技术汇总:第一章:使用poi实现表单下载成xls文件并打印
业务需求:
点击下载
第一种方式:
实现代码
@RequestMapping("/ad/downExcel")
public String downExcel(HttpSession session, HttpServletResponse response) {
try {
List<Ad> adlist = adService.getAdList();
String fileName="广告管理表";
List<Map<String,Object>> list=createExcelRecord(adlist);
String columnNames[]={"标题","链接","权重"};//列名
String keys[] = {"title","link","weight"};//map中的key
ByteArrayOutputStream os = new ByteArrayOutputStream();
try {
ExcelUtil.createWorkBook(list,keys,columnNames).write(os);
} catch (IOException e) {
e.printStackTrace();
}
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.ms-excel;charset=utf-8");
response.setHeader("Content-Disposition",
"attachment;filename="+ new String((fileName + ".xls").getBytes(),
"iso-8859-1"));
ServletOutputStream out = response.getOutputStream();
BufferedInputStream bis = null;
BufferedOutputStream bos = null;
try {
bis = new BufferedInputStream(is);
bos = new BufferedOutputStream(out);
byte[] buff = new byte[2048];
int bytesRead;
// Simple read/write loop.
while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
bos.write(buff, 0, bytesRead);
}
} catch (final IOException e) {
throw e;
} finally {
if (bis != null)
bis.close();
if (bos != null)
bos.close();
}
}catch (Exception e){
}
return null;
}
private List<Map<String, Object>> createExcelRecord(List<Ad> adList) {
List<Map<String, Object>> listmap = new ArrayList<Map<String, Object>>();
Map<String, Object> map = new HashMap<String, Object>();
map.put("sheetName", "sheet1");
listmap.add(map);
Map<String, Object> mapValue = null;
for (int j = 0; j < adList.size(); j++) {
Ad ad=adList.get(j);
mapValue = new HashMap<String, Object>();
mapValue.put("title", ad.getTitle());
mapValue.put("link",ad.getLink());
mapValue.put("weight",ad.getWeight());
listmap.add(mapValue);
}
return listmap;
}
工具类
package org.imooc.util;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import java.util.List;
import java.util.Map;
public class ExcelUtil {
/**
* 创建excel文档,
* list 数据
* @param keys list中map的key数组集合
* @param columnNames excel的列名
* */
public static Workbook createWorkBook(List<Map<String, Object>> list, String []keys, String columnNames[]) {
// 创建excel工作簿
Workbook wb = new HSSFWorkbook();
// 创建第一个sheet(页),并命名
Sheet sheet = wb.createSheet(list.get(0).get("sheetName").toString());
// 手动设置列宽。第一个参数表示要为第几列设;,第二个参数表示列的宽度,n为列高的像素数。
for(int i=0;i<keys.length;i++){
sheet.setColumnWidth((short) i, (short) (35.7 * 200));
}
// 创建第一行
Row row = sheet.createRow((short) 0);
// 创建两种单元格格式
CellStyle cs = wb.createCellStyle();
CellStyle cs2 = wb.createCellStyle();
// 创建两种字体
Font f = wb.createFont();
Font f2 = wb.createFont();
// 创建第一种字体样式(用于列名)
f.setFontHeightInPoints((short) 10);
f.setColor(IndexedColors.BLACK.getIndex());
f.setBoldweight(Font.BOLDWEIGHT_BOLD);
// 创建第二种字体样式(用于值)
f2.setFontHeightInPoints((short) 10);
f2.setColor(IndexedColors.BLACK.getIndex());
// Font f3=wb.createFont();
// f3.setFontHeightInPoints((short) 10);
// f3.setColor(IndexedColors.RED.getIndex());
// 设置第一种单元格的样式(用于列名)
cs.setFont(f);
cs.setBorderLeft(CellStyle.BORDER_THIN);
cs.setBorderRight(CellStyle.BORDER_THIN);
cs.setBorderTop(CellStyle.BORDER_THIN);
cs.setBorderBottom(CellStyle.BORDER_THIN);
cs.setAlignment(CellStyle.ALIGN_CENTER);
// 设置第二种单元格的样式(用于值)
cs2.setFont(f2);
cs2.setBorderLeft(CellStyle.BORDER_THIN);
cs2.setBorderRight(CellStyle.BORDER_THIN);
cs2.setBorderTop(CellStyle.BORDER_THIN);
cs2.setBorderBottom(CellStyle.BORDER_THIN);
cs2.setAlignment(CellStyle.ALIGN_CENTER);
//设置列名
for(int i=0;i<columnNames.length;i++){
Cell cell = row.createCell(i);
cell.setCellValue(columnNames[i]);
cell.setCellStyle(cs);
}
//设置每行每列的值
for (short i = 1; i < list.size(); i++) {
// Row 行,Cell 方格 , Row 和 Cell 都是从0开始计数的
// 创建一行,在页sheet上
Row row1 = sheet.createRow((short) i);
// 在row行上创建一个方格
for(short j=0;j<keys.length;j++){
Cell cell = row1.createCell(j);
cell.setCellValue(list.get(i).get(keys[j]) == null?" ": list.get(i).get(keys[j]).toString());
cell.setCellStyle(cs2);
}
}
return wb;
}
}
第二种方式:
先准备好一个空的名称为new的xls文件(名称和代码一致)
核心代码:
@RequestMapping("downExcel")
public void download() throws IOException{
List<Ad> adList = adService.getAdList();
String filePath = "D:\\new.xls";
File file = new File(filePath);
//事先要准备好一个名称为new的xls文件
InputStream is=new FileInputStream(file);
Workbook wb=new HSSFWorkbook(is);
Sheet sheet = wb.getSheetAt(0);
Row nRow=null;
Cell nCell=null;
//行号
int rowNo=0;
// 列号
int colNo=1;
//声明样式对象和字体对象
CellStyle nStyle=wb.createCellStyle();
Font font = wb.createFont();
sheet.setColumnWidth(0,2*300);
sheet.setColumnWidth(1,26*300);
sheet.setColumnWidth(2,12*300);
//大标题,合并单元格
sheet.addMergedRegion(new CellRangeAddress(0,0,1,3)); //开始行,结束行,开始列,结束列
// 合并单元格的内容写在合并前第一个单元格中
nRow=sheet.createRow(rowNo++);
nRow.setHeightInPoints(36);
nCell=nRow.createCell(1);
nCell.setCellValue("标题");
nCell.setCellStyle(this.bigTitle(wb, nStyle, font));
String[] title=new String[]{"id","标题","权重"};
nRow=sheet.createRow(rowNo++);
nRow.setHeightInPoints(26.25f);
//初始化
nStyle=wb.createCellStyle();
font=wb.createFont();
for(int i=0;i<title.length;i++){
nCell=nRow.createCell(i+1);
nCell.setCellValue(title[i]);
nCell.setCellStyle(this.Title(wb, nStyle, font));
}
//初始化
nStyle=wb.createCellStyle();
font=wb.createFont();
for (int i = 0; i < adList.size(); i++) {
Ad ad = adList.get(i);
colNo=1;
nRow=sheet.createRow(rowNo++);
nCell=nRow.createCell(colNo++);
nCell.setCellValue(ad.getId());
nCell.setCellStyle(this.Text(wb, nStyle, font));
nCell=nRow.createCell(colNo++);
nCell.setCellValue(ad.getTitle());
nCell.setCellStyle(this.Text(wb, nStyle, font));
nCell=nRow.createCell(colNo++);
nCell.setCellValue(ad.getWeight());
nCell.setCellStyle(this.Text(wb, nStyle, font));
}
OutputStream os=new FileOutputStream(file);
wb.write(os);
os.flush();
os.close();
}
各种样式代码
//大标题的样式
public CellStyle bigTitle(Workbook wb,CellStyle nStyle,Font font){
font.setFontName("宋体");
font.setFontHeightInPoints((short) 16);
//字体加粗
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
//横向居中
nStyle.setAlignment(CellStyle.ALIGN_CENTER);
//纵向居中
nStyle.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
//单元格垂直居中
nStyle.setFont(font); return nStyle;
}
//标题样式
public CellStyle Title(Workbook wb,CellStyle nStyle,Font font){
font.setFontName("黑体");
font.setFontHeightInPoints((short) 12);
//横向居中
nStyle.setAlignment(CellStyle.ALIGN_CENTER);
//纵向居中
nStyle.setVerticalAlignment(CellStyle.VERTICAL_CENTER);//单元格垂直居中
//表格线
nStyle.setBorderTop(CellStyle.BORDER_THICK);
//粗实线
nStyle.setBorderBottom(CellStyle.BORDER_THIN);
// 实线
nStyle.setBorderLeft(CellStyle.BORDER_THIN);
// 比较粗实线
nStyle.setBorderRight(CellStyle.BORDER_THIN);
// 实线
nStyle.setFont(font); return nStyle;
}
// 文字样式
public CellStyle Text(Workbook wb,CellStyle nStyle,Font font){
font.setFontName("Times New Roman");
font.setFontHeightInPoints((short) 10);
//横向居中
nStyle.setAlignment(CellStyle.ALIGN_CENTER);
//纵向居中
nStyle.setVerticalAlignment(CellStyle.VERTICAL_CENTER); //单元格垂直居中
// 表格线
nStyle.setBorderBottom(CellStyle.BORDER_THIN);
//实线
nStyle.setBorderLeft(CellStyle.BORDER_THIN);
// 比较粗实线
nStyle.setBorderRight(CellStyle.BORDER_THIN);
// 实线
nStyle.setFont(font); return nStyle;
}
完成下载去原来的new.xls文件查看