怎么用<em>java</em>把数据库里的数据写入到excel表中-java excel写入,

java 读excel 还是比较方便简单的，原理就是，先用java 读取excel，然后，一行行的写入数据库，字段的话，你自己程序里面写就行了，给你个例子：
从Excel读取数据,生成新的Excel，以及修改Excel
package common.util;

import jxl.*;
import jxl.format.UnderlineStyle;
import jxl.write.*;
import jxl.write.Number;
import jxl.write.Boolean;

import java.io.*;

/**
* Created by IntelliJ IDEA.
* User: xl
* Date: 2005-7-17
* Time: 9:33:22
* To change this template use File | Settings | File Templates.
*/
public class ExcelHandle
{
public ExcelHandle()
{
}

/**
* 读取Excel
*
* @param filePath
*/
public static void readExcel(String filePath)
{
try
{
InputStream is = new FileInputStream(filePath);
Workbook rwb = Workbook.getWorkbook(is);
//Sheet st = rwb.getSheet("0")这里有两种方法获取sheet表,1为名字，而为下标，从0开始
Sheet st = rwb.getSheet("original");
Cell c00 = st.getCell(0,0);
//通用的获取cell值的方式,返回字符串
String strc00 = c00.getContents();
//获得cell具体类型e799bee5baa6e79fa5e98193e4b893e5b19e331值的方式
if(c00.getType() == CellType.LABEL)
{
LabelCell labelc00 = (LabelCell)c00;
strc00 = labelc00.getString();
}
//输出
System.out.println(strc00);
//关闭
rwb.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}

/**
* 输出Excel
*
* @param os
*/
public static void writeExcel(OutputStream os)
{
try
{
/**
* 只能通过API提供的工厂方法来创建Workbook，而不能使用WritableWorkbook的构造函数，
* 因为类WritableWorkbook的构造函数为protected类型
* method(1)直接从目标文件中读取WritableWorkbook wwb = Workbook.createWorkbook(new File(targetfile));
* method(2)如下实例所示 将WritableWorkbook直接写入到输出流

*/
WritableWorkbook wwb = Workbook.createWorkbook(os);
//创建Excel工作表 指定名称和位置
WritableSheet ws = wwb.createSheet("Test Sheet 1",0);

//**************往工作表中添加数据*****************

//1.添加Label对象
Label label = new Label(0,0,"this is a label test");
ws.addCell(label);

//添加带有字型Formatting对象
WritableFont wf = new WritableFont(WritableFont.TIMES,18,WritableFont.BOLD,true);
WritableCellFormat wcf = new WritableCellFormat(wf);
Label labelcf = new Label(1,0,"this is a label test",wcf);
ws.addCell(labelcf);

//添加带有字体颜色的Formatting对象
WritableFont wfc = new WritableFont(WritableFont.ARIAL,10,WritableFont.NO_BOLD,false,
UnderlineStyle.NO_UNDERLINE,jxl.format.Colour.RED);
WritableCellFormat wcfFC = new WritableCellFormat(wfc);
Label labelCF = new Label(1,0,"This is a Label Cell",wcfFC);
ws.addCell(labelCF);

//2.添加Number对象
Number labelN = new Number(0,1,3.1415926);
ws.addCell(labelN);

//添加带有formatting的Number对象
NumberFormat nf = new NumberFormat("#.##");
WritableCellFormat wcfN = new WritableCellFormat(nf);
Number labelNF = new jxl.write.Number(1,1,3.1415926,wcfN);
ws.addCell(labelNF);

//3.添加Boolean对象
Boolean labelB = new jxl.write.Boolean(0,2,false);
ws.addCell(labelB);

//4.添加DateTime对象
jxl.write.DateTime labelDT = new jxl.write.DateTime(0,3,new java.util.Date());
ws.addCell(labelDT);

//添加带有formatting的DateFormat对象
DateFormat df = new DateFormat("dd MM yyyy hh:mm:ss");
WritableCellFormat wcfDF = new WritableCellFormat(df);
DateTime labelDTF = new DateTime(1,3,new java.util.Date(),wcfDF);
ws.addCell(labelDTF);

//添加图片对象,jxl只支持png格式图片
File image = new File("f:\\2.png");
WritableImage wimage = new WritableImage(0,1,2,2,image);
ws.addImage(wimage);
//写入工作表
wwb.write();
wwb.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}

/**
* 拷贝后,进行修改,其中file1为被copy对象，file2为修改后创建的对象
* 尽单元格原有的格式化修饰是不能去掉的，我们还是可以将新的单元格修饰加上去，
* 以使单元格的内容以不同的形式表现
* @param file1
* @param file2
*/
public static void modifyExcel(File file1,File file2)
{
try
{
Workbook rwb = Workbook.getWorkbook(file1);
WritableWorkbook wwb = Workbook.createWorkbook(file2,rwb);//copy
WritableSheet ws = wwb.getSheet(0);
WritableCell wc = ws.getWritableCell(0,0);
//判断单元格的类型,做出相应的转换
if(wc.getType == CellType.LABEL)
{
Label label = (Label)wc;
label.setString("The value has been modified");
}
wwb.write();
wwb.close();
rwb.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}
public void export(List<PSbLnode> li, String dateString,String[] title) throws WriteException, IOException {
// 准备设置excel工作表的标题
// 创建Excel工作薄
WritableWorkbook wwb = null;
try {

// 输出的excel的路径
String filePath1 = Const.pathStr+Const.pathStr4+Const.pathStr3;
File file = new File(filePath1);
if(!file.exists()){
file.mkdir();
}
String filePath=filePath1+Const.pathStr4+Const.pathStr6+dateString+Const.pathStr5;
// 新建立一个jxl文件,即在C盘下生成testJXL.xls
OutputStream os = new FileOutputStream(filePath);
wwb = Workbook.createWorkbook(os);
// 添加第一个工作表并设置第一个Sheet的名字
WritableSheet sheet = wwb.createSheet("设备清单", 0);
Label label;
for (int i = 0; i < title.length; i++) {
// Label(x,y,z) 代表单元636f7079e799bee5baa6e79fa5e98193362格的第x+1列，第y+1行, 内容z
// 在Label对象的子对象中指明单元格的位置和内容
label = new Label(i, 0, title[i]);
// 将定义好的单元格添加到工作表中
sheet.addCell(label);
}
for (int i = 0; i < li.size(); i++) {
int j = 0;
j = i + 1;
//填充单元格
//获取区域名称
label = new Label(0, j, li.get(i).getQyName());
sheet.addCell(label);
//获取区域名称
label = new Label(1, j, li.get(i).getJzName());
sheet.addCell(label);
//获取设备名称
label = new Label(2, j, li.get(i).getLnodeName());
sheet.addCell(label);
// //获取设备类型名称
label = new Label(3, j, li.get(i).getSbxh());
sheet.addCell(label);
//获取运行状态
label = new Label(4, j, li.get(i).getYxzh());
sheet.addCell(label);
//获取删除状态
label = new Label(5, j, li.get(i).getDeleteFlag());
sheet.addCell(label);
//获取启用状态
label = new Label(6, j, li.get(i).getQyzt());
sheet.addCell(label);
//获取设备投运日期
label = new Label(7, j, li.get(i).getSbtyri());
sheet.addCell(label);
//获取使用年限
jxl.write.Number numb1 = new jxl.write.Number(8, j, li.get(i).getSynx());
sheet.addCell(numb1);
//获取区域名称
label = new Label(9, j, li.get(i).getAddUser());
sheet.addCell(label);
//获取区域名称
label = new Label(10, j, li.get(i).getUpdUser());
sheet.addCell(label);
//获取区域名称
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String newdate = sdf.format(li.get(i).getUpdTime());
label = new Label(11, j, newdate);
sheet.addCell(label);
//获取区域名称
SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd");
String newdate2 = sdf2.format(li.get(i).getAddTime());
label = new Label(12, j, newdate2);
sheet.addCell(label);
//获取区域名称
label = new Label(13, j, li.get(i).getZcbh());
sheet.addCell(label);
//获取区域名称
label = new Label(14, j, li.get(i).getSbcs());
sheet.addCell(label);
//获取区域名称
jxl.write.Number numb2 = new jxl.write.Number(15, j, li.get(i)
.getSbll());
sheet.addCell(numb2);
//获取区域名称
label = new Label(16, j, li.get(i).getRldw());
sheet.addCell(label);
//获取区域名称
label = new Label(17, j, li.get(i).getWxghjl());
sheet.addCell(label);
}
// 写入数据
wwb.write();
} catch (Exception e) {
e.printStackTrace();
}finally{
// 关闭文件
wwb.close();
}
}

Const文件：
/**路径：C盘*/
public static String pathStr = "C:";
/**路径：//*/
public static String pathStr2 = "//";
/**文件夹：workspace*/
public static String pathStr3 = "exportFile";
/**文件名：world*/
public static String pathStr6 = "Equipment";
/**路径：/*/
public static String pathStr4 = "/";
/**路径：.xls*/
public static String pathStr5 = ".xls";

添加Spire.Xls.jar依赖，可以创建Excel, 或者对现有Excel文档进行处理。

1. 写入数据到指定单元格

//Create a Workbook instance
Workbook wb = new Workbook();
//Get the first worksheet
Worksheet sheet = wb.getWorksheets().get(0);
//Write text in the specific cell
sheet.getCellRange(1,1).setText("Hello World");
//Save the file
wb.saveToFile("Hello World.xlsx", ExcelVersion.Version2016)

2. 将数组导入e69da5e6ba90e799bee5baa6e997aee7ad94338Excel

//Create a Workbook instance
Workbook wb = new Workbook();
//Get the first worksheet
Worksheet sheet = wb.getWorksheets().get(0);
//Insert an array to the first column (false if you want to insert data horizontally)
String[] stringArray = new String[]{"Apple","Pear","Grape","Banana","Peach"}
sheet.insertArray(stringArray,1,1,true);
//Save the file
wb.saveToFile("InsertArray.xlsx", ExcelVersion.Version2016);