java后台导出excel（笔记记录）
//调用方法，可以用请求的方式，用postman可以模拟页面的下载文件场景
public static void main (String args[]){
excelHelper.setXls(导出的数据);
//编辑好报表的属性名，这个就是导出后顺序哦
String queryConText = "序号,发电户号,授权协议编号,授权协议版本号,签订渠道,签约完成状态,用户签订时间,授权协议 类型,维护时间 _#,powerGenerationNo,dealId,dealNum,dealDitch,signType,signDate,dealType,timeStamp";
excelHelper.dto2Excel(fileName, 报表的唯一标识, HttpServletResponse, queryConText);
}
public class ExcelHelper {
//存入需要导出的数据
private List xls;
public void setXls(List xls) {
this.xls = xls;
}
//private static final Logger logger = Logger.getLogger(ExcelHelper.class);
/**
* wangyf
*
* 导出Excel方法
*
*/
@SuppressWarnings("deprecation")
public void dto2Excel(String outfileName, String sheetName, HttpServletResponse response, String queryConText) {
HSSFWorkbook hwb = null;
OutputStream out = null;
String excelHead = null;
String excelValue = null;
String[] excelName = null;
String[] excelValueText = null;
String[] conText = null;
try {
if (!queryConText.isEmpty()&&queryConText!=null) {
conText = queryConText.split("_");
excelHead = conText[0];
excelValue = conText[1];
}
excelName = excelHead.split(",");
excelValueText = excelValue.split(",");
// 获取总列数
int CountColumnNum = excelName.length;
// 创建Excel文档
hwb = new HSSFWorkbook();
Object xlsDto = null;
// sheet 对应一个工作页
HSSFSheet sheet = hwb.createSheet(sheetName);//导出文件
HSSFRow firstrow = sheet.createRow(0); // 下标为0的行开始
HSSFCellStyle headstyle = hwb.createCellStyle();//设置样式
HSSFFont headfont = hwb.createFont();//设置字体
HSSFCell[] firstcell = new HSSFCell[CountColumnNum];
HSSFRichTextString ts = null;
HSSFFont font = null;
for (int i = 0, len = CountColumnNum; i < len; i++) {
font = (HSSFFont) hwb.createFont();
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD); // 宽度
firstcell[i] = firstrow.createCell(i);
ts = new HSSFRichTextString(excelName[i]);
ts.applyFont(font);
firstcell[i].setCellValue(ts);
}
//设置列的长度
setColumnWidth(excelName, sheet);
//设置字体
headfont.setFontName("黑体");
headfont.setFontHeightInPoints((short) 22);// 字体大小
headfont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);// 加粗
//设置样式
headstyle.setFont(headfont);
headstyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);// 左右居中
headstyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);// 上下居中
headstyle.setLocked(true);
headstyle.setWrapText(true);// 自动换行
HSSFRow row = null;
String value = "";
for (int i = 0, len = xls.size(); i < len; i++) {
// 创建一行
row = sheet.createRow(i + 1);
// 得到要插入的每一条记录
xlsDto = xls.get(i);
for (int colu = 0, _len = CountColumnNum; colu < _len; colu++) {
// 在一行内循环
HSSFCell cell = row.createCell(colu);
String filedName = excelValueText[colu];
if (filedName.equals("#")) {
value = (i + 1) + "";
} else {
value = findMethodByFieldName(filedName, xlsDto.getClass().getName(), xlsDto);
if ("null".equals(value)) {
value = "";
}
}
cell.setCellValue(value);
}
}
// 创建文件输出流，准备输出电子表格
// 清空response
response.reset();
// 设置response的Header
//response.addHeader("Content-Disposition", "attachment;filename=" + new String(outfileName.getBytes("UTF-8"),"ISO-8859-1"));
// response.addHeader("Content-Length", "" + file.length());
//response.setCharacterEncoding("UTF-8");
//response.setContentType("application/octet-stream;charset=utf-8");
//设置请求头，防止输出文件内容乱码
response.setContentType("application/vnd.ms-excel;charset=UTF-8");
response.setCharacterEncoding("UTF-8");
response.addHeader("Content-Disposition", "attachment;filename=" + new String(outfileName.getBytes("gb2312"), "ISO-8859-1") + ".xls");
out = new BufferedOutputStream(response.getOutputStream());
hwb.write(out);
// logger.info("数据库导出成功");
} catch (Exception e) {
// logger.error("报表生成xls异常！"+e.getMessage());
} finally {
if (out != null) {
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/* if (hwb != null) {
try {
hwb.cl
} catch (IOException e) {
e.printStackTrace();
}
}*/
}
}
public String findMethodByFieldName(String name, String className, Object obj) {
String result = "";
try {
Method[] ms = Class.forName(className).getMethods();
for (Method method : ms) {
if (method.getName().equals(findKey(name))) {
// 如果是时间类型
if (method.getReturnType().equals(Date.class)) {
String timeFormat = AnnotationUtil.findExcelFormartByfileName(name, obj);
java.text.DateFormat format1 = new java.text.SimpleDateFormat(timeFormat);
Date date = (Date) method.invoke(obj);
if (date != null) {
result = format1.format(date);
}
} else {
result = String.valueOf(method.invoke(obj));
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
public String findKey(String fieldName) {
String method = "";
method += "get";
//把第一个字符转为大写
method += fieldName.substring(0, 1).toUpperCase();
//取第一行字符后的
method += fieldName.substring(1);
return method;
}
//设置xls字段在文件中占多大区间，根据中文属性名的长度来设置区间长度，我这里写的比较low，大家可以参考下！
public void setColumnWidth(String[] excelName,HSSFSheet sheet) {
for (int i = 0; i < excelName.length; i++) {
if(excelName[i].length()<=3) {
sheet.setColumnWidth(i, 1600);
}else if(excelName[i].length()==4) {
boolean status = excelName[i].contains("日期");
if(status) {
sheet.setColumnWidth(i, 5200);
}else{
sheet.setColumnWidth(i, 3000);
}
}
if(excelName[i].length()>=6) {
sheet.setColumnWidth(i, 4000);
}
}
//
}
}