package com.zkbj.poi;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class DBConnection {private final String DBUrl = "jdbc:mysql://localhost:3306/****";   //1.修改数据库名private final String DBDriver = "com.mysql.jdbc.Driver";private final String username = "**"; 　　　　　　　　　　　　　　　　　　//2.修改成你的MySql登录名和密码private final String password = "***";private Connection con;public DBConnection() {try {Class.forName(DBDriver);con = DriverManager.getConnection(DBUrl, username, password);} catch (Exception e) {// TODO Auto-generated catch block
            e.printStackTrace();}}public Connection getDB() {return con;}public void closeDb(ResultSet rs, PreparedStatement ps) {if (rs != null) {try {rs.close();} catch (SQLException e) {// TODO Auto-generated catch block
e.printStackTrace();}}if (ps != null) {try {ps.close();} catch (SQLException e) {// TODO Auto-generated catch block
                e.printStackTrace();}}}
}

package com.zkbj.poi;import java.io.FileOutputStream;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;public class ProductDirExcel {public ProductDirExcel() throws Exception {Connection con = null;DBConnection db = new DBConnection();con = db.getDB();String sql = "select * from productdir";ResultSet rs = con.createStatement().executeQuery(sql);// 获取总列数int CountColumnNum = rs.getMetaData().getColumnCount();int i = 1;// 创建Excel文档HSSFWorkbook wb = new HSSFWorkbook();// sheet 对应一个工作页HSSFSheet sheet = wb.createSheet("productdir表中的数据");  //3.修改成你的SheetHSSFRow firstrow = sheet.createRow(0); // 下标为0的行开始HSSFCell[] firstcell = new HSSFCell[CountColumnNum];String[] names = new String[CountColumnNum];names[0] = "产品ID";                                     //4.修改成你的数据库数据名称。names[1] = "产品名称";names[2] = "产品版本";names[3] = "产品备注";names[4] = "产品分类ID";for (int j = 0; j < CountColumnNum; j++) {firstcell[j] = firstrow.createCell((short) j);firstcell[j].setCellValue(new HSSFRichTextString(names[j]));}while (rs.next()) {// 创建电子表格的一行HSSFRow row = sheet.createRow(i); // 下标为1的行开始for (int j = 0; j < CountColumnNum; j++) {// 在一行内循环HSSFCell cell = row.createCell((short) j);// 设置表格的编码集，使支持中文// // 先判断数据库中的数据类型// 将结果集里的值放入电子表格中cell.setCellValue(new HSSFRichTextString(rs.getString(j + 1)));}i++;}// 创建文件输出流，准备输出电子表格OutputStream out = new FileOutputStream("D:\\productdir.xls");            //5.修改成你创建Excel路径 并有这个文件展示数据wb.write(out);out.close();System.out.println("数据库导出成功");rs.close();con.close();}public static void main(String[] args) {try {@SuppressWarnings("unused")ProductDirExcel excel = new ProductDirExcel();} catch (Exception e) {// TODO Auto-generated catch block
            e.printStackTrace();}}
}