關於POI導出excel的功能我在前面的文章已經寫過了,POI導出excel的三種方式 , 導出表格數據到excel並下載(HSSFWorkbook版) ，本篇文章主要是將導入導出功能進一步地封裝，在項目中使用工具類直接調用即可。下面是工具類的代碼:
pom依賴:
<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>
工具類:
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相關處理 */ 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; } /** * 用於將科學計數法式的數字轉換為常規數字顯示,BigDecimal表示。<br> * 如：6.913084212242E12 轉換成：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) { // 有數據時才處理 得到類的所有field. Field[] allFields = clazz.getDeclaredFields(); // 定義一個map用於存放列的序號和field. List< Field> fieldsMap = new ArrayList<>(); for (int col = 0; col < allFields.length; col++) { Field field = allFields[col]; // 將有注解的field存放到map中. if (field.isAnnotationPresent(Excel.class)) { // 設置類的私有字段屬性可訪問. field.setAccessible(true); fieldsMap.add(field); } } for (int i = 1; i < rows; i++) { // 從第2行開始取數據,默認第一行是表頭. Row row = sheet.getRow(i); //獲取一行所有的單元格的數量 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); // 如果不存在實例則新建. entity = entity == null ? clazz.newInstance() : entity; // 從map中得到對應列的field. Field field = fieldsMap.get(j); // 取得類型,並根據對象類型設置值. 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; } /** * 導出excel到網絡（直接將http） * * @param list * @param sheetName * @param response * @return */ public void exportExcelToWeb(List<T> list, String sheetName, HttpServletResponse response) { // 告訴瀏覽器用什么軟件可以打開此文件 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 { // 告訴瀏覽器用什么軟件可以打開此文件 response.setContentType("application/octet-stream"); response.setCharacterEncoding("UTF-8"); SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd"); String fileName =df.format(new Date())+"導出數據"; 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(); } } /** * 導出excel到指定路徑 * * @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; } /** * 對list數據源將其里面的數據導入到excel表單 * * 通過制定out，實現導出到磁盤/網絡 * * @param sheetName 工作表的名稱 */ public ReturnResult exportExcel(List<T> list, String sheetName,OutputStream out) { // 得到所有定義字段 Field[] allFields = clazz.getDeclaredFields(); List<Field> fields = new ArrayList<Field>(); // 得到所有field並存放到一個list中. for (Field field : allFields) { if (field.isAnnotationPresent(Excel.class)) { fields.add(field); } } // 產生工作薄對象 HSSFWorkbook workbook = new HSSFWorkbook(); // excel2003中每個sheet中最多有65536行 int sheetSize = 65536; // 取出一共有多少個sheet. double sheetNo = Math.ceil(list.size() / sheetSize); for (int index = 0; index <= sheetNo; index++) { // 產生工作表對象 HSSFSheet sheet = workbook.createSheet(); if (sheetNo == 0) { workbook.setSheetName(index, sheetName); } else { // 設置工作表的名稱. workbook.setSheetName(index, sheetName + index); } HSSFRow row; HSSFCell cell; // 產生單元格 // 產生一行 row = sheet.createRow(0); // 寫入各個字段的列頭名稱 for (int i = 0; i < fields.size(); i++) { Field field = fields.get(i); Excel attr = field.getAnnotation(Excel.class); // 創建列 cell = row.createCell(i); // 設置列中寫入內容為String類型 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(); // 粗體顯示 font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD); // 選擇需要用到的字體格式 cellStyle.setFont(font); cellStyle.setFillForegroundColor(HSSFColor.LIGHT_YELLOW.index); // 設置列寬 sheet.setColumnWidth(i, 3766); } cellStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND); cellStyle.setWrapText(true); cell.setCellStyle(cellStyle); // 寫入列名 cell.setCellValue(attr.name()); // 如果設置了提示信息則鼠標放上去提示. if (!StringUtils.isEmpty(attr.prompt())) { // 這里默認設了2-101列提示. setHSSFPrompt(sheet, "", attr.prompt(), 1, 100, i, i); } // 如果設置了combo屬性則本列只能選擇不能輸入 if (attr.combo().length > 0) { // 這里默認設了2-101列只能選擇不能輸入. setHSSFValidation(sheet, attr.combo(), 1, 100, i, i); } } int startNo = index * sheetSize; int endNo = Math.min(startNo + sheetSize, list.size()); // 寫入各條記錄,每條記錄對應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); // 得到導出對象. T vo = (T) list.get(i); for (int j = 0; j < fields.size(); j++) { // 獲得field. Field field = fields.get(j); // 設置實體類私有屬性可訪問 field.setAccessible(true); Excel attr = field.getAnnotation(Excel.class); try { // 根據Excel中設置情況決定是否導出,有些情況需要保持為空,希望用戶填寫這一列. if (attr.isExport()) { // 創建cell cell = row.createCell(j); cell.setCellStyle(cs); try { if (String.valueOf(field.get(vo)).length() > 10) { throw new Exception("長度超過10位就不用轉數字了"); } // 如果可以轉成數字則導出為數字類型 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) { // 如果數據存在就填入,不存在填入空格. cell.setCellValue(""); } else { // 如果數據存在就填入,不存在填入空格. cell.setCellValue(field.get(vo) == null ? "" : String.valueOf(field.get(vo))); } } } } catch (Exception e) { log.error("導出Excel失敗{}", 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("關閉flush失敗{}", e.getMessage()); ReturnResult returnResult = new ReturnResult(); returnResult.setMsg("導出Excel失敗，請聯系網站管理員！"); returnResult.setCode(-1); return returnResult; } } /** * 設置單元格上提示 * * @param sheet 要設置的sheet. * @param promptTitle 標題 * @param promptContent 內容 * @param firstRow 開始行 * @param endRow 結束行 * @param firstCol 開始列 * @param endCol 結束列 * @return 設置好的sheet. */ public static HSSFSheet setHSSFPrompt(HSSFSheet sheet, String promptTitle, String promptContent, int firstRow, int endRow, int firstCol, int endCol) { // 構造constraint對象 DVConstraint constraint = DVConstraint.createCustomFormulaConstraint("DD1"); // 四個參數分別是：起始行、終止行、起始列、終止列 CellRangeAddressList regions = new CellRangeAddressList(firstRow, endRow, firstCol, endCol); // 數據有效性對象 HSSFDataValidation dataValidationView = new HSSFDataValidation(regions, constraint); dataValidationView.createPromptBox(promptTitle, promptContent); sheet.addValidationData(dataValidationView); return sheet; } /** * 設置某些列的值只能輸入預制的數據,顯示下拉框. * * @param sheet 要設置的sheet. * @param textlist 下拉框顯示的內容 * @param firstRow 開始行 * @param endRow 結束行 * @param firstCol 開始列 * @param endCol 結束列 * @return 設置好的sheet. */ public static HSSFSheet setHSSFValidation(HSSFSheet sheet, String[] textlist, int firstRow, int endRow, int firstCol, int endCol) { // 加載下拉列表內容 DVConstraint constraint = DVConstraint.createExplicitListConstraint(textlist); // 設置數據有效性加載在哪個單元格上,四個參數分別是：起始行、終止行、起始列、終止列 CellRangeAddressList regions = new CellRangeAddressList(firstRow, endRow, firstCol, endCol); // 數據有效性對象 HSSFDataValidation dataValidationList = new HSSFDataValidation(regions, constraint); sheet.addValidationData(dataValidationList); return sheet; } /** * 編碼文件名 */ 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; } }
注解類,用於導出時，列名稱的設置
package com.wang.demo.excel.annotation; import java.lang.annotation.*; /** * 自定義導出Excel數據注解 */ @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.FIELD) @Documented public @interface Excel { /** * 導出到Excel中的名字. */ public abstract String name(); /** * 提示信息 */ public abstract String prompt() default ""; /** * 設置只能選擇不能輸入的列內容. */ public abstract String[] combo() default {}; /** * 是否導出數據,應對需求:有時我們需要導出一份模板,這是標題需要但內容需要用戶手工填寫. */ public abstract boolean isExport() default true; }
返回類型，這個可以根據自己需要的自己定義
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); } }
導出功能
導出數據到excel只需要建一個實體類,使用工具類時，傳入實體類的作為泛型，然后給實體類的屬性加上@Excel(name="xxx")就可以導出響應的數據了，name是excel的列名稱。注意:如果不給屬性標上注解，該列就不會被導出到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,"用戶信息表",response);
}
實體類:
package com.wang.demo.excel.dto; import com.wang.demo.excel.annotation.Excel; public class UserDto { @Excel(name = "ID") private String id; @Excel(name = "用戶名") private String username; @Excel(name = "密碼") 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; } }
導入功能
導入功能的主要目的是獲取excel中的數據，使用工具類進行導入也十分方便。只需要接收到前端傳過來的file對象，然后使用file獲取到InputStream流即可獲取到該數據，並根據傳入的泛型自動解析成該類。注意:這邊的實體類的屬性名稱要和excel表的屬性名稱一致，否則會報錯。
前端部分
<form th:action="@{/user/import}" method="post" enctype="multipart/form-data">
<input name ="file" type="file">
<input type="submit" value="上傳">
</form>
服務器端
@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();
}
}