springboot poi
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pom.xml
<dependency> <groupId>org.apache.poi</groupId> <artifactId>poi</artifactId> <version>3.9</version> </dependency> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-ooxml</artifactId> <version>3.9</version> </dependency> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-ooxml-schemas</artifactId> <version>3.9</version> </dependency>
ExcelUtil.java
package com.zjjw.cases.web; import com.alibaba.nacos.common.util.UuidUtils; import java.io.OutputStream; import java.lang.reflect.Field; import java.lang.reflect.Modifier; import java.math.BigDecimal; import java.net.URLEncoder; import java.util.Calendar; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.servlet.http.HttpServletResponse; import lombok.extern.slf4j.Slf4j; import org.apache.poi.hssf.usermodel.HSSFCellStyle; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.CellStyle; import org.apache.poi.ss.usermodel.Font; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.xssf.streaming.SXSSFSheet; import org.apache.poi.xssf.streaming.SXSSFWorkbook; import org.springframework.util.StringUtils; @Slf4j public class ExcelUtil { private static Integer MAXROWS = 1048000; public synchronized static <Ty> void outfile(HttpServletResponse response, Map<String, String> map, String sheetname, List<Ty> list) throws Exception { String uuid = UuidUtils.generateUuid(); log.info("id:{},执行导出开始",uuid); //创建poi导出数据对象 SXSSFWorkbook sxssfWorkbook = new SXSSFWorkbook(1000); //创建全局样式 CellStyle cellStyle = sxssfWorkbook.createCellStyle(); cellStyle.setFillForegroundColor((short) 10); cellStyle.setBorderBottom(CellStyle.BORDER_NONE); //下边框 cellStyle.setBorderLeft(CellStyle.BORDER_NONE);//左边框 cellStyle.setBorderTop(CellStyle.BORDER_NONE);//上边框 cellStyle.setBorderRight(CellStyle.BORDER_NONE);//右边框 cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);//水平居中 cellStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER); //垂直居中 //cellStyle.setWrapText(true);//自动换行 Font font = sxssfWorkbook.createFont(); font.setFontName("宋体");//设置字体 short pintSize = 10; font.setFontHeightInPoints(pintSize);//设置字体大小 // font.setBold(true);//加粗 cellStyle.setFont(font); int integer = list.size(); if (MAXROWS<integer) { throw new RuntimeException("数据行数超过excel最大数据行数!"); } if (integer > 0) { //数据量过大分批拉取 int k = 0; //一个sheet最大行数 final int pageNum = 500000; double count = deciMal(integer, pageNum); double num = Math.ceil(count); int j = 1; while (num != 0) { String newsheetname = sheetname + j; if (num == 1) { List<Ty> subList = list.subList(k, integer); setData(map, newsheetname, sxssfWorkbook, cellStyle, pintSize, subList); } else { List<Ty> subList = list.subList(k, k + pageNum); k = k + pageNum; // 创建sheet页 setData(map, newsheetname, sxssfWorkbook, cellStyle, pintSize, subList); } num--; j++; } } // 下载导出 String filename = sheetname + getNowTime(); //创建一个输出流 OutputStream outputStream = null; try { // 设置头信息 response.setCharacterEncoding("UTF-8"); response.setContentType("application/vnd.ms-excel"); //一定要设置成xlsx格式 response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename + ".xlsx", "UTF-8")); outputStream = response.getOutputStream(); //写入数据 sxssfWorkbook.write(outputStream); outputStream.flush(); } catch (Exception e) { e.printStackTrace(); } finally { if (null != outputStream) { outputStream.close(); } } log.info("id:{},执行导出结束",uuid); } private static double deciMal(int top, int below) { float f = (float)top/below; double result = new BigDecimal(f).setScale(6, BigDecimal.ROUND_HALF_UP).doubleValue(); return result; } private static <Ty> void setData(Map<String, String> map, String newsheetname, SXSSFWorkbook sxssfWorkbook, CellStyle cellStyle, short pintSize, List<Ty> subList) { // 创建sheet页 SXSSFSheet sheet = (SXSSFSheet) sxssfWorkbook.createSheet(newsheetname); int size = map.size() - 1; /** 合并表头 CellRangeAddress region = new CellRangeAddress(0, 0, (short) 0, (short) size); //参数1:起始行 参数2:终止行 参数3:起始列 参数4:终止列 sheet.addMergedRegion(region); SXSSFRow headTitle = sheet.createRow(0); SXSSFCell cellHeadTitle = headTitle.createCell(0); cellHeadTitle.setCellValue(newsheetname); cellHeadTitle.setCellStyle(cellStyle); //创建表头 SXSSFRow headRow = sheet.createRow(1);*/ Row headRow = sheet.createRow(0); //设置excel表头 int i = 0; for (Map.Entry<String, String> entry : map.entrySet()) { String mapKey = entry.getKey(); String[] split = mapKey.split("-"); mapKey = split[0]; //设置表头宽度 if (split.length > 1) { int titlewidth = Integer.parseInt(split[1]); titlewidth = titlewidth * pintSize * 30; sheet.setColumnWidth(i, titlewidth); } Cell cell = headRow.createCell(i); cell.setCellValue(mapKey); cell.setCellStyle(cellStyle); i++; } // 遍历上面数据库查到的数据 for (Ty t : subList) { Row dataRow = sheet.createRow(sheet.getLastRowNum() + 1); Map<String, Object> data = null; if (t instanceof Map) { data = (Map<String, Object>) t; } else { data = object2Map(t); } //设置excel表头 int j = 0; for (Map.Entry<String, String> entry : map.entrySet()) { String mapValue = entry.getValue(); Cell cell = dataRow.createCell(j); Object obj = data.get(mapValue); String value = ""; if (!StringUtils.isEmpty(obj)) { value = value + obj; } cell.setCellValue(value); cell.setCellStyle(cellStyle); j++; } } } private static String getNowTime() //获取当前系统时间并格式化 { System.setProperty("user.timezone", "GMT+08"); Calendar calendar = Calendar.getInstance(); int year = calendar.get(Calendar.YEAR); int month = calendar.get(Calendar.MONTH) + 1; int date = calendar.get(Calendar.DATE); int hour = calendar.get(Calendar.HOUR_OF_DAY); int minute = calendar.get(Calendar.MINUTE); int second = calendar.get(Calendar.SECOND); // String nowTime = year + "-" + month + "-" + date + "-" + hour + "-" + minute + "-" + second; String nowTime = year + "" + month + "" + date + "" + hour + "" + minute + "" + second; return nowTime; } /** * 实体对象转成Map * * @param obj 实体对象 * @return */ private static Map<String, Object> object2Map(Object obj) { Map<String, Object> map = new HashMap<String, Object>(); if (obj == null) { return map; } Class clazz = obj.getClass(); Field[] fields = clazz.getDeclaredFields(); try { for (Field field : fields) { field.setAccessible(true); map.put(field.getName(), field.get(obj)); } } catch (Exception e) { log.error("object2Map方法异常",e); } return map; } /** * Map转成实体对象 * * @param map map实体对象包含属性 * @param clazz 实体对象类型 * @return */ private static <T> T map2Object(Map<String, Object> map, Class<T> clazz) { if (map == null) { return null; } T obj = null; try { obj = clazz.newInstance(); Field[] fields = obj.getClass().getDeclaredFields(); for (Field field : fields) { int mod = field.getModifiers(); if (Modifier.isStatic(mod) || Modifier.isFinal(mod)) { continue; } field.setAccessible(true); String filedTypeName = field.getType().getName(); if (filedTypeName.equalsIgnoreCase("java.util.date")) { String datetimestamp = String.valueOf(map.get(field.getName())); if (datetimestamp.equalsIgnoreCase("null")) { field.set(obj, null); } else { field.set(obj, new Date(Long.parseLong(datetimestamp))); } } else { field.set(obj, map.get(field.getName())); } } } catch (Exception e) { log.error("map2Object方法异常",e); } return obj; } }
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