使用poi导出excel

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

        <!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.poi/poi-scratchpad -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-scratchpad</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml-schemas -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml-schemas</artifactId>
        </dependency>

package com.shiwen.yitihui.achievement.util;

import java.util.HashMap;
import java.util.Map;

/**
 * @author wangjie
 * @date 2019/12/21 11:41
 * @description 资料处理导出excel文件的模板
 * @company 石文软件有限公司
 */
public class Constants {

    public interface Redis {
        String DRILL_STATISTICS_PREFIX = "DRILL-DAILY:";
    }

    // 模板所在位置
    public static final String TEMP_LOCATION = "excel/";

    public static final String EXCEL_SUFFIX = ".xlsx";

    // excel模板下载映射名称
    public static final Map<String, String>  excelMap = new HashMap<>();

    static {
        excelMap.put("consolidated", "综合记录列表");
    }

    // 录井详情表头
   // public static final String DETAIL_HEADER = "井生产日报";
}

package com.shiwen.yitihui.achievement.util;

/**
 * @author wangjie
 * @date 2019/12/21 12:01
 * @description
 * @company 石文软件有限公司
 */
public class Enums {

    public enum DataReportType {
        CONSOLIDATED("consolidated"),
        SINGLE("single");

        private String value;

        DataReportType(String value) {
            this.value = value;
        }

        /**
         * 根据值获取类型
         *
         * @param value
         * @return
         */
        public static DataReportType getType(String value) {
            for (DataReportType type : DataReportType.values()) {
                if (type.getValue().equals(value)) {
                    return type;
                }
            }
            return null;
        }

        public String getValue() {
            return value;
        }
    }
}

package com.shiwen.yitihui.achievement.util;

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

/**
 * @author wangjie
 * @date 2019/12/20 18:26
 * @description
 * @company 石文软件有限公司
 */
public class ExcelUtils {

    /**
     * 创建Excel文件
     *
     * @param path 路径
     * @param list 数据
     * @param <T>  模板
     * @return
     * @throws IOException
     */
    public static <T> boolean writeExcel(Path path, List<T> list) throws IOException {
        boolean success = false;
        if (Files.notExists(path)) {
            throw new IllegalArgumentException("文件不存在！");
        } else {
            Workbook workbook = new XSSFWorkbook(new FileInputStream(path.toFile()));
            // 获取第一个sheet
            Sheet sheet = workbook.getSheetAt(0);
            // 遍历行
            Row row;
            Cell cell;
            int index = 1;
            Field[] fields = new Field[0];
            if (list != null && list.size() > 0) {
                // 利用反射获取传入对象第一个元素的所有属性
                fields = list.get(0).getClass().getDeclaredFields();
            }
            for (T value : list) {
                row = sheet.createRow(index++);
                // 遍历列
                for (int i = 0; i < fields.length; i++) {
                    // 创建单元格样式
                    cell = row.createCell(i);
                    // 水平居中，四边设置边框
                    CellStyle cellStyle = InitDataStyle.getHorizontalCenterBorder(workbook);
                    cellStyle.setWrapText(false); // 不换行
                    cell.setCellStyle(cellStyle);
                    // 获取当前行内容对象
                    try {
                        String filed = fields[i].getName();
                        // 反射方法过去值(都设置成String)
                        String val = getObjectValue(value, filed);
                        // 将值写入单元格
                        cell.setCellValue(val);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    // 设置列宽自动调整
                    sheet.autoSizeColumn(i);
                }
            }
            OutputStream os = null;
            try {
                os = new FileOutputStream(path.toFile());
                workbook.write(os);
                success = true;
            } finally {
                if (os != null) {
                    os.close();
                }
                if (workbook != null) {
                    workbook.close();
                }
            }
            return success;
        }


    }


    /**
     * 反射获取值
     *
     * @param obj       对象
     * @param cellValue 字段属性
     * @param <T>       泛型
     * @return String
     * @throws Exception
     */
    private static <T> String getObjectValue(T obj, String cellValue) throws Exception {
        String getName = "get" + cellValue.substring(0, 1).toUpperCase() + cellValue.substring(1);
        Method method = obj.getClass().getMethod(getName);
        return method.invoke(obj) != null ? String.valueOf(method.invoke(obj)) : "";
    }

    /**
     * 样式
     */
    public static class InitDataStyle {
        // 基础样式
        static CellStyle getNormal(Workbook wb) {
            CellStyle cellStyle = wb.createCellStyle();
            Font font = wb.createFont();
            font.setFontName("宋体");
            font.setFontHeightInPoints((short) 11);
            cellStyle.setFont(font);
            return cellStyle;
        }

        // 水平居中 四周边框
        static CellStyle getHorizontalCenterBorder(Workbook wb) {
            CellStyle cellStyle = getNormal(wb);
            cellStyle.setAlignment(HorizontalAlignment.CENTER);
            cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
            // 边框
            cellStyle.setBorderBottom(BorderStyle.THIN);
            cellStyle.setBorderLeft(BorderStyle.THIN);
            cellStyle.setBorderTop(BorderStyle.THIN);
            cellStyle.setBorderRight(BorderStyle.THIN);
            return cellStyle;
        }

    }

}

package com.shiwen.yitihui.achievement.util;

import java.io.InputStream;

/**
 * @Author Cwang
 * @Date 2019/7/12
 **/
public class FileUtil {

    public static InputStream getResourcesFileInputStream(String fileName) {
        return Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName);
    }
}

package com.shiwen.yitihui.achievement.service;

import java.io.IOException;
import java.nio.file.Path;

/**
 * @author wangjie
 * @date 2019/12/21 11:45
 * @description
 * @company 石文软件有限公司
 */
public interface DataReportExcelService {

    /**
     * 获取excel的二进制文件
     * @param type
     * @param
     * @return
     * @throws IOException
     */
    Path getExcelFile(String type, String jh) throws IOException;
}

package com.shiwen.yitihui.achievement.service.impl;

import com.shiwen.yitihui.achievement.dao.basic.ConsolidatedRecordsDao;
import com.shiwen.yitihui.achievement.service.DataReportExcelService;
import com.shiwen.yitihui.achievement.util.Constants;
import com.shiwen.yitihui.achievement.util.Enums;
import com.shiwen.yitihui.achievement.util.ExcelUtils;
import com.shiwen.yitihui.achievement.util.FileUtil;
import com.shiwen.yitihui.domain.basic.ConsolidatedRecords;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.util.List;
import java.util.UUID;

/**
 * @author wangjie
 * @date 2019/12/21 11:50
 * @description
 * @company 石文软件有限公司
 */
@Service
public class DataReportExcelServiceImpl implements DataReportExcelService {

    private static final String TEMP_FLODAE = System.getProperty("user.dir") + File.separator + "temp_excel";

    @Autowired
    private  ConsolidatedRecordsDao  consolidatedRecordsDao;

    @Override
    public Path getExcelFile(String type, String jh) throws IOException {
        Enums.DataReportType reportType = Enums.DataReportType.getType(type);
        if (reportType == null) {
            return null;
        }
        Path path = null;
        switch (reportType) {
            case CONSOLIDATED:
                List<ConsolidatedRecords> list = consolidatedRecordsDao.getListByJh(jh);
                path = handleExcel(type, list);
                break;
            default:
                break;
        }
        return path;
    }

    /**
     * 处理excel
     *
     * @param type
     * @param list
     * @param <T>
     * @throws IOException
     */
    private <T> Path handleExcel(String type, List<T> list) throws IOException {
        //读取对应excel文件的模板
        InputStream excel = FileUtil.getResourcesFileInputStream(Constants.TEMP_LOCATION + type + Constants.EXCEL_SUFFIX);
        //创建带有文件路径的path对象
        Path desPath = Paths.get(TEMP_FLODAE + File.separator + UUID.randomUUID().toString() + Constants.EXCEL_SUFFIX);
        Path pPath = desPath.getParent();

        if (Files.notExists(pPath)) {
            Files.createDirectory(pPath);
        }
        //将excel文件模板,拷贝到path对象中
        Files.copy(excel, desPath, StandardCopyOption.REPLACE_EXISTING);
        //
        if (Enums.DataReportType.SINGLE.getValue().equals(type)) {
            /*LoggingDTO logging = new LoggingDTO();
            if (list.size() > 0) {
                logging = (LoggingDTO) list.get(0);
            }
            ExcelUtils.writeExcelDetail(desPath, logging, Constants.DETAIL_HEADER);*/
            System.out.println("=================================使用定制模板");
        } else {
            ExcelUtils.writeExcel(desPath, list);
        }
        return desPath;
    }
}