This article mainly shows you how to use JavaExcel API to read and write Excel files. With regard to the JavaExcel API, this is an open source lib library. The related feature s are as follows:

Supports Excel 95, 97, 2000, XP, 2003 tabulation pages.
Can read and write related Excel formulas (only support Excel 97 and later versions)
Excel 2000 format xls file can be generated.
Support font, number and date formats.
Supports cell shadows, borders and colors.
Existing tab pages can be modified.
International multilingual set. (Formulas currently supported, English, French, Spanish and German)
Supports chart copy.
Support the insertion and reproduction of pictures.
Logging can be generated using Jakarta Commons Logging, log4j, JDK 1.4 Logger, etc.
More...
You can download it here: http://jexcelapi.sourceforge.... Then, add jxl.jar to your Java classpath.

Here are two routines, one is how to create Excel, the other is how to read Excel.

Create Excel

package writer;
 
import java.io.File;
import java.io.IOException;
import java.util.Locale;
 
import jxl.CellView;
import jxl.Workbook;
import jxl.WorkbookSettings;
import jxl.format.UnderlineStyle;
import jxl.write.Formula;
import jxl.write.Label;
import jxl.write.Number;
import jxl.write.WritableCellFormat;
import jxl.write.WritableFont;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
import jxl.write.WriteException;
import jxl.write.biff.RowsExceededException;
 
 
public class WriteExcel {
 
    private WritableCellFormat timesBoldUnderline;
    private WritableCellFormat times;
    private String inputFile;
     
public void setOutputFile(String inputFile) {
    this.inputFile = inputFile;
    }
 
    public void write() throws IOException, WriteException {
        File file = new File(inputFile);
        WorkbookSettings wbSettings = new WorkbookSettings();
 
        wbSettings.setLocale(new Locale("en", "EN"));
 
        WritableWorkbook workbook = Workbook.createWorkbook(file, wbSettings);
        workbook.createSheet("Report", 0);
        WritableSheet excelSheet = workbook.getSheet(0);
        createLabel(excelSheet);
        createContent(excelSheet);
 
        workbook.write();
        workbook.close();
    }
 
    private void createLabel(WritableSheet sheet)
            throws WriteException {
        // Lets create a times font
        WritableFont times10pt = new WritableFont(WritableFont.TIMES, 10);
        // Define the cell format
        times = new WritableCellFormat(times10pt);
        // Lets automatically wrap the cells
        times.setWrap(true);
 
        // Create create a bold font with unterlines
        WritableFont times10ptBoldUnderline = new WritableFont(
                WritableFont.TIMES, 10, WritableFont.BOLD, false,
                UnderlineStyle.SINGLE);
        timesBoldUnderline = new WritableCellFormat(times10ptBoldUnderline);
        // Lets automatically wrap the cells
        timesBoldUnderline.setWrap(true);
 
        CellView cv = new CellView();
        cv.setFormat(times);
        cv.setFormat(timesBoldUnderline);
        cv.setAutosize(true);
 
        // Write a few headers
        addCaption(sheet, 0, 0, "Header 1");
        addCaption(sheet, 1, 0, "This is another header");
         
 
    }
 
    private void createContent(WritableSheet sheet) throws WriteException,
            RowsExceededException {
        // Write a few number
        for (int i = 1; i < 10; i++) {
            // First column
            addNumber(sheet, 0, i, i + 10);
            // Second column
            addNumber(sheet, 1, i, i * i);
        }
        // Lets calculate the sum of it
        StringBuffer buf = new StringBuffer();
        buf.append("SUM(A2:A10)");
        Formula f = new Formula(0, 10, buf.toString());
        sheet.addCell(f);
        buf = new StringBuffer();
        buf.append("SUM(B2:B10)");
        f = new Formula(1, 10, buf.toString());
        sheet.addCell(f);
 
        // Now a bit of text
        for (int i = 12; i < 20; i++) {
            // First column
            addLabel(sheet, 0, i, "Boring text " + i);
            // Second column
            addLabel(sheet, 1, i, "Another text");
        }
    }
 
    private void addCaption(WritableSheet sheet, int column, int row, String s)
            throws RowsExceededException, WriteException {
        Label label;
        label = new Label(column, row, s, timesBoldUnderline);
        sheet.addCell(label);
    }
 
    private void addNumber(WritableSheet sheet, int column, int row,
            Integer integer) throws WriteException, RowsExceededException {
        Number number;
        number = new Number(column, row, integer, times);
        sheet.addCell(number);
    }
 
    private void addLabel(WritableSheet sheet, int column, int row, String s)
            throws WriteException, RowsExceededException {
        Label label;
        label = new Label(column, row, s, times);
        sheet.addCell(label);
    }
 
    public static void main(String[] args) throws WriteException, IOException {
        WriteExcel test = new WriteExcel();
        test.setOutputFile("c:/temp/lars.xls");
        test.write();
        System.out
                .println("Please check the result file under c:/temp/lars.xls ");
    }
}

Read Excel

package reader;
 
import java.io.File;
import java.io.IOException;
 
import jxl.Cell;
import jxl.CellType;
import jxl.Sheet;
import jxl.Workbook;
import jxl.read.biff.BiffException;
 
public class ReadExcel {
 
    private String inputFile;
 
    public void setInputFile(String inputFile) {
        this.inputFile = inputFile;
    }
 
    public void read() throws IOException  {
        File inputWorkbook = new File(inputFile);
        Workbook w;
        try {
            w = Workbook.getWorkbook(inputWorkbook);
            // Get the first sheet
            Sheet sheet = w.getSheet(0);
            // Loop over first 10 column and lines
 
            for (int j = 0; j < sheet.getColumns(); j++) {
                for (int i = 0; i < sheet.getRows(); i++) {
                    Cell cell = sheet.getCell(j, i);
                    CellType type = cell.getType();
                    if (cell.getType() == CellType.LABEL) {
                        System.out.println("I got a label "
                                + cell.getContents());
                    }
 
                    if (cell.getType() == CellType.NUMBER) {
                        System.out.println("I got a number "
                                + cell.getContents());
                    }
 
                }
            }
        } catch (BiffException e) {
            e.printStackTrace();
        }
    }
 
    public static void main(String[] args) throws IOException {
        ReadExcel test = new ReadExcel();
        test.setInputFile("c:/temp/lars.xls");
        test.read();
    }
 
}