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Java把数据导出Excel表格

Java把数据导出Excel表格

作者: 樱花舞 | 来源:发表于2018-12-30 13:56 被阅读0次

    1、需要引入的依赖包

    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi</artifactId>
        <version>3.15</version>
    </dependency>
    

    2、代码实现

    package com.my.projects.utils.office;
    
    import com.alibaba.fastjson.JSON;
    import com.my.projects.utils.constant.ErrorCode;
    import com.my.projects.utils.use.Response;
    import org.apache.commons.lang.StringUtils;
    import org.apache.commons.lang.time.DateFormatUtils;
    import org.apache.poi.hssf.usermodel.HSSFCell;
    import org.apache.poi.hssf.usermodel.HSSFRow;
    import org.apache.poi.hssf.usermodel.HSSFSheet;
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.http.MediaType;
    import org.springframework.util.CollectionUtils;
    
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.lang.reflect.Field;
    import java.util.List;
    
    /**
     * @author: fengchangxin
     * @created: 2018/9/3 21:28
     * @decription:生成Excel表格
     */
    public class ExcelUtil {
        private static final Logger LOGGER = LoggerFactory.getLogger(ExcelUtil.class);
    
    
        /**
         * @param sheetName 表格名
         * @param fileName  文件名
         * @param headers   表格第一行头名称
         * @param content   表格内容
         * @param c         内容对应的class
         * @return
         */
        public static void createExcel(String sheetName, String fileName, List<String> headers,
                                       List<?> content, Class<?> c, HttpServletResponse response) {
            OutputStream outputStream = null;
            try {
                response.setHeader("Content-type", MediaType.APPLICATION_JSON_UTF8_VALUE);
                response.setCharacterEncoding("UTF-8");
                HSSFWorkbook wb = new HSSFWorkbook();
                HSSFSheet sheet = wb.createSheet(sheetName);
                HSSFRow row = sheet.createRow(0);
                if (!CollectionUtils.isEmpty(headers)) {
                    HSSFCell cell;
                    for (int i = 0; i < headers.size(); i++) {
                        cell = row.createCell((short) i);
                        cell.setCellValue(headers.get(i));
                    }
                }
                if (CollectionUtils.isEmpty(content)) {
                    response.getWriter().println(JSON.toJSONString(Response.newFail(ErrorCode.ERROR_101.getCode(), ErrorCode.ERROR_101.getMsg())));
                    return;
                }
                if (StringUtils.isBlank(fileName)) {
                    fileName = DateFormatUtils.format(System.currentTimeMillis(), "yyyyMMddHHmmss");
                }
    
                //获取class属性
                Field[] fields = c.getDeclaredFields();
                int contentSize = content.size();
                int fieldsLength = fields.length;
                for (int j = 0; j < contentSize; j++) {
                    Object o = content.get(j);
                    //创建行
                    row = sheet.createRow(j + 1);
                    for (int m = 0; m < fieldsLength; m++) {
                        Field field = fields[m];
                        field.setAccessible(true);
                        try {
                            //创建单元格
                            row.createCell((short) m).setCellValue(String.valueOf(field.get(o)));
                        } catch (Exception e) {
                            LOGGER.error("{}", e.getMessage());
                            response.getWriter().println(JSON.toJSONString(Response.newFail(ErrorCode.ERROR_102.getCode(), ErrorCode.ERROR_102.getMsg())));
                            return;
                        }
                    }
                }
    
                response.setHeader("Content-disposition", new String("attachment; filename=".concat(fileName).concat(".xls").getBytes("gbk"), "ISO-8859-1"));
                outputStream = response.getOutputStream();
                wb.write(outputStream);
            } catch (IOException e) {
                LOGGER.error("{}", e.getMessage());
                return;
            } finally {
                try {
                    if (outputStream != null) {
                        outputStream.close();
                    }
                } catch (IOException ee) {
                    LOGGER.error("fail to close IO,{}", ee.getMessage());
                }
    
            }
        }
    }
    

    2.1 对第一种方法修改

    /**
         * @param sheetName 表格名
         * @param fileName  文件名
         * @param headers   表格第一行头名称
         * @param content   表格内容
         * @return
         */
        public static void createExcel(String sheetName, String fileName, String[] headers,
                                       String[][] content, HttpServletResponse response) {
            OutputStream outputStream = null;
            try {
                response.setHeader("Content-type", MediaType.APPLICATION_JSON_UTF8_VALUE);
                response.setCharacterEncoding("UTF-8");
                HSSFWorkbook wb = new HSSFWorkbook();
                HSSFSheet sheet = wb.createSheet(sheetName);
                HSSFRow row = sheet.createRow(0);
                //生成表格导航栏
                if (!ArrayUtils.isEmpty(headers)) {
                    HSSFCell cell;
                    for (int i = 0; i < headers.length; i++) {
                        cell = row.createCell(i);
                        cell.setCellValue(headers[i]);
                    }
                }
                if (ArrayUtils.isEmpty(content)) {
                    return;
                }
                if (StringUtils.isBlank(fileName)) {
                    fileName = DateFormatUtils.format(System.currentTimeMillis(), "yyyyMMddHHmmss");
                }
    
                int valueLength = content.length;
                for (int i = 0; i < valueLength; i++) {
                    //创建行
                    row = sheet.createRow(i + 1);
                    int length = content[i].length;
                    for (int j = 0; j < length; j++) {
                        //创建单元格
                        row.createCell((short) j).setCellValue(content[i][j]);
                    }
                }
    
                response.setContentType("application/octet-stream");
                response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.
                        concat(".xls").getBytes("UTF-8"), "ISO-8859-1"));
                outputStream = response.getOutputStream();
                wb.write(outputStream);
            } catch (IOException e) {
                LOGGER.error("{}", e.getMessage());
                return;
            } finally {
                try {
                    if (outputStream != null) {
                        outputStream.close();
                    }
                } catch (IOException ee) {
                    LOGGER.error("fail to close IO,{}", ee.getMessage());
                }
    
            }
        }
    

    注意:接口返回要用void类型。

    2.2使用阿里巴巴的easyExcel

    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>easyexcel</artifactId>
        <version>2.1.4</version>
    </dependency>
    

    简单例子:

    @Data
    @ContentRowHeight(10)
    @HeadRowHeight(20)
    @ColumnWidth(25)
    public class DataDTO {
        @ExcelProperty(value = "名称", index = 0)
        private String name;
        @ExcelProperty(value = "年龄", index = 2)
        @ColumnWidth(50)
        private Integer age;
        @ExcelProperty(value = "时间", index = 1)
        private Date time;
    }
    
    public class ExcelUtils {
        public static void main(String[] args) {
            String fileName = "E://test.xlsx";
            EasyExcel.write(fileName, DataDTO.class).sheet("模板").doWrite(getData());
        }
    
        private static List<DataDTO> getData() {
            List<DataDTO> list = new ArrayList<>();
            for (int i = 0; i < 100; i++) {
                DataDTO dataDTO = new DataDTO();
                dataDTO.setAge(i);
                dataDTO.setName("name" + i);
                dataDTO.setTime(new Date());
                list.add(dataDTO);
            }
            return list;
        }
    }
    

    easyExcel对poi做了很多的优化,更简单使用,更推荐这种方式,不用像前面写那么复杂,对Date和图片格式都支持,更多功能去官网了解,有详细的demo,不过不支持LocalDateTime时间类型,因为easyExcel是基于jdk1.7的。在对应的dto使用注解就可读取字段信息。官方文档:https://github.com/alibaba/easyexcel

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