JSP 后台导出Excel

主要的思想就是：先设置路径以及导出excel表格名字，要有一个模板excel（导出的excel表格是以这个为模板的，就是模板上基本的名字合并单元格都已经弄好了，我们只要进行插值就好了），然后通过一个类方法在模板上插值。

需要三个包：poi-3.0.2-FINAL-20080204.jar

poi-contrib-3.0.2-FINAL-20080204.jar

poi-scratchpad-3.0.2-FINAL-20080204.jar

excel类（最主要的功能类）

public void exportExcel(String s , int x , int y , OutputStream out) throws FileNotFoundException, IOException{
POIFSFileSystem	fs = new POIFSFileSystem(new FileInputStream("model/xcbg.xls"));
//这里是设置需要参考的模板excel，特别重要！一切的填写都是按照这个模板填写的，最后生成的excel也是按照这个模板生成的
//只不过比起模板，我们生成的新excel会加上我们自己的信息
HSSFWorkbook workbook = new HSSFWorkbook(fs);
HSSFSheet sheet = workbook.getSheetAt(0);
HSSFRow row = sheet.getRow(x-1);
//	HSSFCell cell = row.getCell((short)0);
HSSFCell cell = row.createCell((short)(y-1));
cell.setCellValue(s);
HSSFCellStyle cellStyle = cell.getCellStyle();
try{
workbook.write(out);//客户端下载该excel
}catch (IOException e) {
// TODO: handle exception
e.printStackTrace();
}
}
//这个方法是单独对一块没有规律的excel填写用的，s是填写的信息 ，例如 ：你好；x，y分别表示第几行第几列（不是从0开始）；out表示写入哪个文件里去。
//
public void exportExcelMain (int xStart , Collection<T> dataset ,
OutputStream out) throws FileNotFoundException, IOException{

POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream("model/xcbg.xls"));
HSSFWorkbook workbook = new HSSFWorkbook(fs);
HSSFSheet sheet = workbook.getSheetAt(0);

HSSFCellStyle cellStyle = workbook.createCellStyle();
HSSFDataFormat format = workbook.createDataFormat();
cellStyle.setDataFormat(format.getFormat("@"));
cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
cellStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
cellStyle.setWrapText(true);

System.out.println(xStart);

Iterator<T> it = dataset.iterator();
int index = 1;
while(it.hasNext()) {
index++;
HSSFRow row = sheet.getRow(xStart-1);
T t = (T) it.next();
Field[] fields = t.getClass().getDeclaredFields();
for(short i=0; i<fields.length; i++){
HSSFCell cell = row.createCell(i);
cell.setCellStyle(cellStyle);
Field field = fields[i];
String filedName = field.getName();
String getMethodName = "get" + filedName.substring(0,1).toUpperCase()
+ filedName.substring(1);
try{
Class tCls = t.getClass();
Method getMethod = tCls.getMethod(getMethodName, new Class[]{});
Object value = getMethod.invoke(t , new Object[]{});
String textValue = null;
textValue = value.toString();
if (textValue != null) {
Pattern p = Pattern.compile("^//d+(//.//d+)?{1}quot;");
Matcher matcher = p.matcher(textValue);
if (matcher.matches()) {
// 锟斤拷锟斤拷锟街碉拷锟斤拷double锟斤拷锟斤拷
cell.setCellValue(Double.parseDouble(textValue));
} else {
HSSFRichTextString richString = new HSSFRichTextString(
textValue);
HSSFFont font3 = workbook.createFont();
font3.setColor(HSSFColor.BLUE.index);
richString.applyFont(font3);
cell.setCellValue(richString);
}
}
}catch (SecurityException e) {
// TODO: handle exception
e.printStackTrace();
}catch (NoSuchMethodException e) {
// TODO: handle exception
e.printStackTrace();
}catch (IllegalArgumentException e) {
// TODO: handle exception
e.printStackTrace();
}catch (IllegalAccessException e) {
// TODO: handle exception
e.printStackTrace();
}catch (InvocationTargetException e) {
// TODO: handle exception
e.printStackTrace();
}
}
xStart++;

}
try{
workbook.write(out);
}catch (IOException e) {
// TODO: handle exception
e.printStackTrace();
}
}

如何调用上面的功能类？

如下：

public class FillXCBG{
public static void main(String[] args) {
excel<Xcbg> ex = new excel<Xcbg>();//这里需要特别注意！用到excel里的第二个方法时，dataset里装的哪个类，这里也是哪个类
int xStart = 8;
ArrayList<Xcbg> dataset = new ArrayList<Xcbg>();

dataset.add(new Xcbg("地fang",0,0,1,0,1,0,"处理方法","使用药物","建议"));
dataset.add(new Xcbg("网卡阿卡",0,0,1,0,1,0,"处理方法","使用药物","建议"));
try{
OutputStream out = new FileOutputStream("excel\\test.xls");//这里是确定你要生成的excel是在哪个目录下的，并且想要命名为什么
//这里表示的意思是：在new File().getAbsolutedPath()获取到的路径下的excel文件夹里的test.xls文件
ex.exportExcelMain(xStart, dataset , out);
//xStart是excel从第一行开始填写，然后根据dataset里面装的实体有几个属性填写该行里的几列（其中有一个是填充位，我也不知道干什么的）
//然后根据dataset有几个元素（实体）这里是add了几个Xcbg类对象 就填写几行

}catch(FileNotFoundException e){
e.printStackTrace();
}catch (IOException e) {
// TODO: handle exception
e.printStackTrace();
}
this.doPost(request, response);
}

下面再贴出一个综合上面两个大功能类的方法：

public void exportExcelMain (int xStart , Collection<T> dataset ,ArrayList<XcbgTitle> list,OutputStream out)
throws FileNotFoundException, IOException{
POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream("../webapps/Insecticide/WEB-INF/model/xcbg.xls"));
//		POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream("model/xcbg.xls"));
HSSFWorkbook workbook = new HSSFWorkbook(fs);
HSSFSheet sheet = workbook.getSheetAt(0);

for(int j = 0 ; j < list.size(); j ++){//这里面的就是之前excel的第一个填充不规则地区的方法，通过x，y坐标
HSSFRow row = sheet.getRow(list.get(j).getX()-1);//excel也是从0行0列开始的，我们给出来的都是从第一行第一列开始的
HSSFCell cell = row.createCell((short)(list.get(j).getY()-1));
cell.setCellValue(list.get(j).getString());
HSSFCellStyle cellStyle = cell.getCellStyle();
}
HSSFCellStyle cellStyle = workbook.createCellStyle();
HSSFDataFormat format = workbook.createDataFormat();
cellStyle.setDataFormat(format.getFormat("@"));
cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
cellStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
cellStyle.setWrapText(true);

Iterator<T> it = dataset.iterator();
int index = 1;
while(it.hasNext()) {
index++;
HSSFRow row = sheet.getRow(xStart-1);
T t = (T) it.next();
Field[] fields = t.getClass().getDeclaredFields();
for(short i=0; i<fields.length; i++){
HSSFCell cell = row.createCell(i);
cell.setCellStyle(cellStyle);
Field field = fields[i];
String filedName = field.getName();
String getMethodName = "get" + filedName.substring(0,1).toUpperCase()
+ filedName.substring(1);
try{
Class tCls = t.getClass();
Method getMethod = tCls.getMethod(getMethodName, new Class[]{});
Object value = getMethod.invoke(t , new Object[]{});
String textValue = null;
textValue = value.toString();
if (textValue != null) {
Pattern p = Pattern.compile("^//d+(//.//d+)?{1}quot;");
Matcher matcher = p.matcher(textValue);
if (matcher.matches()) {
// �����ֵ���double����
cell.setCellValue(Double.parseDouble(textValue));
} else {
HSSFRichTextString richString = new HSSFRichTextString(
textValue);
HSSFFont font3 = workbook.createFont();
font3.setColor(HSSFColor.BLUE.index);
richString.applyFont(font3);
cell.setCellValue(richString);
}
}
}catch (SecurityException e) {
// TODO: handle exception
e.printStackTrace();
}catch (NoSuchMethodException e) {
// TODO: handle exception
e.printStackTrace();
}catch (IllegalArgumentException e) {
// TODO: handle exception
e.printStackTrace();
}catch (IllegalAccessException e) {
// TODO: handle exception
e.printStackTrace();
}catch (InvocationTargetException e) {
// TODO: handle exception
e.printStackTrace();
}
}
xStart++;
}
try{
workbook.write(out);
}catch (IOException e) {
// TODO: handle exception
e.printStackTrace();
}
}
public void createExcel(OutputStream out) throws IOException{
POIFSFileSystem	fs = new POIFSFileSystem(new FileInputStream("model/xcbg.xls"));
HSSFWorkbook workbook = new HSSFWorkbook(fs);
try{
workbook.write(out);
}catch (IOException e) {
// TODO: handle exception
e.printStackTrace();
}
}