收藏——Java导出数据到excel保存在服务器及客户端下载

例子：（来自：http://www.iteye.com/problems/54701）

import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableCellFormat;
import jxl.write.WritableFont;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;

public class TestExcel {
private String driverClass = "net.sourceforge.jtds.jdbc.Driver";

    private String url ="jdbc:jtds:sqlserver:/localhost:1433/demo";

    private String user = "sa";

    private String password = "";

    private Connection connection;
public void exportClassroom(OutputStream os) {  

try {  
WritableWorkbook wbook = Workbook.createWorkbook(os); //建立excel文件  
WritableSheet wsheet = wbook.createSheet("报警记录表", 0); //工作表名称  
//设置Excel字体  
WritableFont wfont = new WritableFont(WritableFont.ARIAL, 16,  
WritableFont.BOLD, false,  
jxl.format.UnderlineStyle.NO_UNDERLINE,  
jxl.format.Colour.BLACK);  
WritableCellFormat titleFormat = new WritableCellFormat(wfont);  
String[] title = { "报警记录编号", "报警时间", "报警设备", "报警设备编号","报警事件名称","报警编号"};  
//设置Excel表头  
for (int i = 0; i < title.length; i++) {  
Label excelTitle = new Label(i, 0, title[i], titleFormat);  
wsheet.addCell(excelTitle);  
}  
int c = 1; //用于循环时Excel的行号  
Connection con=openConnection();
    Statement st=con.createStatement();
    String sql="select * from jlbjsj where BJJLSJ between '2010-09-01 08:19:25' and '2010-12-02 08:19:25' and BJSBMC like '%'";
ResultSet rs=st.executeQuery(sql); //这个是从数据库中取得要导出的数据  
while (rs.next()){
Label content1 = new Label(0, c, (String)rs.getString("BJJLBH"));  
Label content2 = new Label(1, c, (String)rs.getString("BJJLSJ"));  
Label content3 = new Label(2, c, (String)rs.getString("BJSBMC"));   
Label content4 = new Label(3, c, (String)rs.getString("BJSBBH"));
Label content5 = new Label(4, c, (String)rs.getString("BJBLMC"));
Label content6 = new Label(5, c, (String)rs.getString("BJBLBH"));
wsheet.addCell(content1);  
wsheet.addCell(content2);  
wsheet.addCell(content3);  
wsheet.addCell(content4);
wsheet.addCell(content5);
wsheet.addCell(content6);
c++;  
}  
wbook.write(); //写入文件  
wbook.close();  
os.close(); 
System.out.println("导入成功！");
} catch (Exception e) {  
e.printStackTrace(); 
}  

}

public Connection openConnection() throws SQLException {
        try {
            Class.forName(driverClass).newInstance();
            connection = DriverManager.getConnection(url, user, password); 
            return connection;
        } catch (Exception e) {
            throw new SQLException(e.getMessage());
        }
    }

    public void closeConnection() {
        try {        
            if (connection != null)
                connection.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //入口main方法
    public static void main(String[] args){
    TestExcel te=new TestExcel();
    File f=new File("d:\\kk.xls");
    try{
    f.createNewFile();
    OutputStream os=new FileOutputStream(f);
    te.exportClassroom(os);
    }catch(Exception e){
    e.printStackTrace();
    }

    }

}