Java实现Excel导入数据库，数据库中的数据导入到Excel

package com.javen.service;

import java.io.File;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import jxl.Sheet;
import jxl.Workbook;

import com.javen.db.DBhepler;
import com.javen.entity.StuEntity;

/**
 * @author Javen
 * @Email zyw205@gmail.com
 * 
 */
public class StuService {
    /**
     * 查询stu表中所有的数据
     * @return 
     */
    public static List<StuEntity> getAllByDb(){
        List<StuEntity> list=new ArrayList<StuEntity>();
        try {
            DBhepler db=new DBhepler();
            String sql="select * from stu";
            ResultSet rs= db.Search(sql, null);
            while (rs.next()) {
                int id=rs.getInt("id");
                String name=rs.getString("name");
                String sex=rs.getString("sex");
                int num=rs.getInt("num");
                
                //System.out.println(id+" "+name+" "+sex+ " "+num);
                list.add(new StuEntity(id, name, sex, num));
            }
            
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return list;
    }
    
    /**
     * 查询指定目录中电子表格中所有的数据
     * @param file 文件完整路径
     * @return
     */
    public static List<StuEntity> getAllByExcel(String file){
        List<StuEntity> list=new ArrayList<StuEntity>();
        try {
            Workbook rwb=Workbook.getWorkbook(new File(file));
            Sheet rs=rwb.getSheet("Test Shee 1");//或者rwb.getSheet(0)
            int clos=rs.getColumns();//得到所有的列
            int rows=rs.getRows();//得到所有的行
            
            System.out.println(clos+" rows:"+rows);
            for (int i = 1; i < rows; i++) {
                for (int j = 0; j < clos; j++) {
                    //第一个是列数，第二个是行数
                    String id=rs.getCell(j++, i).getContents();//默认最左边编号也算一列 所以这里得j++
                    String name=rs.getCell(j++, i).getContents();
                    String sex=rs.getCell(j++, i).getContents();
                    String num=rs.getCell(j++, i).getContents();
                    
                    System.out.println("id:"+id+" name:"+name+" sex:"+sex+" num:"+num);
                    list.add(new StuEntity(Integer.parseInt(id), name, sex, Integer.parseInt(num)));
                }
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        return list;
        
    }
    
    /**
     * 通过Id判断是否存在
     * @param id
     * @return
     */
    public static boolean isExist(int id){
        try {
            DBhepler db=new DBhepler();
            ResultSet rs=db.Search("select * from stu where id=?", new String[]{id+""});
            if (rs.next()) {
                return true;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return false;
    }
    
    public static void main(String[] args) {
        /*List<StuEntity> all=getAllByDb();
        for (StuEntity stuEntity : all) {
            System.out.println(stuEntity.toString());
        }*/
        
        System.out.println(isExist(1));
        
    }
    
}

package com.javen.excel;

import java.io.File;
import java.util.List;

import com.javen.entity.StuEntity;
import com.javen.service.StuService;

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

public class TestDbToExcel {

    public static void main(String[] args) {
        try {
            WritableWorkbook wwb = null;
             
               // 创建可写入的Excel工作簿
               String fileName = "D://book.xls";
               File file=new File(fileName);
               if (!file.exists()) {
                   file.createNewFile();
               }
               //以fileName为文件名来创建一个Workbook
               wwb = Workbook.createWorkbook(file);

               // 创建工作表
               WritableSheet ws = wwb.createSheet("Test Shee 1", 0);
               
               //查询数据库中所有的数据
               List<StuEntity> list= StuService.getAllByDb();
               //要插入到的Excel表格的行号，默认从0开始
               Label labelId= new Label(0, 0, "编号(id)");//表示第
               Label labelName= new Label(1, 0, "姓名(name)");
               Label labelSex= new Label(2, 0, "性别(sex)");
               Label labelNum= new Label(3, 0, "薪水(num)");
               
               ws.addCell(labelId);
               ws.addCell(labelName);
               ws.addCell(labelSex);
               ws.addCell(labelNum);
               for (int i = 0; i < list.size(); i++) {
                   
                   Label labelId_i= new Label(0, i+1, list.get(i).getId()+"");
                   Label labelName_i= new Label(1, i+1, list.get(i).getName());
                   Label labelSex_i= new Label(2, i+1, list.get(i).getSex());
                   Label labelNum_i= new Label(3, i+1, list.get(i).getNum()+"");
                   ws.addCell(labelId_i);
                   ws.addCell(labelName_i);
                   ws.addCell(labelSex_i);
                   ws.addCell(labelNum_i);
               }
             
              //写进文档
               wwb.write();
              // 关闭Excel工作簿对象
               wwb.close();
             
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
    }
}