record

        // Declare local variables
   		Connection conn = null;
		PreparedStatement stmt = null;
    	ResultSet rs = null;
		BLOB blob = null;
       	int length = 0;
       	boolean readStatus = true;
      	String semiAbsolutePath = null;
		File binaryFile = null;
		FileInputStream in = null;
		OutputStream out = null;
        String queryStr  = "select * from " + table + " where " +
                            id_column + " = ? for update";

		try {
            String url = "jdbc:oracle:thin:@D5T6B40B:1521:second";
            String username = "scott";
            String password = "tiger";
	   		conn = getConnectionJDBC(url, username, password);
            conn.setAutoCommit(false);

        	stmt = conn.prepareStatement(queryStr);
        	stmt.setLong(1, id);

			rs = stmt.executeQuery();
            rs.next();

            blob = ((OracleResultSet) rs).getBLOB(column);
        	binaryFile = new File(inputPath + inputFileName);
			in = new FileInputStream(binaryFile);
			out = blob.getBinaryOutputStream();
			int chunk = blob.getChunkSize();
        	byte[] buffer = new byte[chunk];
			length = -1;

			while ((length = in.read(buffer)) != -1) {
				out.write ( buffer, 0, length );
			}

        	if (blob.length() != binaryFile.length())
				out.flush();

		}
        catch (SQLException se) {
        	System.out.println("SQL Error on blob write (Slob): " + se);
			readStatus = false;
		}
	    catch ( Exception e ) {
        	System.out.println("Other Error on blob write (Slob): " + e);
	        readStatus = false;
	    }
        finally {
            try {
                if (out != null)
	        		out.close ( );
                if (in != null)
	        		in.close ( );
                if (rs != null)
	       			rs.close ( );
                if (stmt != null)
	        		stmt.close ( );
                if (conn != null)
	        		conn.close ( );
			}
            catch (SQLException se2) {
        		System.out.println("SQL Error releasing resources (Slob read) : " + se2);
                readStatus = false;
			}
            catch (Exception e2) {
        		System.out.println("Other error releasing resources (Slob read) : " + e2);
                readStatus = false;
			}
		}
		return readStatus;
    }   //end of write

    public static void main(String[] argv) {
        Slob s = new Slob();
        for (int i = 0; i < argv.length; i++)
        {
            System.out.println(argv[i]);
        } //end of listing arguments
        
        if (argv[0].equals("Read"))
            s.read("C:/Classes/", argv[1], "Picture", "Emp", 7788, "empno");
        else
            s.write("C:/Classes/", argv[1], "Picture", "Emp", 7788, "empno");
    }   //end of main
}

/*
The following lines show the compilation and testing of the class:
C:\Tomcat321\CS643>javac Slob.java

C:\Tomcat321\CS643>java Slob "write" "BryanTBall.jpg"
write
BryanTBall.jpg

C:\Tomcat321\CS643>java Slob "Read" "testread.jpg"
Read
testread.jpg

C:\Tomcat321\CS643>java Slob "write" "new_logo.doc"
write
new_logo.doc

C:\Tomcat321\CS643>java Slob "Read" "test_logo.doc"
Read
test_logo.doc

C:\Tomcat321\CS643>
*/