Working with LOBs

This section has these subsections:

• Getting BLOB and CLOB Locators

• Passing BLOB and CLOB Locators

• Reading and Writing BLOB and CLOB Data

• Creating and Populating a BLOB or CLOB Column

• Accessing and Manipulating BLOB and CLOB Data

• Getting BFILE Locators

• Passing BFILE Locators

• Reading BFILE Data

• Creating and Populating a BFILE Column

• Accessing and Manipulating BFILE Data

LOBs can be either internal or external. Internal LOBs, as their name suggests, are stored inside database tablespaces in a way that optimizes space and provides efficient access. The JDBC drivers provide support for two types of internal LOBs: BLOBs (unstructured binary data) and CLOBs (single-byte character data). BLOB and CLOB data is accessed and referenced by using a locator which is stored in the database table and points to the BLOB or CLOB data.

External LOBs (BFILES) are large binary data objects stored in operating system files outside of database tablespaces. These files use reference semantics. They may also be located on tertiary storage devices such as hard disks, CD-ROMs, PhotoCDs and DVDs. Like BLOBs and CLOBs, a BFILE is accessed and referenced by a locator which is stored in the database table and points to the BFILE data.

This section describes how you use JDBC and the oracle.sql.* classes to work with LOBs. To work with LOB data, you must first obtain its locator from the table. Then, you can read data from or write data to the LOB and perform various types of data manipulation. This section also describes how to create and populate a LOB column in a table.

The JDBC drivers support these oracle.sql.* classes for BLOBs, CLOBs, and BFILEs:

• oracle.sql.BLOB

• oracle.sql.CLOB

• oracle.sql.BFILE

The oracle.sql.BLOB and CLOB classes implement the oracle.jdbc2.Blob and Clob interfaces, respectively. In contrast, BFILEs have no oracle.jdbc2 interface.

Instances of these classes contain only the locators for these datatypes, not the data. After accessing the locators, you must perform some additional steps to access the data. These steps are described in "Reading and Writing BLOB and CLOB Data" and "Reading BFILE Data".

Getting BLOB and CLOB Locators

Given a standard JDBC result set or callable statement object that includes BLOB or CLOB locators, you can access the locators by using the standard ResultSet.getObject() method. This method returns an oracle.sql.BLOB object or oracle.sql.CLOB object, as applicable (but note that it returns the BLOB or CLOB into a variable of type oracle.jdbc2.Blob or oracle.jdbc2.Clob).

You can also access the locators by casting your result set to OracleResultSet or your callable statement to OracleCallableStatement and using the getOracleObject(), getBLOB(), or getCLOB() method, as appropriate.

In the OracleResultSet and OracleCallableStatement classes, getBlob() returns oracle.jdbc2.Blob, and getBLOB() returns oracle.sql.BLOB. Similarly, getCLOB() returns oracle.jdbc2.CLOB and getClob() returns oracle.sql.Clob.

Notes: If using getObject() or getOracleObject(), then remember to cast the output as necessary. For more information, see "Casting Your get Method Return Values". Refer the Javadoc for more information about specific features of the oracle.sql.BLOB and oracle.sql.CLOB classes.

Example: Getting BLOB and CLOB Locators from a Result Set

Assume the database has a table called lob_table with a column for a BLOB locator, blob_col, and a column for a CLOB locator, clob_col. This example assumes that you have already created the Statement object, stmt.

First, select the LOB locators into a standard result set, then get the LOB data into appropriate Java classes:

// Select LOB locator into standard result set.
ResultSet rs =
   stmt.executeQuery ("SELECT blob_col, clob_col FROM lob_table");
while (rs.next())
{
   // Get LOB locators into Java wrapper classes.
   oracle.jdbc2.Blob blob = (oracle.jdbc2.Blob)rs.getObject(1);
   oracle.jdbc2.Clob clob = (oracle.jdbc2.Clob)rs.getObject(2);
   [...process...]
}

The output is cast to oracle.jdbc2.Blob and Clob. As an alternative, you can cast the output to oracle.sql.BLOB and CLOB to take advantage of extended functionality offered by the oracle.sql.* classes. For example, you can rewrite the above code to get the LOB locators as:

   // Get LOB locators into Java wrapper classes.
   oracle.sql.BLOB blob = (BLOB)rs.getObject(1);
   oracle.sql.CLOB clob = (CLOB)rs.getObject(2);
   [...process...]

Example: Getting a CLOB Locator from a Callable Statement

The callable statement methods for retrieving LOBs are identical to the result set methods. In the case of a callable statement, register the output parameter as OracleTypes.BLOB or OracleTypes.CLOB.

For example, if you have an OracleCallableStatement ocs that calls a function func that has a CLOB output parameter, then set up the callable statement as follows:

OracleCallableStatement ocs = 
   (OracleCallableStatement)conn.prepareCall("{? = call func()}")
ocs.registerOutParameter(1, OracleTypes.CLOB);
ocs.executeQuery()
oracle.sql.CLOB clob = ocs.getCLOB(1);

Passing BLOB and CLOB Locators

To pass a LOB locator to a prepared statement or callable statement (to update a LOB locator in the database, for example), you can use the generic setObject() method, or you can cast the statement to OraclePreparedStatement or OracleCallableStatement and use the setOracleObject(), setBLOB(), or setCLOB() method, as appropriate. These methods take the parameter index and a BLOB object or CLOB object as input.

Example: Passing a BLOB Locator to a Prepared Statement

If you have an OraclePreparedStatement ops where its first parameter is a BLOB named my_blob, then input the BLOB to the prepared statement as follows:

OraclePreparedStatement ops = (OraclePreparedStatement)conn.prepareStatement
     
("INSERT INTO blob_table VALUES(?)"); 

     ops.setBLOB(1, my_blob);
ops.execute();
    

Example: Passing a CLOB Locator to a Callable Statement

If you have an OracleCallableStatement ocs where its first parameter is a CLOB, then input the CLOB to the callable statement as follows:

OracleCallableStatement ocs = 
   (OracleCallableStatement)conn.prepareCall("{? := call func()}")
ocs.setClob(1, my_clob)
ocs.execute();

Reading and Writing BLOB and CLOB Data

The SQL SELECT statement queries for LOB locators. Once you have the locator, you can read and write the LOB data from JDBC. LOB data is materialized as a Java stream. However, unlike most Java streams, a locator representing the LOB data is stored in the table. Thus, you can access the LOB data at any time during the life of the connection.

To read and write the LOB data, use the methods in the oracle.sql.BLOB or oracle.sql.CLOB class, as appropriate. These classes provide functionality such as reading from the LOB into an input stream, writing from an output stream into a LOB, determining the length of a LOB, and closing a LOB.

Notes: The implementation of the data access API uses direct native calls in the JDBC OCI and Server drivers, thereby providing better performance. You can use the same API on the LOB classes in all Oracle 8.1.5 JDBC drivers. In the case of the JDBC Thin driver only, the implementation of the data access API uses the DBMS_LOB package internally. You never have to use DBMS_LOB directly. This is in contrast to the 8.0.x drivers. For more information on the DBMS_LOB package, see the Oracle8i Application Developer's Guide - Large Objects (LOBs) and the Oracle8i Application Developer's Reference - Packages.

To read and write LOB data, you can use these methods:

• To read from a BLOB, use the getBinaryStream() method of an oracle.sql.BLOB object to retrieve the entire BLOB as an input stream. This returns a java.io.InputStream object.

  As with any InputStream object, use one of the overloaded read() methods to read the LOB data and use the close() method when you finish.

• To write to a BLOB, use the getBinaryOutputStream() method of an oracle.sql.BLOB object to retrieve the BLOB as an output stream. This returns a java.io.OutputStream object to be written back to the BLOB.

  As with any OutputStream object, use one of the overloaded write() methods to update the LOB data and use the close() method when you finish.

• To read from a CLOB, use the getAsciiStream() or getCharacterStream() method of an oracle.sql.CLOB object to retrieve the entire CLOB as an input stream. The getAsciiStream() method returns an ASCII input stream in a java.io.InputStream object; the getCharacterStream() method returns a Unicode input stream in a java.io.Reader object.

  As with any InputStream or Reader object, use one of the overloaded read() methods to read the LOB data and use the close() method when you finish.

  You can also use the getSubString() method of oracle.sql.CLOB object to retrieve a subset of the CLOB as a character string of type java.lang.String.

• To write to a CLOB, use the getAsciiOutputStream() or getCharacterOutputStream() method of an oracle.sql.CLOB object to retrieve the CLOB as an output stream to be written back to the CLOB. The getAsciiOutputStream() method returns an ASCII output stream in a java.io.OutputStream object; the getCharacterOutputStream() method returns a Unicode output stream in a java.io.Writer object.

  As with any OutputStream or Writer object, use one of the overloaded write() methods to update the LOB data and use the close() method when you finish.

  Notes: The stream "write" methods described in this section write directly to the database when you write to the output stream. You do not need to execute an UPDATE/COMMIT to write the data. When writing to or reading from a CLOB, the JDBC drivers handle all character set conversions for you.

Example: Reading BLOB Data

Use the getBinaryStream() method of the oracle.sql.BLOB class to read BLOB data. The getBinaryStream() method reads the BLOB data into a binary stream.

The following example uses the getBinaryStream() method to read BLOB data into a byte stream and then reads the byte stream into a byte array (returning the number of bytes read as well).

// Read BLOB data from BLOB locator.
InputStream byte_stream = my_blob.getBinaryStream();
byte [] byte_array = new byte [10];
int bytes_read = byte_stream.read(byte_array);
...

Example: Reading CLOB Data

The following example uses the getCharacterStream() method to read CLOB data into a Unicode character stream. It then reads the character stream into a character array (returning the number of characters read as well).

// Read CLOB data from CLOB locator into Reader char stream.
Reader char_stream = my_clob.getCharacterStream();
char [] char_array = new char [10];
int chars_read = char_stream.read (char_array, 0, 10);
...

The next example uses the getAsciiStream() method of the oracle.sql.CLOB class to read CLOB data into an ASCII character stream. It then reads the ASCII stream into a byte array (returning the number of bytes read as well).

// Read CLOB data from CLOB locator into Input ASCII character stream
Inputstream asciiChar_stream = my_clob.getAsciiStream(); 
   byte[] asciiChar_array = new byte[10]; 
   int asciiChar_read = asciiChar_stream.read(asciiChar_array,0,10);

Example: Writing BLOB Data

Use the getBinaryOutputStream() method of an oracle.sql.BLOB object to write BLOB data.

The following example reads a vector of data into a byte array, then uses the getBinaryOutputStream() method to write an array of character data to a BLOB.

java.io.OutputStream outstream;

// read data into a byte array 
byte[] data = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};

// write the array of binary data to a BLOB
outstream = ((BLOB)my_blob).getBinaryOutputStream();
outstream.write(data);
...

Example: Writing CLOB Data

Use the getCharacterOutputStream() method or the getAsciiOutputStream() method to write data to a CLOB. The getCharacterOutputStream() method returns a Unicode output stream; the getAsciiOutputStream() method returns an ASCII output stream.

The following example reads a vector of data into a character array, then uses the getCharacterOutputStream() method to write the array of character data to a CLOB. The getCharacterOutputStream() method returns a java.io.Writer object in an oracle.sql.CLOB, not an oracle.jdbc2.Clob.

java.io.Writer writer

// read data into a character array
char[] data = {'0','1','2','3','4','5','6','7','8','9'};

// write the array of character data to a CLOB 
writer = ((CLOB)my_clob).getCharacterOutputStream();
writer.write(data);
writer.flush();
writer.close();
...

The next example reads a vector of data into a byte array, then uses the getAsciiOutputStream() method to write the array of ASCII data to a CLOB. Because getAsciiOutputStream() returns an ASCII output stream, you must cast the output to a oracle.sql.CLOB datatype.

java.io.OutputStream out

// read data into a byte array
byte[] data = {'0','1','2','3','4','5','6','7','8','9'};

// write the array of ascii data to a CLOB 
out = ((CLOB)clob).getAsciiOutputStream();
out.write(data);
out.flush();
out.close();

Creating and Populating a BLOB or CLOB Column

You create and populate a BLOB or CLOB column in a table by using SQL statements.

Note: To create a BLOB or CLOB column in a table, you must use SQL statements. Using the Java new, such as "new BLOB" or "new CLOB" will not work.

You create a BLOB or CLOB column in a table with the SQL CREATE TABLE statement. Then, you populate the LOB. This includes creating the LOB entry in the table, obtaining the LOB locator, creating a file handler for the data (if you are reading the data from a file), and then copying the data into the LOB.

Creating a BLOB or CLOB Column in a New Table

To create a BLOB or CLOB column in a new table, execute the SQL CREATE TABLE statement. The following example code creates a BLOB column in a new table. This example assumes that you have already created your Connection object conn and Statement object stmt:

String cmd = "CREATE TABLE my_blob_table (x varchar2 (30), c blob)";
     
stmt.execute (cmd);


         

In this example, the VARCHAR2 column designates a row number, such as one or two, and the blob column stores the locator of the BLOB data.

Populating a BLOB or CLOB Column in a New Table

This example demonstrates how to populate a BLOB or CLOB column by reading data from a stream. These steps assume that you have already created your Connection object conn and Statement object stmt. The table my_blob_table is the table that was created in the previous section.

The following example writes the GIF file john.gif to a BLOB.

1. Begin by using SQL statements to create the BLOB entry in the table. Use the empty_blob syntax to create the BLOB locator.

   stmt.execute ("insert into my_blob_table values ('row1', empty_blob()");
   
   

2. Get the BLOB locator from the table.

   BLOB blob;
   cmd = "SELECT * FROM my_blob_table WHERE X='row1'";
   ResultSet rest = stmt.executeQuery(cmd);
   BLOB blob = ((OracleResultSet)rset).getBLOB(2);
   
   

3. Declare a file handler for the john.gif file, then print the length of the file. This value will be used later to ensure that the entire file is read into the BLOB. Next, create a FileInputStream object to read the contents of the GIF file, and an OutputStream object to retrieve the BLOB as a stream.

   File binaryFile = new File("john.gif");
   System.out.println("john.gif length = " + binaryFile.length());
       FileInputStream instream = new FileInputStream(binaryFile);
       OutputStream outstream = blob.getBinaryOutputStream();
   
   

4. Call getChunkSize() to determine the ideal chunk size to write to the BLOB, then create the buffer byte array.

       int chunk = blob.getChunkSize();
       byte[] buffer = new byte[chunk];
      int length = -1;
   
   

5. Use the read() method to read the GIF file to the byte array buffer, then use the write() method to write it to the BLOB. When you finish, close the input and output streams.

      while ((length = instream.read(buffer)) != -1)
        outstream.write(buffer, 0, length);
     instream.close();
     outstream.close();
   
   

Once your data is in the BLOB or CLOB, you can manipulate the data. This is described in the following section, "Accessing and Manipulating BLOB and CLOB Data".

Accessing and Manipulating BLOB and CLOB Data

Once you have your BLOB or CLOB locator in a table, you can access and manipulate the data to which it points. To access and manipulate the data, you first must select their locators from a result set or from a callable statement. "Getting BLOB and CLOB Locators" describes these techniques in detail.

After you select the locators, you can get the BLOB or CLOB data. You will usually want to cast the result set to the OracleResultSet datatype so that you can retrieve the data in oracle.sql.* format. After getting the BLOB or CLOB data, you can manipulate it however you want.

This example is a continuation of the example in the previous section. It uses the SQL SELECT statement to select the BLOB locator from the table my_blob_table into a result set. The result of the data manipulation is to print the length of the BLOB in bytes.

// Select the blob - what we are really doing here
// is getting the blob locator into a result set 
BLOB blob;
cmd = "SELECT *  FROM my_blob_table";
ResultSet rset = stmt.executeQuery (cmd)

// Get the blob data - cast to OracleResult set to 
// retrieve the data in oracle.sql format 
String index = ((OracleResultSet)rset).getString(1);
blob = ((OracleResultSet)rset).getBLOB(2);

// get the length of the blob
int length = blob.getlength();

// print the length of the blob
System.out.println("blob length" + length);

// read the blob into a byte array 
// then print the blob from the array
byte bytes[] = blob.getBytes(0, length);
printBytes(bytes, length);

Getting BFILE Locators

Given a standard JDBC result set or callable statement object that includes BFILE locators, you can access the locators by using the standard ResultSet.getObject() method. This method returns an oracle.sql.BFILE object.

You can also access the locators by casting your result set to OracleResultSet or your callable statement to OracleCallableStatement and using the getOracleObject() or getBFILE() method.

Notes: In the OracleResultSet and OracleCallableStatement classes, getBFILE() and getBfile() both return oracle.sql.BFILE. There is no oracle.jdbc2 class for BFILE. If using getObject() or getOracleObject(), remember to cast the output, as necessary. For more information, see "Casting Your get Method Return Values".

Example: Getting a BFILE locator from a Result Set

Assume that the database has a table called bfile_table with a single column for the BFILE locator bfile_col. This example assumes that you have already created your Statement object stmt.

Select the BFILE locator into a standard result set. If you cast the result set to an OracleResultSet, you can use getBFILE() to get the BFILE data:

// Select the BFILE locator into a result set
ResultSet rs = stmt.executeQuery("SELECT bfile_col FROM bfile_table"); 
   while (rs.next()) 
   {
       oracle.sql.BFILE my_bfile = ((OracleResultSet)rs).getBFILE(1); 
    }; 
 

Note that as an alternative, you can use getObject() to return the BFILE locator. In this case, since getObject() returns a java.lang.Object, cast the results to BFILE. For example:

       oracle.sql.BFILE my_bfile = (BFILE)rs.getObject(1); 

Example: Getting a BFILE Locator from a Callable Statement

Assume you have an OracleCallableStatement ocs that calls a function func that has a BFILE output parameter. The following code example sets up the callable statement, registers the output parameter as OracleTypes.BFILE, executes the statement, and retrieves the BFILE locator:

OracleCallableStatement ocs = 
   (OracleCallableStatement)conn.prepareCall("{? = call func()}")
ocs.registerOutParameter(1, OracleTypes.BFILE);
ocs.execute();
oracle.sql.BFILE bfile = ocs.getBFILE(1);

Passing BFILE Locators

To pass a BFILE locator to a prepared statement or callable statement (to update a BFILE locator, for example), you can use the generic setObject() method or you can cast the statement to OraclePreparedStatement or OracleCallableStatement and use the setOracleObject() or setBFILE() method. These methods take the parameter index and an oracle.sql.BFILE object as input.

Example: Passing a BFILE Locator to a Prepared Statement

You want to insert a BFILE locator into a table. Assume that you have an OraclePreparedStatement ops where the first parameter is a string (to designate a row number), its second parameter is a BFILE, and you have a valid oracle.sql.BFILE object (bfile). Input the BFILE to the prepared statement as follows:

OraclePreparedStatement ops =
(OraclePreparedStatement)conn.prepareStatement
     
("INSERT INTO my_bfile_table VALUES (?,?)");

     ops.setString(1,"one");
ops.setBFILE(2, bfile);
ops.execute();
    

Example: Passing a BFILE Locator to a Callable Statement

Passing a BFILE locator to a callable statement is similar to passing it to a prepared statement. In this case, the BFILE locator is passed to the myGetFileLength() procedure, which returns the BFILE length as a numeric value.

OracleCallableStatement cstmt =
      (OracleCallableStatement)
        conn.prepareCall ("begin ? := myGetFileLength (?); end;");
    try
    {
      cstmt.registerOutParameter (1, Types.NUMERIC);
      cstmt.setBFILE (2, bfile);
      cstmt.execute ();
      return cstmt.getLong (1);
    }
    finally
    {
      cstmt.close ();
    }
  }

Reading BFILE Data

To read BFILE data, you must first get the BFILE locator. You can get the locator from either a callable statement or a result set. "Getting BFILE Locators" describes this.

Once you obtain the locator, there are a number of methods that you can perform on the BFILE without opening it. For example, you can use the oracle.sql.BFILE methods fileExists() and isFileOpen() to determine whether the BFILE exists and if it is open. However, if you want to read and manipulate the data, you must open the BFILE. BFILE data is materialized as a Java stream. Operate on BFILEs from JDBC as follows:

• To read from a BFILE, use the getBinaryStream() method of an oracle.sql.BFILE object to retrieve the entire file as an input stream. This returns a java.io.InputStream class.

  As with any InputStream object, use one of the overloaded read() methods to read the file data and use the close() method when you finish.

  Notes: BFILEs are read-only. You cannot insert data or otherwise write to a BFILE. You cannot use JDBC to create a new BFILE.

Example: Reading BFILE Data

The following example uses the getBinaryStream() method of an oracle.sql.BFILE object to read BFILE data into a byte stream and then read the byte stream into a byte array. The example assumes that the BFILE has already been opened.

// Read BFILE data from a BFILE locator
Inputstream in = bfile.getBinaryStream();
byte[] byte_array = new byte{10};
int byte_read = in.read(byte_array);

Creating and Populating a BFILE Column

You create a BFILE column in a table with SQL statements and specify the location where the BFILE resides. The examples below assume that you have already created your Connection object conn and Statement object stmt.

Creating a BFILE Column in a New Table

To work with BFILE data, create a BFILE column in a table and specify the location of the BFILE. To specify the location of the BFILE, use the SQL CREATE DIRECTORY...AS statement to specify an alias for the directory where the BFILE resides. Then execute the statement. In this example, the directory alias is test_dir and the location where the BFILE resides is /home/work.

String cmd;
cmd = "CREATE DIRECTORY test_dir AS '/home/work'";
stmt.execute (cmd);

Use the SQL CREATE TABLE statement to create a table containing a BFILE column, then execute the statement. In this example, the name of the table is my_bfile_table.

// Create a table containing a BFILE field 
cmd = "CREATE TABLE my_bfile_table (x varchar2 (30), b bfile)";
stmt.execute (cmd);

In this example, the VARCHAR2 column designates a row number and the bfile column stores the locator of the BFILE data.

Populating a BFILE Column

Use the SQL INSERT INTO...VALUES statement to populate the VARCHAR2 and bfile fields, then execute the statement. The bfile column is populated with the locator to the BFILE data. To populate the BFILE column, use the bfilename keyword to specify the directory alias and the name of the BFILE file.

cmd ="INSERT INTO my_bfile_table VALUES ('one', bfilename(test_dir, 
                                         'file1.data'))";
stmt.execute (cmd);
cmd ="INSERT INTO my_bfile_table VALUES ('two', bfilename(test_dir,  
                                         'jdbcTest.data'))";
stmt.execute (cmd);

In this example, the name of the directory alias is test_dir. The locator of the BFILE file1.data is loaded into the bfile column on row one, and the locator of the BFILE jdbcTest.data is loaded into the bfile column on row two.

As an alternative, you might want to create the row for the row number and BFILE locator now, but wait until later to insert the locator. In this case, insert the row number into the table, and null as a place holder for the BFILE locator.

cmd ="INSERT INTO my_bfile_table VALUES ('three', null)";
stmt.execute(cmd);

Here, three is inserted into the row number column and null is inserted as the place holder. Later in your program, insert the BFILE locator into the table by using a prepared statement.

First get a valid BFILE locator into the bfile object:

rs = stmt.executeQuery("SELECT b FROM my_bfile_table WHERE x='two'");
    rs.next()
      oracle.sql.BFILE bfile = ((OracleResultSet)rs).getBFILE(2);

Then, create your prepared statement. Note that because this example uses the setBFILE() method to identify the BFILE, the prepared statement must be cast to an OraclePreparedStatement:

OraclePreparedStatement ops = 
(OraclePreparedStatement)conn.prepareStatement(INSERT ? INTO my_bfile_table) 
                 WHERE (x = 'three');
ops.setBFILE(2, bfile);
ops.execute();

Now row two and row three contain the same BFILE.

Once you have the BFILE locators available in a table, you can access and manipulate the BFILE data. The next section, "Accessing and Manipulating BFILE Data", describes this.

Accessing and Manipulating BFILE Data

Once you have the BFILE locator in a table, you can access and manipulate the data to which it points. To access and manipulate the data, you must first select its locator from a result set or a callable statement.

The following example gets the locator of the BFILE from row two of a table into a result set. The result set is cast to an OracleResultSet so that oracle.sql.* methods can be used on it. Several of the methods applied to the BFILE, such as getDirAlias() and getName(), do not require you to open the BFILE. Methods that manipulate the BFILE data, such as reading, getting the length, and displaying, do require you to open the BFILE.

When you finish manipulating the BFILE data, you must close the BFILE. For a complete BFILE example, see "BFILE Sample".

// select the bfile locator
cmd = "SELECT *  FROM my_bfile_table WHERE x = 'two'";
rset = stmt.executeQuery (cmd);

if (rset.next ())
    {
BFILE bfile = ((OracleResultSet)rset).getBFILE (2);

// for these methods, you do not have to open the bfile
println("getDirAlias() = " + bfile.getDirAlias());
println("getName() = " + bfile.getName());
println("fileExists() = " + bfile.fileExists());
println("isFileOpen() = " + bfile.isFileOpen());

// now open the bfile to get the data
bfile.openFile();

// get the BFILE data as a binary stream
InputStream in = bfile.getBinaryStream();
int length ;

// read the bfile data in 6-byte chunks
byte[] buf = new byte[6];

while ((length = in.read(buf)) != -1)
{
 
    // append and display the bfile data in 6-byte chunks 
   StringBuffer sb = new StringBuffer(length);
   for (int i=0; i<length; i++)
      sb.append( (char)buf[i] );
      println(sb.toString());
}

// we are done working with the input stream. Close it.   
in.close();

// we are done working with the BFILE. Close it.  
bfile.closeFile();

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