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SpringBoot之导入导出Excel(Java8实现)

SpringBoot之导入导出Excel(Java8实现)

作者: 丶兔小胖 | 来源:发表于2018-09-27 19:57 被阅读0次

    1.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>
    

    2.自定义实体类所需要的bean
    ExcelColumn

    @Target({ElementType.FIELD})
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    public @interface ExcelColumn {
    
        String value() default "";
    
        int col() default 0;
    }
    

    3.ExcelUtils编写

    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.*;
    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 javax.servlet.http.HttpServletResponse;
    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.*;
    import java.util.concurrent.atomic.AtomicInteger;
    import java.util.stream.Collectors;
    import java.util.stream.Stream;
    
    /**
     * @author Abbot
     * @description
     * @date 2018/9/12 15:27
     **/
    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("上传文件格式不正确");
            }
            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) {
                    //类映射  注解 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起到的作用和continue是相同的 语法
                                    }
                                    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);
                    //默认读取第一个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  提取注解
                        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();
                                //判断是否为空白行
                                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);
                //数字类型
            } 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 (DateUtil.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();
                //写入头部
                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());
                        }
                    });
                });
            }
            //冻结窗格
            wb.getSheet("Sheet1").createFreezePane(0, 1, 0, 1);
            //浏览器下载excel
            buildExcelDocument("abbot.xlsx",wb,response);
            //生成excel文件
    //        buildExcelFile(".\\default.xlsx",wb);
        }
    
        /**
         * 浏览器下载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路径
         * @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();
            }
        }
    }
    

    4.定义导出实体类

    /**
     * @author Abbot
     * @description
     * @date 2018/9/17 9:39
     **/
    public class BusClick {
    
        @ExcelColumn(value = "cityCode", col = 1)
        private String cityCode;
    
        @ExcelColumn(value = "markId", 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;
    
        //省略getter and setter 方法
    

    5.Controller层代码编写

    /**
     * @author Abbot
     * @description
     * @date 2018/9/17 11:24
     **/
    @RestController
    @RequestMapping("/excel")
    @Api(value = "excel导入导出", tags = "excel导入导出", description = "excel导入导出")
    public class ExcelController extends BaseController {
    
        @Autowired
        ExcelService excelService;
    
        @RequestMapping(value = "/exportExcel", method = RequestMethod.GET)
        public void exportExcel()  throws IOException {
            HttpServletResponse response = getHttpResponse();
    
            List<BusClick> resultList = excelService.getBusClick();
    
            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(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))
            );
        }
    }
    

    6.代码测试

    访问swagger2 Api接口文档
    (springBoot集成swagger2 参考之前一篇文章)

    (SpringBoot 集成Swagger2)

    注:导出需要从浏览器直接访问接口地址

    导出测试:

    1. 导出1000条数据
    write over! cost:736ms
    

    2. 导出10000条数据

    write over! cost:2273ms
    
    1. 导出100000条数据
    write over! cost:20087ms
    

    读取测试:

    1. 读取1000条数据
    read over! cost:131ms
    

    idea控制台打印如下

    1. 读取10000条数据
    read over! cost:818ms
    

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