场景
要求每行数据的每个字段的内容不能以 [2,3,33,22] 形式展示 要求独立成列形式如下
代码
maven 依赖
<dependency><groupId>org.apache.poi</groupId><artifactId>poi</artifactId><version>3.17</version></dependency><dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml</artifactId><version>3.17</version></dependency><dependency><groupId>org.apache.poi</groupId><artifactId>poi-scratchpad</artifactId><version>3.17</version></dependency>
主代码类
package org.fri.controller;import lombok.extern.slf4j.Slf4j;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.FillPatternType;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.util.CellRangeAddress;
import org.fri.entity.ExportExample;
import org.fri.entity.MergeVo;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.*;@RequestMapping(value = "/excel")
@RestController
@Slf4j
public class ExcelController {@RequestMapping(value = "/export")public void exportExcel(HttpServletResponse response) throws NoSuchFieldException, IllegalAccessException, InstantiationException {ExportExample q = new ExportExample("漩涡鸣人", 20, "男", "火影,吊车尾,后宫之术创始人", "隐分身,仙术,螺旋丸");ExportExample y = new ExportExample("宇智波 佐助", 27, "男", "宇智波一族", "装B");ExportExample f = new ExportExample("千手扉间", 100, "男", "火影,禁术编写者", "水遁,黑暗术");LinkedHashMap<String, String> title = new LinkedHashMap<>();title.put("name","名称");title.put("age","年龄");title.put("sex","性别");title.put("roles","角色");title.put("technique","技能");List<ExportExample> list = Arrays.asList(q, y, f);exportExcel(list, ExportExample.class,title, response);}public <T> void exportExcel(List<T> list, Class<T> T,LinkedHashMap<String, String> title,HttpServletResponse response) throws NoSuchFieldException, IllegalAccessException, InstantiationException {T t = T.newInstance();LinkedHashMap<String, MergeVo> merged = new LinkedHashMap<>();Field[] fields = t.getClass().getDeclaredFields();//查询出所有列值for (Field field : fields) {field.setAccessible(true);merged.put(field.getName(), new MergeVo(field.getName(), 0, 1));}//计算所需要合并列的最大项for (T s : list) {for (String key : merged.keySet()) {Field field = t.getClass().getDeclaredField(key);field.setAccessible(true);String value = field.get(s).toString();if (merged.get(key).getTitleMaxColumNumber() < value.split(",").length) {merged.get(key).setTitleMaxColumNumber(value.split(",").length);}}}//计算没列的开始位置int j = 0;for (Map.Entry<String, MergeVo> et : merged.entrySet()) {et.getValue().setStartRowIndex(j);j = j + et.getValue().getTitleMaxColumNumber();}HSSFWorkbook workBook = null;OutputStream out = null;try {workBook = new HSSFWorkbook();HSSFSheet sheet = workBook.createSheet();HSSFRow titleRows = sheet.createRow(0);/*//设置表头样式CellStyle colorStyle = workBook.createCellStyle();colorStyle.setFillForegroundColor(IndexedColors.LIGHT_BLUE.getIndex());colorStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);Font font = workBook.createFont();font.setBold(true);font.setFontHeightInPoints((short) 16);// 设置字体大小为 16*/// 构建表头merged.forEach((key1, value) -> {merged(merged, sheet, titleRows, key1, title.get(key1));});// 构建数据int rowNumbers = 0;for (T e : list) {rowNumbers++;HSSFRow nextRow = sheet.createRow(rowNumbers);for (String key1 : merged.keySet()) {Field field = t.getClass().getDeclaredField(key1);field.setAccessible(true);String value = field.get(e).toString();merged(merged, sheet, nextRow, key1, value);}}DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMddHHmmss");String dateNow = formatter.format(LocalDateTime.now());String fileName = dateNow + ".xls";response.setCharacterEncoding("UTF-8");response.setContentType("application/x-msdownload");response.addHeader("Content-Disposition", "attachment;filename=" + fileName);out = response.getOutputStream();workBook.write(out);} catch (IOException e) {log.error(e.getMessage());} finally {try {if (out != null) {out.close();}if (workBook != null) {workBook.close();}} catch (IOException e) {log.error(e.getMessage());}}}/*** 合并规则设定** @param mergeVoMap 表头配置信息* @param sheet 所属sheet* @param row 所属行* @param key 所属key* @param value 值*/private void merged(LinkedHashMap<String, MergeVo> mergeVoMap, HSSFSheet sheet, HSSFRow row, Stringkey, String value) {MergeVo mergeVo = mergeVoMap.get(key);String[] split = value.replace("[", "").replace("]", "").split(",");if (mergeVo.getTitleMaxColumNumber() > 1) {if (split.length > 1) {int length = split.length;List<int[]> ints = splitIntoSegments(mergeVo.getStartRowIndex(), mergeVo.getStartRowIndex() + mergeVo.getTitleMaxColumNumber(), length);for (int j = 0; j < ints.size(); j++) {int[] anInt = ints.get(j);row.createCell(anInt[0]).setCellValue(split[j]);if (anInt[1] - anInt[0] > 0) {sheet.addMergedRegion(new CellRangeAddress(row.getRowNum(), row.getRowNum(), anInt[0], anInt[1]));}}} else {row.createCell(mergeVo.getStartRowIndex()).setCellValue(value);sheet.addMergedRegion(new CellRangeAddress(row.getRowNum(), row.getRowNum(), mergeVo.getStartRowIndex(), mergeVo.getStartRowIndex() + mergeVo.getTitleMaxColumNumber() - 1));}} else {row.createCell(mergeVo.getStartRowIndex()).setCellValue(value);}}/*** 列合并分割分配** @param s* @param e* @param x* @return*/public static List<int[]> splitIntoSegments(int s, int e, int x) {int i = e - s;List<int[]> segments = new ArrayList<>();int baseLength = i / x; // 每段的基本长度int remainder = i % x; // 剩余的数值int start = 0; // 起始值for (int k = 1; k <= x; k++) {int length = baseLength; // 当前段的长度if (k <= remainder) {length += 1; // 分配剩余的数值}int end = start + length - 1; // 结束值segments.add(new int[]{start + s, end + s}); // 添加到结果列表start = end + 1; // 更新下一段的起始值}return segments;}
}
合并项辅助类
package org.fri.entity;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@AllArgsConstructor
@NoArgsConstructor
public class MergeVo {private String key;private int startRowIndex;private int titleMaxColumNumber;
}
导出测试类
package org.fri.entity;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;/*** @author Lenovo*/
@Data
@AllArgsConstructor
@NoArgsConstructor
public class ExportExample {private String name;private Integer age;private String sex;private String roles;private String technique;
}