POI导入导出excel(附工具类)
关于POI导出excel的功能我在前面的文章已经写过了,POI导出excel的三种方式 , 导出表格数据到excel并下载(HSSFWorkbook版) ，本篇文章主要是将导入导出功能进一步地封装，在项目中使用工具类直接调用即可。下面是工具类的代码:
pom依赖:
<dependency> <groupId>org.apache.poi</groupId> <artifactId>poi</artifactId> <version>3.5-beta6</version> </dependency> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-ooxml</artifactId> <version>3.5-beta6</version> </dependency> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-scratchpad</artifactId> <version>3.5-beta6</version> </dependency> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-contrib</artifactId> <version>3.5-beta6</version> </dependency>
工具类:
package com.wang.demo.excel.util; import com.wang.demo.excel.annotation.Excel; import com.wang.demo.excel.dto.ReturnResult; import org.apache.poi.hssf.usermodel.*; import org.apache.poi.hssf.util.HSSFColor; import org.apache.poi.ss.usermodel.*; import org.apache.poi.ss.util.CellRangeAddressList; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.util.StringUtils; import javax.servlet.http.HttpServletResponse; import java.io.*; import java.lang.reflect.Field; import java.math.BigDecimal; import java.net.URLEncoder; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.UUID; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * Excel相关处理 */ 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; } /** * 用于将科学计数法式的数字转换为常规数字显示,BigDecimal表示。<br> * 如：6.913084212242E12 转换成：6940282300075 * @param obj as Object * @return */ public static String decimal2string(Object obj){ BigDecimal big = null; if(obj==null) return ""; if(obj instanceof Number){ big = new BigDecimal(((Number)obj).doubleValue()); }else{ return obj.toString(); } return big==null ? "" : big.toPlainString(); } 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.isEmpty(sheetName)){ sheet = workbook.getSheetAt(0); }else{ sheet = workbook.getSheet(sheetName); } int rows = sheet.getPhysicalNumberOfRows(); if (rows > 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. List< Field> fieldsMap = new ArrayList<>(); 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.add(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); //获取一行所有的单元格的数量 int cellNum = sheet.getRow(0).getPhysicalNumberOfCells(); T entity = null; for (int j = 0; j < cellNum; j++) { Cell cell = row.getCell(j); if (cell == null) { continue; } else { cell = row.getCell(j); } String c = null; if(cell.getCellType()==Cell.CELL_TYPE_NUMERIC) { c = decimal2string(cell.getNumericCellValue()); }else c = cell.getStringCellValue(); if (StringUtils.isEmpty(c)) { continue; } c= replaceBlank(c); // 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); // 取得类型,并根据对象类型设置值. Class<?> fieldType = field.getType(); // Class<?> fieldType = String.class; 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 (Date.class == fieldType) { if (cell.getCellType() == Cell.CELL_TYPE_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 (BigDecimal.class == fieldType) { c = cell.getStringCellValue(); } } if (entity != null) { list.add(entity); } } } return list; } /** * 导出excel到网络（直接将http） * * @param list * @param sheetName * @param response * @return */ public void exportExcelToWeb(List<T> list, String sheetName, HttpServletResponse response) { // 告诉浏览器用什么软件可以打开此文件 response.setContentType("multipart/form-data"); response.setCharacterEncoding("utf-8"); try { response.setHeader("Content-Disposition", "attachment;filename="+ URLEncoder.encode(sheetName + ".xls", "utf-8")); this.exportExcel(list,sheetName,response.getOutputStream()); } catch (Exception e) { e.printStackTrace(); } } public void download(List<T> list, String sheetName, HttpServletResponse response) throws UnsupportedEncodingException { // 告诉浏览器用什么软件可以打开此文件 response.setContentType("application/octet-stream"); response.setCharacterEncoding("UTF-8"); SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd"); String fileName =df.format(new Date())+"导出数据"; fileName = URLEncoder.encode(fileName, "UTF-8"); try { response.addHeader("Content-Disposition", "attachment;filename=" +fileName + ".xls"); this.exportExcel(list,sheetName,response.getOutputStream()); } catch (Exception e) { e.printStackTrace(); } } /** * 导出excel到指定路径 * * @param list * @param sheetName * @param path * @return */ public ReturnResult exportExcelToPath(List<T> list, String sheetName,String path) { ReturnResult returnResult = null; try { OutputStream out = new FileOutputStream(path); returnResult = this.exportExcel(list,sheetName,out); } catch (Exception e) { e.printStackTrace(); } return returnResult; } /** * 对list数据源将其里面的数据导入到excel表单 * * 通过制定out，实现导出到磁盘/网络 * * @param sheetName 工作表的名称 */ public ReturnResult exportExcel(List<T> list, String sheetName,OutputStream out) { // 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 HSSFWorkbook 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(HSSFCell.CELL_TYPE_STRING); HSSFCellStyle cellStyle = workbook.createCellStyle(); cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER); cellStyle.setVerticalAlignment(CellStyle.VERTICAL_CENTER); if (attr.name().indexOf("注：") >= 0) { HSSFFont font = workbook.createFont(); font.setColor(HSSFFont.COLOR_RED); cellStyle.setFont(font); cellStyle.setFillForegroundColor(HSSFColor.LIGHT_YELLOW.index); sheet.setColumnWidth(i, 6000); } else { HSSFFont font = workbook.createFont(); // 粗体显示 font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD); // 选择需要用到的字体格式 cellStyle.setFont(font); cellStyle.setFillForegroundColor(HSSFColor.LIGHT_YELLOW.index); // 设置列宽 sheet.setColumnWidth(i, 3766); } cellStyle.setFillPattern(HSSFCellStyle.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.isEmpty(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(HSSFCellStyle.ALIGN_CENTER); cs.setVerticalAlignment(CellStyle.VERTICAL_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 { // 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); try { if (String.valueOf(field.get(vo)).length() > 10) { throw new Exception("长度超过10位就不用转数字了"); } // 如果可以转成数字则导出为数字类型 BigDecimal bc = new BigDecimal(String.valueOf(field.get(vo))); cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC); cell.setCellValue(bc.doubleValue()); } catch (Exception e) { cell.setCellType(HSSFCell.CELL_TYPE_STRING); if (vo == null) { // 如果数据存在就填入,不存在填入空格. cell.setCellValue(""); } else { // 如果数据存在就填入,不存在填入空格. cell.setCellValue(field.get(vo) == null ? "" : String.valueOf(field.get(vo))); } } } } catch (Exception e) { log.error("导出Excel失败{}", e.getMessage()); } } } } try { String filename = encodingFilename(sheetName); //OutputStream out = new FileOutputStream(getfile() + filename); workbook.write(out); out.close(); ReturnResult returnResult = new ReturnResult(); returnResult.setMsg("filename"); returnResult.setCode(1); return returnResult; } catch (Exception e) { log.error("关闭flush失败{}", e.getMessage()); ReturnResult returnResult = new ReturnResult(); returnResult.setMsg("导出Excel失败，请联系网站管理员！"); returnResult.setCode(-1); return returnResult; } } /** * 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; } /** * 编码文件名 */ public String encodingFilename(String filename) { filename = UUID.randomUUID().toString() + "_" + filename + ".xls"; return filename; } public String replaceBlank(String str) { String dest = ""; if (str!=null) { Pattern p = Pattern.compile("\\s*|\t|\r|\n"); Matcher m = p.matcher(str); dest = m.replaceAll(""); } return dest; } }
注解类,用于导出时，列名称的设置
package com.wang.demo.excel.annotation; import java.lang.annotation.*; /** * 自定义导出Excel数据注解 */ @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.FIELD) @Documented public @interface Excel { /** * 导出到Excel中的名字. */ public abstract String name(); /** * 提示信息 */ public abstract String prompt() default ""; /** * 设置只能选择不能输入的列内容. */ public abstract 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 abstract boolean isExport() default true; }
返回类型，这个可以根据自己需要的自己定义
package com.wang.demo.excel.dto; import java.io.Serializable; import java.util.HashMap; import java.util.Map; public class ReturnResult implements Serializable { private static final long serialVersionUID = 6816265515135254415L; public ReturnResult(){ } public ReturnResult(int c, String m){ this.code = c; this.msg = m; } public ReturnResult(int c, String m, Map<String, Object> dataMap){ this(c, m); this.data = dataMap; } private Map<String, Object> data; protected int code = 0; protected String msg = ""; public int getCode() { return code; } public void setCode(int code) { this.code = code; } public String getMsg() { return msg; } public void setMsg(String msg) { this.msg = msg; } public Map<String, Object> getData() { return data; } public void setData(Map<String, Object> data) { this.data = data; } public void putAll(Map<String, Object> data){ if(this.data == null) this.data = new HashMap<String, Object>(); this.data.putAll(data); } public void put(String key, Object value){ if(this.data == null) this.data = new HashMap<String, Object>(); this.data.put(key, value); } }
导出功能
导出数据到excel只需要建一个实体类,使用工具类时，传入实体类的作为泛型，然后给实体类的属性加上@Excel(name="xxx")就可以导出响应的数据了，name是excel的列名称。注意:如果不给属性标上注解，该列就不会被导出到excel。
@RequestMapping("/user/export")
public void exportExcel(HttpServletResponse response){
ExcelUtil<UserDto> excelUtil = new ExcelUtil<>(UserDto.class);
List<UserDto> userDtos = new ArrayList<>();
UserDto userDto1 = new UserDto();
userDto1.setId("aa");
userDto1.setPassword("wang");
userDto1.setUsername("xia");
userDtos.add(userDto1);
excelUtil.exportExcelToWeb(userDtos,"用户信息表",response);
}
实体类:
package com.wang.demo.excel.dto; import com.wang.demo.excel.annotation.Excel; public class UserDto { @Excel(name = "ID") private String id; @Excel(name = "用户名") private String username; @Excel(name = "密码") private String password; @Override public String toString() { return "UserDto{" + "id='" + id + '\'' + ", username='" + username + '\'' + ", password='" + password + '\'' + '}'; } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
导入功能
导入功能的主要目的是获取excel中的数据，使用工具类进行导入也十分方便。只需要接收到前端传过来的file对象，然后使用file获取到InputStream流即可获取到该数据，并根据传入的泛型自动解析成该类。注意:这边的实体类的属性名称要和excel表的属性名称一致，否则会报错。
前端部分
<form th:action="@{/user/import}" method="post" enctype="multipart/form-data">
<input name ="file" type="file">
<input type="submit" value="上传">
</form>
服务器端
@RequestMapping("/user/import")
public void importExcel(@RequestParam("file") MultipartFile file){
try {
InputStream inputStream = file.getInputStream();
ExcelUtil<UserDto> excelUtil = new ExcelUtil<>(UserDto.class);
List<UserDto> userDtos = excelUtil.importExcel(null, inputStream);
System.out.println(userDtos.size());
} catch (Exception e) {
e.printStackTrace();
}
}
