1、引入maven依赖
<dependency><groupId>org.apache.poi</groupId><artifactId>poi</artifactId><version>4.1.0</version></dependency>
2、此处我们以合并多行数据为例,效果如下:
3、首先创建一个工作簿
HSSFWorkbook wb = new HSSFWorkbook();HSSFFont blackFont = getExportFont(wb);HSSFCellStyle cellStyle = wb.createCellStyle();private HSSFFont getExportFont(HSSFWorkbook wb) {HSSFFont blackFont = wb.createFont();blackFont.setColor(HSSFColor.HSSFColorPredefined.BLACK.getIndex());blackFont.setFontName("微软雅黑"); // 设置字体颜色blackFont.setFontHeightInPoints((short) 12);return blackFont;}
添加样式:
一、设置背景色:
cellStyle.setFillForegroundColor((short) 13);// 设置背景色
cellStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
二、设置边框:
cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN); //下边框
cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);//左边框
cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);//上边框
cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);//右边框
三、设置居中:
cellStyle.setAlignment(HorizontalAlignment.CENTER); //水平居中
cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
四、设置字体:
HSSFFont font = wb.createFont();
font.setFontName("黑体");
font.setFontHeightInPoints((short) 16);//设置字体大小
HSSFFont font2 = wb.createFont();
font2.setFontName("仿宋_GB2312");
font2.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);//粗体显示
font2.setFontHeightInPoints((short) 12);
cellStyle.setFont(font);//选择需要用到的字体格式
五、设置列宽:
sheet.setColumnWidth(0, 3766);
//第一个参数代表列id(从0开始),第2个参数代表宽度值 参考 :"-08-10"的宽度为2500
六、设置自动换行:
cellStyle.setWrapText(true);//设置自动换行
4、在创建一个空的Sheet页,如果要创建多个分页,遍历添加即可
int rowNum = 0; HSSFSheet sheet = wb.createSheet("Sheet1的标题");HSSFRow row = sheet.createRow(rowNum++);row.setHeight(new Short("1024")); // 设置第一行标题的行高Map<String,Integer> fieldIndexMap = new HashMap<>();// 遍历绑定标题int cellNum = 0;// titleMap里存的是标题集合{"ID":"ID","作者":"author","邮箱":"email","地址":"address","毕业院校":"education_school","出版书籍":"book","出版社":"publish","出版时间":"publish_time"}for (String key : titleMap.ketSet()) {sheet.setColumnWidth(cellNum, 6000); // 设置列宽,可以根据不同的内容自定义宽度cell = getCellWithValue(cell, cellNum, fieldList[i], blackFont, cellStyle, row);fieldIndexMap.put(titleMap.get(key), cellNum); // 存放标题名称和列号的对应关系,为了后面内容绑定的时候使用cellNum++;}// 将列的值绑定到列对象上private HSSFCell getCellWithValue(HSSFCell cell, int cellNum, String value, HSSFFont font, HSSFCellStyle cellStyle, HSSFRow row) {cell = row.createCell(cellNum);HSSFRichTextString hssfRichTextString = new HSSFRichTextString(value);hssfRichTextString.applyFont(0, value.length(), font);cell.setCellValue(hssfRichTextString);cell.setCellStyle(cellStyle);return cell;}
到此处,标题行已经生成好了,接下来生成内容行。
首先:假定我们的数据是JSON数组格式的,内容如下:
[{
"ID": "1",
"author": "张三",
"email": "1888888@",
"address": "北京中关村",
"education_school": "北京大学",
"book_info": [
{
"book": "Java入门到精通",
"publish": "人民出版社",
"publish_time": "/5/18"
},{
"book": "Mysql底层原理",
"publish": "人民出版社",
"publish_time": "/5/19"
},
........
]
},
........
]
根据上面的JSON数组数据进行遍历,其中book_info里面存的是出版书籍、出版社和出版时间字段,这里就是一个人会对应多条数据情况,那么就需要将书籍属于同一个人的个人信息行进行单元格合并,也就是行合并。
这里使用CellRangeAddress对象:
CellRangeAddress cellRangeAddress= new CellRangeAddress(firstRow ,lastRow ,firstColumn ,lastColumn);
参数分别为:起始行号,终止行号, 起始列号,终止列号
List<JSONObject> sourceMapList = JSONArray.parseArray(dataJson); // dataJson为上面的JSON数组数据for (JSONObject jsonObject: sourceMapList) {// 获取当前作者有多少本书,如果大于1本,则需要合并单元格List<JSONObject > bookInfoList= JSONArray.parseArray(String.valueOf(jsonObject.get("book_info")));if(bookInfoList.size() > 1){// 这里的rowNum 在上面创建完标题行后变为1,因为本例中需要将表格前五列的行按照书本的数量进行(行的合并)// 假如一个作者有三本书,在遍历完这个作者所有书的时候,rowNum将变成当前的rowNum + 3sheet.addMergedRegion(new CellRangeAddress(rowNum, rowNum + bookInfoList.size() -1, 0,0));sheet.addMergedRegion(new CellRangeAddress(rowNum, rowNum + bookInfoList.size() -1, 1,1));sheet.addMergedRegion(new CellRangeAddress(rowNum, rowNum + bookInfoList.size() -1, 2,2));sheet.addMergedRegion(new CellRangeAddress(rowNum, rowNum + bookInfoList.size() -1, 3,3));sheet.addMergedRegion(new CellRangeAddress(rowNum, rowNum + bookInfoList.size() -1, 4,4));}row = sheet.createRow(rowNum);// 接下来根据各个列的值绑定到cell对象就行了for (String key : personMap.keySet()) {if("book_info".equals(key)){// 书籍信息的行没有合并,这里需要在遍历的时候,将rowNum设置根据书籍数量自增HSSFRow sheetRow = null;for (int i = 0; i < bookInfoList.size(); i++) {sheetRow = sheet.createRow(rowNum);JSONObject jsonBook = bookInfoList.get(i);for (String feedKey: jsonBook.keySet()) {cell = getCellWithValue(cell, fieldIndexMap.get(feedKey), String.valueOf(jsonBook.get(feedKey)), blackFont, cellStyle, sheetRow);}rowNum++;}}else {cell = getCellWithValue(cell, fieldIndexMap.get(feedKey), String.valueOf(jsonBook.get(feedKey)), blackFont, cellStyle, sheetRow);}}
最后一步:导出
/*** wb 工作簿* filename 导出的文件名*/export(response, request, wb, response.getOutputStream(), filename);public static void export(HttpServletResponse resp, HttpServletRequest request, HSSFWorkbook work, OutputStream bos, String filename) throws IOException {String header = request.getHeader("User-Agent");if (header.contains("Firefox")) {BASE64Encoder base = new BASE64Encoder();filename = "=?utf-8?B?" + base.encode(filename.getBytes(StandardCharsets.UTF_8)) + "?=";} else {filename = URLEncoder.encode(filename, "UTF-8").replaceAll("\\+", "%20");}resp.setContentType("application/vnd.ms-excel");resp.addHeader("Content-Disposition", "attachment;fileName=" + filename);work.write(bos);work.close();bos.flush();bos.close();}