SpringBoot之導入導出Excel

一、添加springBoot支持

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.13</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.13</version>
</dependency>

 

二、自定義實體類所須要的bean(Excel屬性標題、位置等)

package com.xinyartech.erp.core.annotation; import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; /** * 自定義實體類所須要的bean(Excel屬性標題、位置等) * * @author Lynch * */ @Target({ElementType.FIELD}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface ExcelColumn { /** * Excel標題 * * @return * @author Lynch */ String value() default ""; /** * Excel從左往右排列位置 * * @return * @author Lynch */
    int col() default 0; }

 

三、ExcelUtils編寫

package com.xinyartech.erp.core.util; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.lang.reflect.Constructor; import java.lang.reflect.Field; import java.math.BigDecimal; import java.net.URLEncoder; import java.util.ArrayList; import java.util.Arrays; import java.util.Comparator; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.concurrent.atomic.AtomicInteger; import java.util.stream.Collectors; import java.util.stream.Stream; import javax.servlet.http.HttpServletResponse; import org.apache.commons.collections.CollectionUtils; import org.apache.commons.lang3.BooleanUtils; import org.apache.commons.lang3.CharUtils; import org.apache.commons.lang3.StringUtils; import org.apache.commons.lang3.math.NumberUtils; import org.apache.poi.hssf.usermodel.HSSFDateUtil; import org.apache.poi.hssf.usermodel.HSSFWorkbook; 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.IndexedColors; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.ss.usermodel.Workbook; import org.apache.poi.xssf.usermodel.XSSFWorkbook; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.http.MediaType; import org.springframework.web.multipart.MultipartFile; import com.xinyartech.erp.core.annotation.ExcelColumn; public class ExcelUtils { private final static Logger log = LoggerFactory.getLogger(ExcelUtils.class); private final static String EXCEL2003 = "xls"; private final static String EXCEL2007 = "xlsx"; public static <T> List<T> readExcel(String path, Class<T> cls,MultipartFile file){ String fileName = file.getOriginalFilename(); if (!fileName.matches("^.+\\.(?i)(xls)$") && !fileName.matches("^.+\\.(?i)(xlsx)$")) { log.error("上傳文件格式不正確"); } List<T> dataList = new ArrayList<>(); Workbook workbook = null; try { InputStream is = file.getInputStream(); if (fileName.endsWith(EXCEL2007)) { // FileInputStream is = new FileInputStream(new File(path));
                workbook = new XSSFWorkbook(is); } if (fileName.endsWith(EXCEL2003)) { // FileInputStream is = new FileInputStream(new File(path));
                workbook = new HSSFWorkbook(is); } if (workbook != null) { //類映射 註解 value-->bean columns
                Map<String, List<Field>> classMap = new HashMap<>(); List<Field> fields = Stream.of(cls.getDeclaredFields()).collect(Collectors.toList()); fields.forEach( field -> { ExcelColumn annotation = field.getAnnotation(ExcelColumn.class); if (annotation != null) { String value = annotation.value(); if (StringUtils.isBlank(value)) { return;//return起到的做用和continue是相同的 語法
 } if (!classMap.containsKey(value)) { classMap.put(value, new ArrayList<>()); } field.setAccessible(true); classMap.get(value).add(field); } } ); //索引-->columns
                Map<Integer, List<Field>> reflectionMap = new HashMap<>(16); //默認讀取第一個sheet
                Sheet sheet = workbook.getSheetAt(0); boolean firstRow = true; for (int i = sheet.getFirstRowNum(); i <= sheet.getLastRowNum(); i++) { Row row = sheet.getRow(i); //首行 提取註解
                    if (firstRow) { for (int j = row.getFirstCellNum(); j <= row.getLastCellNum(); j++) { Cell cell = row.getCell(j); String cellValue = getCellValue(cell); if (classMap.containsKey(cellValue)) { reflectionMap.put(j, classMap.get(cellValue)); } } firstRow = false; } else { //忽略空白行
                        if (row == null) { continue; } try { T t = cls.newInstance(); //判斷是否爲空白行
                            boolean allBlank = true; for (int j = row.getFirstCellNum(); j <= row.getLastCellNum(); j++) { if (reflectionMap.containsKey(j)) { Cell cell = row.getCell(j); String cellValue = getCellValue(cell); if (StringUtils.isNotBlank(cellValue)) { allBlank = false; } List<Field> fieldList = reflectionMap.get(j); fieldList.forEach( x -> { try { handleField(t, cellValue, x); } catch (Exception e) { log.error(String.format("reflect field:%s value:%s exception!", x.getName(), cellValue), e); } } ); } } if (!allBlank) { dataList.add(t); } else { log.warn(String.format("row:%s is blank ignore!", i)); } } catch (Exception e) { log.error(String.format("parse row:%s exception!", i), e); } } } } } catch (Exception e) { log.error(String.format("parse excel exception!"), e); } finally { if (workbook != null) { try { workbook.close(); } catch (Exception e) { log.error(String.format("parse excel exception!"), e); } } } return dataList; } private static <T> void handleField(T t, String value, Field field) throws Exception { Class<?> type = field.getType(); if (type == null || type == void.class || StringUtils.isBlank(value)) { return; } if (type == Object.class) { field.set(t, value); //數字類型
        } else if (type.getSuperclass() == null || type.getSuperclass() == Number.class) { if (type == int.class || type == Integer.class) { field.set(t, NumberUtils.toInt(value)); } else if (type == long.class || type == Long.class) { field.set(t, NumberUtils.toLong(value)); } else if (type == byte.class || type == Byte.class) { field.set(t, NumberUtils.toByte(value)); } else if (type == short.class || type == Short.class) { field.set(t, NumberUtils.toShort(value)); } else if (type == double.class || type == Double.class) { field.set(t, NumberUtils.toDouble(value)); } else if (type == float.class || type == Float.class) { field.set(t, NumberUtils.toFloat(value)); } else if (type == char.class || type == Character.class) { field.set(t, CharUtils.toChar(value)); } else if (type == boolean.class) { field.set(t, BooleanUtils.toBoolean(value)); } else if (type == BigDecimal.class) { field.set(t, new BigDecimal(value)); } } else if (type == Boolean.class) { field.set(t, BooleanUtils.toBoolean(value)); } else if (type == Date.class) { //  field.set(t, value); } else if (type == String.class) { field.set(t, value); } else { Constructor<?> constructor = type.getConstructor(String.class); field.set(t, constructor.newInstance(value)); } } private static String getCellValue(Cell cell) { if (cell == null) { return ""; } if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) { if (HSSFDateUtil.isCellDateFormatted(cell)) { return HSSFDateUtil.getJavaDate(cell.getNumericCellValue()).toString(); } else { return new BigDecimal(cell.getNumericCellValue()).toString(); } } else if (cell.getCellType() == Cell.CELL_TYPE_STRING) { return StringUtils.trimToEmpty(cell.getStringCellValue()); } else if (cell.getCellType() == Cell.CELL_TYPE_FORMULA) { return StringUtils.trimToEmpty(cell.getCellFormula()); } else if (cell.getCellType() == Cell.CELL_TYPE_BLANK) { return ""; } else if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN) { return String.valueOf(cell.getBooleanCellValue()); } else if (cell.getCellType() == Cell.CELL_TYPE_ERROR) { return "ERROR"; } else { return cell.toString().trim(); } } public static <T> void writeExcel(HttpServletResponse response, List<T> dataList, Class<T> cls){ Field[] fields = cls.getDeclaredFields(); List<Field> fieldList = Arrays.stream(fields) .filter(field -> { ExcelColumn annotation = field.getAnnotation(ExcelColumn.class); if (annotation != null && annotation.col() > 0) { field.setAccessible(true); return true; } return false; }).sorted(Comparator.comparing(field -> { int col = 0; ExcelColumn annotation = field.getAnnotation(ExcelColumn.class); if (annotation != null) { col = annotation.col(); } return col; })).collect(Collectors.toList()); Workbook wb = new XSSFWorkbook(); Sheet sheet = wb.createSheet("Sheet1"); AtomicInteger ai = new AtomicInteger(); { Row row = sheet.createRow(ai.getAndIncrement()); AtomicInteger aj = new AtomicInteger(); //寫入頭部
            fieldList.forEach(field -> { ExcelColumn annotation = field.getAnnotation(ExcelColumn.class); String columnName = ""; if (annotation != null) { columnName = annotation.value(); } Cell cell = row.createCell(aj.getAndIncrement()); CellStyle cellStyle = wb.createCellStyle(); cellStyle.setFillForegroundColor(IndexedColors.WHITE.getIndex()); cellStyle.setFillPattern(CellStyle.SOLID_FOREGROUND); cellStyle.setAlignment(CellStyle.ALIGN_CENTER); Font font = wb.createFont(); font.setBoldweight(Font.BOLDWEIGHT_NORMAL); cellStyle.setFont(font); cell.setCellStyle(cellStyle); cell.setCellValue(columnName); }); } if (CollectionUtils.isNotEmpty(dataList)) { dataList.forEach(t -> { Row row1 = sheet.createRow(ai.getAndIncrement()); AtomicInteger aj = new AtomicInteger(); fieldList.forEach(field -> { Class<?> type = field.getType(); Object value = ""; try { value = field.get(t); } catch (Exception e) { e.printStackTrace(); } Cell cell = row1.createCell(aj.getAndIncrement()); if (value != null) { if (type == Date.class) { cell.setCellValue(value.toString()); } else { cell.setCellValue(value.toString()); } cell.setCellValue(value.toString()); } }); }); } //凍結窗格
        wb.getSheet("Sheet1").createFreezePane(0, 1, 0, 1); //瀏覽器下載excel
        buildExcelDocument("abbot.xlsx",wb,response); //生成excel文件 // buildExcelFile(".\\default.xlsx",wb);
 } /** * 瀏覽器下載excel * @param fileName * @param wb * @param response */

    private static  void buildExcelDocument(String fileName, Workbook wb,HttpServletResponse response){ try { response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE); response.setHeader("Content-Disposition", "attachment;filename="+URLEncoder.encode(fileName, "utf-8")); response.flushBuffer(); wb.write(response.getOutputStream()); } catch (IOException e) { e.printStackTrace(); } } /** * 生成excel文件 * @param path 生成excel路徑 * @param wb */
    private static  void buildExcelFile(String path, Workbook wb){ File file = new File(path); if (file.exists()) { file.delete(); } try { wb.write(new FileOutputStream(file)); } catch (Exception e) { e.printStackTrace(); } } }

 

四、定義導出實體類

package com.xinyartech.erp.system.dto; import com.xinyartech.erp.core.annotation.ExcelColumn; import lombok.Data; /** * * * @author Lynch */ @Data public class BusClick { @ExcelColumn(value = "地區編碼", col = 1) private String cityCode; @ExcelColumn(value = "標誌", col = 2) private String markId; @ExcelColumn(value = "toaluv", col = 3) private String toaluv; @ExcelColumn(value = "date", col = 4) private String date; @ExcelColumn(value = "clientVer", col = 5) private String clientVer; @Override public String toString() { return "BusClick [cityCode=" + cityCode + ", markId=" + markId + ", toaluv=" + toaluv + ", date=" + date + ", clientVer=" + clientVer + "]"; } }

 

五、Controller層代碼編寫

package com.xinyartech.erp.system.web; import java.io.IOException; import java.util.ArrayList; import java.util.List; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.multipart.MultipartFile; import com.alibaba.fastjson.JSON; import com.xinyartech.erp.core.base.BaseUserController; import com.xinyartech.erp.core.util.ExcelUtils; import com.xinyartech.erp.system.dto.BusClick; import com.xinyartech.erp.system.model.SysUser; import com.xinyartech.erp.system.service.UserService; @Controller @RequestMapping("/api/hello") public class HelloWorldController extends BaseUserController<UserService, SysUser> { private static final Logger log = LogManager.getLogger(HelloWorldController.class); @RequestMapping(value = "/exportExcel", method = RequestMethod.GET) public void exportExcel()  throws IOException { List<BusClick> resultList = new ArrayList<BusClick>(); BusClick busClick = new BusClick(); busClick.setCityCode("a1"); busClick.setClientVer("a2"); busClick.setDate("a3"); busClick.setMarkId("a4"); busClick.setToaluv("a5"); resultList.add(busClick); busClick = new BusClick(); busClick.setCityCode("b1"); busClick.setClientVer("b2"); busClick.setDate("b3"); busClick.setMarkId("b4"); busClick.setToaluv("b5"); resultList.add(busClick); long t1 = System.currentTimeMillis(); ExcelUtils.writeExcel(response, resultList, BusClick.class); long t2 = System.currentTimeMillis(); System.out.println(String.format("write over! cost:%sms", (t2 - t1))); } @RequestMapping(value = "/readExcel", method = RequestMethod.POST) public void readExcel(@RequestParam(value="uploadFile", required = false) MultipartFile file){ long t1 = System.currentTimeMillis(); List<BusClick> list = ExcelUtils.readExcel("", BusClick.class, file); long t2 = System.currentTimeMillis(); System.out.println(String.format("read over! cost:%sms", (t2 - t1))); list.forEach( b -> System.out.println(JSON.toJSONString(b)) ); } } 

 

 

六、導出訪問地址
http://localhost:8091/api/hello/exportExcel

七、導入訪問地址
http://localhost:8091/api/hello/readExcel

控制檯打印的Excel信息：
read over! cost:69ms
{"cityCode":"a1","clientVer":"a2","date":"a3","markId":"a4","toaluv":"a5"}
{"cityCode":"b1","clientVer":"b2","date":"b3","markId":"b4","toaluv":"b5"}