Convert with Java methods

The Java™ methods getBytes(), getString(), InputStreamReader(), and OutputStreamWriter() take a code-set parameter that converts to and from Unicode and the specified code set.

Here is sample code that shows how to convert a file from the client code set to Unicode and then from Unicode to the database code set:
File infile = new File("data_jpn.dat");
File outfile = new File ("data_conv.dat");..
.pstmt = conn.prepareStatement("insert into t_text values (?)");..
.// Convert data from client encoding to database encoding
System.out.println("Converting data ...\n");
try
    {
    String from = "SJIS";
    String to = "8859_1";
    convert(infile, outfile, from, to);
    }
catch (Exception e)
    {
    System.out.println("Failed to convert file");
    }

System.out.println("Inserting data ...\n");
try
    {
    int fileLength = (int) outfile.length();
    fin = new FileInputStream(outfile);
    pstmt.setAsciiStream(1 , fin, fileLength);
    pstmt.executeUpdate();
    }
catch (Exception e)
    {
    System.out.println("Failed to setAsciiStream");
    }..
.public static void convert(File infile, File outfile, String from, String to) 
    throws IOException
    {
    InputStream in = new FileInputStream(infile);
    OutputStream out = new FileOutputStream(outfile);

    Reader r = new BufferedReader( new InputStreamReader( in, from));
    Writer w = new BufferedWriter( new OutputStreamWriter( out, to));

    //Copy characters from input to output. The InputStreamReader converts
    // from the input encoding to Unicode, and the OutputStreamWriter
    // converts from Unicode to the output encoding.  Characters that can
    // not be represented in the output encoding are output as '?'

    char[] buffer = new char[4096];
    int len;
    while ((len = r.read(buffer)) != -1)
        w.write(buffer, 0, len);
    r.close();
    w.flush();
    w.close();
    }

When you retrieve data from the database, you can use the same approach to convert the data from the database code set to the client code set.