I believe excel export function, is one of the essential functions of reporting, the last few days, I also spent a lot of thought to write this feature, now out to share with you, but also a summary of their own.
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1. First need to write a tool to export excel class.
public class ExcelUtil{
public static String NO_DEFINE = "no_define";//未定义的字段
public static String DEFAULT_DATE_PATTERN="yyyy年MM月dd日";//默认日期格式
public static int DEFAULT_COLOUMN_WIDTH = 17;
/**
* 导出Excel 97(.xls)格式 ，少量数据
* @param title 标题行
* @param headMap 属性-列名
* @param jsonArray 数据集
* @param datePattern 日期格式，null则用默认日期格式
* @param colWidth 列宽 默认 至少17个字节
* @param out 输出流
*/
public static void exportExcel(String title,Map<String, String> headMap,JSONArray jsonArray,String datePattern,int colWidth, OutputStream out) {
if(datePattern==null) datePattern = DEFAULT_DATE_PATTERN;
// 声明一个工作薄
HSSFWorkbook workbook = new HSSFWorkbook();
//表头样式
HSSFCellStyle titleStyle = workbook.createCellStyle();
titleStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
HSSFFont titleFont = workbook.createFont();
titleFont.setFontHeightInPoints((short) 20);
titleFont.setBoldweight((short) 700);
titleStyle.setFont(titleFont);
// 列头样式
HSSFCellStyle headerStyle = workbook.createCellStyle();
headerStyle.setFillBackgroundColor((short) 131);
headerStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
headerStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
headerStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
headerStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
headerStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
HSSFFont headerFont = workbook.createFont();
headerFont.setFontHeightInPoints((short) 12);
headerFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
headerStyle.setFont(headerFont);
// 单元格样式
HSSFCellStyle cellStyle = workbook.createCellStyle();
cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
cellStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
HSSFFont cellFont = workbook.createFont();
cellFont.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
cellStyle.setFont(cellFont);
// 生成一个(带标题)表格
HSSFSheet sheet = workbook.createSheet();
// 声明一个画图的顶级管理器
HSSFPatriarch patriarch = sheet.createDrawingPatriarch();
// 定义注释的大小和位置,详见文档
HSSFComment comment = patriarch.createComment(new HSSFClientAnchor(0,
0, 0, 0, (short) 4, 2, (short) 6, 5));
// 设置注释内容
comment.setString(new HSSFRichTextString("可以在POI中添加注释！"));
// 设置注释作者，当鼠标移动到单元格上是可以在状态栏中看到该内容.
comment.setAuthor("JACK");
//设置列宽
int minBytes = colWidth<DEFAULT_COLOUMN_WIDTH?DEFAULT_COLOUMN_WIDTH:colWidth;//至少字节数
int[] arrColWidth = new int[headMap.size()];
// 产生表格标题行,以及设置列宽
String[] properties = new String[headMap.size()];
String[] headers = new String[headMap.size()];
int ii = 0;
for (Iterator<String> iter = headMap.keySet().iterator(); iter
.hasNext();) {
String fieldName = iter.next();
properties[ii] = fieldName;
headers[ii] = headMap.get(fieldName);
int bytes = fieldName.getBytes().length;
arrColWidth[ii] = bytes < minBytes ? minBytes : bytes;
sheet.setColumnWidth(ii,arrColWidth[ii]*256);
ii++;
}
// 遍历集合数据，产生数据行
int rowIndex = 0;
for (int m=0;m<jsonArray.size();m++) {
JSONObject jo = jsonArray.getJSONObject(m);
if(rowIndex == 65535 || rowIndex == 0){
if ( rowIndex != 0 ) sheet = workbook.createSheet();//如果数据超过了，则在第二页显示
if(title!=null&&!"".equals(title)&&!"null".equals(title)){
HSSFRow titleRow = sheet.createRow(0);//表头 rowIndex=0
titleRow.createCell(0).setCellValue(title);
titleRow.getCell(0).setCellStyle(titleStyle);
sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, headMap.size() - 1));
}
HSSFRow headerRow = sheet.createRow(1); //列头 rowIndex =1
for(int i=0;i<headers.length;i++)
{
headerRow.createCell(i).setCellValue(headers[i]);
headerRow.getCell(i).setCellStyle(headerStyle);
}
rowIndex = 2;//数据内容从 rowIndex=2开始
}
HSSFRow dataRow = sheet.createRow(rowIndex);
for (int i = 0; i < properties.length; i++)
{
HSSFCell newCell = dataRow.createCell(i);
Object o = jo.get(properties[i]);
String cellValue = "";
if(o==null) cellValue = "";
else if(o instanceof Date) cellValue = new SimpleDateFormat(datePattern).format(o);
else cellValue = o.toString();
newCell.setCellValue(cellValue);
newCell.setCellStyle(cellStyle);
}
rowIndex++;
}
// 自动调整宽度
/*for (int i = 0; i < headers.length; i++) {
sheet.autoSizeColumn(i);
}*/
try {
workbook.write(out);
workbook = null;
} catch (IOException e) {
e.printStackTrace();
}
}
//Web 导出excel
/**
* title
* - Excel的表头标题
* fileName
* - 文件名
*/
public static void downloadExcelFile(String title,String fileName,Map<String,String> headMap,JSONArray ja,HttpServletResponse response){
try {
ByteArrayOutputStream os = new ByteArrayOutputStream();
ExcelUtil.exportExcel(title,headMap,ja,null,0,os);
byte[] content = os.toByteArray();
InputStream is = new ByteArrayInputStream(content);
// 设置response参数，可以打开下载页面
response.reset();
response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-8");
response.setHeader("Content-Disposition", "attachment;filename="+ new String((fileName + ".xls").getBytes(), "iso-8859-1"));
response.setContentLength(content.length);
ServletOutputStream outputStream = response.getOutputStream();
BufferedInputStream bis = new BufferedInputStream(is);
BufferedOutputStream bos = new BufferedOutputStream(outputStream);
byte[] buff = new byte[8192];
int bytesRead;
while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
bos.write(buff, 0, bytesRead);
}
bis.close();
bos.close();
outputStream.flush();
outputStream.close();
}catch (Exception e) {
e.printStackTrace();
}
}
}——————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————
2. tools is to use the tools of the future written.
As can be seen, this method of deriving utility class called excel downloadExcelFile (String title, String fileName, Map <String, String> headMap, JSONArray ja, HttpServletResponse response);
It requires the incoming parameters are String, string, map, jsonarray and a response;
The first string title, you can not write directly to write null.
The second string is the name of the downloaded file.
The third map is set and the header fields you want to set the incoming excel.
The fourth jsonarr you of incoming data json.
The fifth is the response.
I frame is used temporarily ssh, so there is acton, as follows.
public String exportWorkExcel() throws Exception {
//
String dateformat = "yyyy-MM-dd HH:mm:ss";
//生成一个按时间格式的文件名
String fileformat = "yyyyMMddHHmmss";
SimpleDateFormat sf = new SimpleDateFormat(fileformat);
Calendar cal = Calendar.getInstance();
String filename = (String)getRequest().getParameter("exportfilename");
if(filename==null){
filename = "";
}
filename += "_" + sf.format(cal.getTime());
//·······································································
//得到你想要打印的表格的list集合。
//例如list<Work> list;
//········································································
Map<String, String> headMap = new LinkedHashMap<String, String>();
headMap.put("workname", "文号");
//```````````````````````````````````````````````````````````````````````
//设计你的excel的表头和对应的字段
//·······································································
JSONArray arr = new JSONArray();
if(list!=null&&list.size()>0){
for(Work hw:list){
//把属性以键值对的形式放到map中
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
LinkedHashMap<String, String> ss = new LinkedHashMap<String, String>();
ss.put("workname", hw.getWorkName());
//······································································································
//把map转换成json对象，并且添加到jsonarr中
//·······································································································
JSONObject jsonObj = JSONObject.fromObject(ss);
arr.add(jsonObj);
}
/***********如果找到list装有一个完整的实体类，可以直接调用下面这个方法，便可以直接得到对应的jsonarr*******************/
/*arr = JsonBeanUtil.beanListToJsonArray(renotList,dateformat);*/
}
ExcelUtil.downloadExcelFile(null,filename, headMap, arr, getResponse());
return null;
}
3. This method is called the front, you're done! ! ! !
Note: jar package I use is poi1, if a higher version of poi some tools field in a class may not be the same, only you need to change the inside of the field before it.
