Java之基于注解的Excel导出
原文地址：https://blog.csdn.net/wenxingchen/article/details/84791205
数据库Excel导出操作代码过于冗长惨不忍睹,无法复用。
目录
注解配合工具类做了个小工具如下:
第一步：自定义注解:
package com.ruoyi.framework.aspectj.lang.annotation; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; /** * 自定义导出Excel数据注解 * * @author ruoyi */ @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.FIELD) public @interface Excel { /** * 导出到Excel中的名字. */ public String name(); /** * 日期格式, 如: yyyy-MM-dd */ public String dateFormat() default ""; /** * 读取内容转表达式 (如: 0=男,1=女,2=未知) */ public String readConverterExp() default ""; /** * 导出时在excel中每个列的高度 单位为字符 */ public double height() default 14; /** * 导出时在excel中每个列的宽 单位为字符 */ public double width() default 20; /** * 文字后缀,如% 90 变成90% */ public String suffix() default ""; /** * 当值为空时,字段的默认值 */ public String defaultValue() default ""; /** * 提示信息 */ public String prompt() default ""; /** * 设置只能选择不能输入的列内容. */ public String[] combo() default {}; /** * 是否导出数据,应对需求:有时我们需要导出一份模板,这是标题需要但内容需要用户手工填写. */ public boolean isExport() default true; }
第二步：实体类:
package com.ruoyi.project.system.dict.domain; import org.apache.commons.lang3.builder.ToStringBuilder; import org.apache.commons.lang3.builder.ToStringStyle; import com.ruoyi.framework.aspectj.lang.annotation.Excel; import com.ruoyi.framework.web.domain.BaseEntity; /** * 字典数据表 sys_dict_data * * @author ruoyi */ public class DictData extends BaseEntity { private static final long serialVersionUID = 1L; /** 字典编码 */ @Excel(name = "字典编码") private Long dictCode; /** 字典排序 */ @Excel(name = "字典排序") private Long dictSort; /** 字典标签 */ @Excel(name = "字典标签") private String dictLabel; /** 字典键值 */ @Excel(name = "字典键值") private String dictValue; /** 字典类型 */ @Excel(name = "字典类型") private String dictType; /** 字典样式 */ @Excel(name = "字典样式") private String cssClass; /** 表格字典样式 */ private String listClass; /** 是否默认（Y是 N否） */ @Excel(name = "是否默认", readConverterExp = "Y=是,N=否") private String isDefault; /** 状态（0正常 1停用） */ @Excel(name = "状态", readConverterExp = "0=正常,1=停用") private String status; public Long getDictCode() { return dictCode; } public void setDictCode(Long dictCode) { this.dictCode = dictCode; } public Long getDictSort() { return dictSort; } public void setDictSort(Long dictSort) { this.dictSort = dictSort; } public String getDictLabel() { return dictLabel; } public void setDictLabel(String dictLabel) { this.dictLabel = dictLabel; } public String getDictValue() { return dictValue; } public void setDictValue(String dictValue) { this.dictValue = dictValue; } public String getDictType() { return dictType; } public void setDictType(String dictType) { this.dictType = dictType; } public String getCssClass() { return cssClass; } public void setCssClass(String cssClass) { this.cssClass = cssClass; } public String getListClass() { return listClass; } public void setListClass(String listClass) { this.listClass = listClass; } public String getIsDefault() { return isDefault; } public void setIsDefault(String isDefault) { this.isDefault = isDefault; } public String getStatus() { return status; } public void setStatus(String status) { this.status = status; } @Override public String toString() { return new ToStringBuilder(this,ToStringStyle.MULTI_LINE_STYLE) .append("dictCode", getDictCode()) .append("dictSort", getDictSort()) .append("dictLabel", getDictLabel()) .append("dictValue", getDictValue()) .append("dictType", getDictType()) .append("cssClass", getCssClass()) .append("listClass", getListClass()) .append("isDefault", getIsDefault()) .append("status", getStatus()) .append("createBy", getCreateBy()) .append("createTime", getCreateTime()) .append("updateBy", getUpdateBy()) .append("updateTime", getUpdateTime()) .append("remark", getRemark()) .toString(); } }
第三步：解析工具类:
package com.ruoyi.common.utils.poi; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.lang.reflect.Field; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.UUID; import org.apache.poi.hssf.usermodel.DVConstraint; import org.apache.poi.hssf.usermodel.HSSFCell; import org.apache.poi.hssf.usermodel.HSSFCellStyle; import org.apache.poi.hssf.usermodel.HSSFDataValidation; import org.apache.poi.hssf.usermodel.HSSFFont; 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.hssf.util.HSSFColor.HSSFColorPredefined; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.CellType; import org.apache.poi.ss.usermodel.FillPatternType; import org.apache.poi.ss.usermodel.HorizontalAlignment; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.ss.usermodel.VerticalAlignment; import org.apache.poi.ss.usermodel.Workbook; import org.apache.poi.ss.usermodel.WorkbookFactory; import org.apache.poi.ss.util.CellRangeAddressList; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.ruoyi.common.utils.DateUtils; import com.ruoyi.common.utils.StringUtils; import com.ruoyi.framework.aspectj.lang.annotation.Excel; import com.ruoyi.framework.config.RuoYiConfig; import com.ruoyi.framework.web.domain.AjaxResult; /** * Excel相关处理 * * @author ruoyi */ public class ExcelUtil<T> { private static final Logger log = LoggerFactory.getLogger(ExcelUtil.class); public Class<T> clazz; public ExcelUtil(Class<T> clazz) { this.clazz = clazz; } /** * 对excel表单默认第一个索引名转换成list * * @param input 输入流 * @return 转换后集合 */ public List<T> importExcel(InputStream input) throws Exception { return importExcel(StringUtils.EMPTY, input); } /** * 对excel表单指定表格索引名转换成list * * @param sheetName 表格索引名 * @param input 输入流 * @return 转换后集合 */ public List<T> importExcel(String sheetName, InputStream input) throws Exception { List<T> list = new ArrayList<T>(); Workbook workbook = WorkbookFactory.create(input); Sheet sheet = null; if (StringUtils.isNotEmpty(sheetName)) { // 如果指定sheet名,则取指定sheet中的内容. sheet = workbook.getSheet(sheetName); } else { // 如果传入的sheet名不存在则默认指向第1个sheet. sheet = workbook.getSheetAt(0); } if (sheet == null) { throw new IOException("文件sheet不存在"); } int rows = sheet.getPhysicalNumberOfRows(); if (rows > 0) { // 默认序号 int serialNum = 0; // 有数据时才处理 得到类的所有field. Field[] allFields = clazz.getDeclaredFields(); // 定义一个map用于存放列的序号和field. Map<Integer, Field> fieldsMap = new HashMap<Integer, Field>(); for (int col = 0; col < allFields.length; col++) { Field field = allFields[col]; // 将有注解的field存放到map中. if (field.isAnnotationPresent(Excel.class)) { // 设置类的私有字段属性可访问. field.setAccessible(true); fieldsMap.put(++serialNum, field); } } for (int i = 1; i < rows; i++) { // 从第2行开始取数据,默认第一行是表头. Row row = sheet.getRow(i); int cellNum = serialNum; T entity = null; for (int j = 0; j < cellNum; j++) { Cell cell = row.getCell(j); if (cell == null) { continue; } else { // 先设置Cell的类型，然后就可以把纯数字作为String类型读进来了 row.getCell(j).setCellType(CellType.STRING); cell = row.getCell(j); } String c = cell.getStringCellValue(); if (StringUtils.isEmpty(c)) { continue; } // 如果不存在实例则新建. entity = (entity == null ? clazz.newInstance() : entity); // 从map中得到对应列的field. Field field = fieldsMap.get(j + 1); // 取得类型,并根据对象类型设置值. Class<?> fieldType = field.getType(); if (String.class == fieldType) { field.set(entity, String.valueOf(c)); } else if ((Integer.TYPE == fieldType) || (Integer.class == fieldType)) { field.set(entity, Integer.parseInt(c)); } else if ((Long.TYPE == fieldType) || (Long.class == fieldType)) { field.set(entity, Long.valueOf(c)); } else if ((Float.TYPE == fieldType) || (Float.class == fieldType)) { field.set(entity, Float.valueOf(c)); } else if ((Short.TYPE == fieldType) || (Short.class == fieldType)) { field.set(entity, Short.valueOf(c)); } else if ((Double.TYPE == fieldType) || (Double.class == fieldType)) { field.set(entity, Double.valueOf(c)); } else if (Character.TYPE == fieldType) { if ((c != null) && (c.length() > 0)) { field.set(entity, Character.valueOf(c.charAt(0))); } } else if (java.util.Date.class == fieldType) { if (cell.getCellTypeEnum() == CellType.NUMERIC) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); cell.setCellValue(sdf.format(cell.getNumericCellValue())); c = sdf.format(cell.getNumericCellValue()); } else { c = cell.getStringCellValue(); } } else if (java.math.BigDecimal.class == fieldType) { c = cell.getStringCellValue(); } } if (entity != null) { list.add(entity); } } } return list; } /** * 对list数据源将其里面的数据导入到excel表单 * * @param list 导出数据集合 * @param sheetName 工作表的名称 * @return 结果 */ public AjaxResult exportExcel(List<T> list, String sheetName) { OutputStream out = null; HSSFWorkbook workbook = null; try { // 得到所有定义字段 Field[] allFields = clazz.getDeclaredFields(); List<Field> fields = new ArrayList<Field>(); // 得到所有field并存放到一个list中. for (Field field : allFields) { if (field.isAnnotationPresent(Excel.class)) { fields.add(field); } } // 产生工作薄对象 workbook = new HSSFWorkbook(); // excel2003中每个sheet中最多有65536行 int sheetSize = 65536; // 取出一共有多少个sheet. double sheetNo = Math.ceil(list.size() / sheetSize); for (int index = 0; index <= sheetNo; index++) { // 产生工作表对象 HSSFSheet sheet = workbook.createSheet(); if (sheetNo == 0) { workbook.setSheetName(index, sheetName); } else { // 设置工作表的名称. workbook.setSheetName(index, sheetName + index); } HSSFRow row; HSSFCell cell; // 产生单元格 // 产生一行 row = sheet.createRow(0); // 写入各个字段的列头名称 for (int i = 0; i < fields.size(); i++) { Field field = fields.get(i); Excel attr = field.getAnnotation(Excel.class); // 创建列 cell = row.createCell(i); // 设置列中写入内容为String类型 cell.setCellType(CellType.STRING); HSSFCellStyle cellStyle = workbook.createCellStyle(); cellStyle.setAlignment(HorizontalAlignment.CENTER); cellStyle.setVerticalAlignment(VerticalAlignment.CENTER); if (attr.name().indexOf("注：") >= 0) { HSSFFont font = workbook.createFont(); font.setColor(HSSFFont.COLOR_RED); cellStyle.setFont(font); cellStyle.setFillForegroundColor(HSSFColorPredefined.YELLOW.getIndex()); sheet.setColumnWidth(i, 6000); } else { HSSFFont font = workbook.createFont(); // 粗体显示 font.setBold(true); // 选择需要用到的字体格式 cellStyle.setFont(font); cellStyle.setFillForegroundColor(HSSFColorPredefined.LIGHT_YELLOW.getIndex()); // 设置列宽 sheet.setColumnWidth(i, (int) ((attr.width() + 0.72) * 256)); row.setHeight((short) (attr.height() * 20)); } cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND); cellStyle.setWrapText(true); cell.setCellStyle(cellStyle); // 写入列名 cell.setCellValue(attr.name()); // 如果设置了提示信息则鼠标放上去提示. if (StringUtils.isNotEmpty(attr.prompt())) { // 这里默认设了2-101列提示. setHSSFPrompt(sheet, "", attr.prompt(), 1, 100, i, i); } // 如果设置了combo属性则本列只能选择不能输入 if (attr.combo().length > 0) { // 这里默认设了2-101列只能选择不能输入. setHSSFValidation(sheet, attr.combo(), 1, 100, i, i); } } int startNo = index * sheetSize; int endNo = Math.min(startNo + sheetSize, list.size()); // 写入各条记录,每条记录对应excel表中的一行 HSSFCellStyle cs = workbook.createCellStyle(); cs.setAlignment(HorizontalAlignment.CENTER); cs.setVerticalAlignment(VerticalAlignment.CENTER); for (int i = startNo; i < endNo; i++) { row = sheet.createRow(i + 1 - startNo); // 得到导出对象. T vo = (T) list.get(i); for (int j = 0; j < fields.size(); j++) { // 获得field. Field field = fields.get(j); // 设置实体类私有属性可访问 field.setAccessible(true); Excel attr = field.getAnnotation(Excel.class); try { // 设置行高 row.setHeight((short) (attr.height() * 20)); // 根据Excel中设置情况决定是否导出,有些情况需要保持为空,希望用户填写这一列. if (attr.isExport()) { // 创建cell cell = row.createCell(j); cell.setCellStyle(cs); if (vo == null) { // 如果数据存在就填入,不存在填入空格. cell.setCellValue(""); continue; } String dateFormat = attr.dateFormat(); String readConverterExp = attr.readConverterExp(); if (StringUtils.isNotEmpty(dateFormat)) { cell.setCellValue(DateUtils.parseDateToStr(dateFormat, (Date) field.get(vo))); } else if (StringUtils.isNotEmpty(readConverterExp)) { cell.setCellValue(convertByExp(String.valueOf(field.get(vo)), readConverterExp)); } else { cell.setCellType(CellType.STRING); // 如果数据存在就填入,不存在填入空格. cell.setCellValue(StringUtils.isNull(field.get(vo)) ? attr.defaultValue() : field.get(vo) + attr.suffix()); } } } catch (Exception e) { log.error("导出Excel失败{}", e.getMessage()); } } } } String filename = encodingFilename(sheetName); out = new FileOutputStream(getAbsoluteFile(filename)); workbook.write(out); return AjaxResult.success(filename); } catch (Exception e) { log.error("导出Excel异常{}", e.getMessage()); return AjaxResult.error("导出Excel失败，请联系网站管理员！"); } finally { if (workbook != null) { try { workbook.close(); } catch (IOException e1) { e1.printStackTrace(); } } if (out != null) { try { out.close(); } catch (IOException e1) { e1.printStackTrace(); } } } } /** * 设置单元格上提示 * * @param sheet 要设置的sheet. * @param promptTitle 标题 * @param promptContent 内容 * @param firstRow 开始行 * @param endRow 结束行 * @param firstCol 开始列 * @param endCol 结束列 * @return 设置好的sheet. */ public static HSSFSheet setHSSFPrompt(HSSFSheet sheet, String promptTitle, String promptContent, int firstRow, int endRow, int firstCol, int endCol) { // 构造constraint对象 DVConstraint constraint = DVConstraint.createCustomFormulaConstraint("DD1"); // 四个参数分别是：起始行、终止行、起始列、终止列 CellRangeAddressList regions = new CellRangeAddressList(firstRow, endRow, firstCol, endCol); // 数据有效性对象 HSSFDataValidation dataValidationView = new HSSFDataValidation(regions, constraint); dataValidationView.createPromptBox(promptTitle, promptContent); sheet.addValidationData(dataValidationView); return sheet; } /** * 设置某些列的值只能输入预制的数据,显示下拉框. * * @param sheet 要设置的sheet. * @param textlist 下拉框显示的内容 * @param firstRow 开始行 * @param endRow 结束行 * @param firstCol 开始列 * @param endCol 结束列 * @return 设置好的sheet. */ public static HSSFSheet setHSSFValidation(HSSFSheet sheet, String[] textlist, int firstRow, int endRow, int firstCol, int endCol) { // 加载下拉列表内容 DVConstraint constraint = DVConstraint.createExplicitListConstraint(textlist); // 设置数据有效性加载在哪个单元格上,四个参数分别是：起始行、终止行、起始列、终止列 CellRangeAddressList regions = new CellRangeAddressList(firstRow, endRow, firstCol, endCol); // 数据有效性对象 HSSFDataValidation dataValidationList = new HSSFDataValidation(regions, constraint); sheet.addValidationData(dataValidationList); return sheet; } /** * 解析导出值 0=男,1=女,2=未知 * * @param propertyValue 参数值 * @param converterExp 翻译注解 * @return 解析后值 * @throws Exception */ public static String convertByExp(String propertyValue, String converterExp) throws Exception { try { String[] convertSource = converterExp.split(","); for (String item : convertSource) { String[] itemArray = item.split("="); if (itemArray[0].equals(propertyValue)) { return itemArray[1]; } } } catch (Exception e) { throw e; } return propertyValue; } /** * 编码文件名 */ public String encodingFilename(String filename) { filename = UUID.randomUUID().toString() + "_" + filename + ".xls"; return filename; } /** * 获取下载路径 * * @param filename 文件名称 */ public String getAbsoluteFile(String filename) { String downloadPath = RuoYiConfig.getDownloadPath() + filename; File desc = new File(downloadPath); if (!desc.getParentFile().exists()) { desc.getParentFile().mkdirs(); } return downloadPath; } }
第四步：使用:
@Log(title = "字典数据", businessType = BusinessType.EXPORT) @RequiresPermissions("system:dict:export") @PostMapping("/export") @ResponseBody public AjaxResult export(DictData dictData) { List<DictData> list = dictDataService.selectDictDataList(dictData); ExcelUtil<DictData> util = new ExcelUtil<DictData>(DictData.class); return util.exportExcel(list, "dictData"); }
