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    Java怎么导出Excel

    尚2019-12-03 09:44:27原创3138

    java实现Excel数据导出:(推荐:java视频教程

    目前,比较常用的实现Java导入、导出Excel的技术有两种Jakarta POI和Java Excel

    Jakarta POI 是一套用于访问微软格式文档的Java API。Jakarta POI有很多组件组成,其中有用于操作Excel格式文件的HSSF和用于操作Word的HWPF,在各种组件中目前只有用于操作Excel的HSSF相对成熟。

    Jakarta POI HSSF API组件

    HSSF(用于操作Excel的组件)提供给用户使用的对象在rg.apache.poi.hssf.usermodel包中,主要部分包括Excel对象,样式和格式,还有辅助操作。有以下几种对象:

    1.jpg

    基本操作步骤

    首先,理解一下一个Excel的文件的组织形式,一个Excel文件对应于一个workbook(HSSFWorkbook),一个workbook可以有多个sheet(HSSFSheet)组成,一个sheet是由多个row(HSSFRow)组成,一个row是由多个cell(HSSFCell)组成。

    基本操作步骤:

    2.jpg

    下面来看一个动态生成Excel文件的例子:

    //创建HSSFWorkbook对象
    HSSFWorkbook wb = new HSSFWorkbook();
    //创建HSSFSheet对象
    HSSFSheet sheet = wb.createSheet("sheet0");
    //创建HSSFRow对象
    HSSFRow row = sheet.createRow(0);
    //创建HSSFCell对象
    HSSFCell cell=row.createCell(0);
    //设置单元格的值
    cell.setCellValue("单元格中的中文");
    //输出Excel文件
    FileOutputStream output=new FileOutputStream("d:\\workbook.xls");
    wkb.write(output);
    output.flush();

    HSSF读取文件同样还是使用这几个对象,只是把相应的createXXX方法变成了getXXX方法即可。可见只要理解了其中原理,不管是读还是写亦或是特定格式都可以轻松实现,正所谓知其然更要知其所以然。

    导出表格的工具类:

    excelUtil:

    package com.zhl.push.Utils;
    
    import com.google.common.base.Strings;
    import org.apache.poi.hssf.usermodel.*;
    import org.apache.poi.hssf.util.HSSFColor;
    import org.apache.poi.ss.usermodel.VerticalAlignment;
    import org.apache.poi.ss.util.CellRangeAddress;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.math.BigDecimal;
    import java.util.List;
    import java.util.Map;
    
    public class ExcelExportUtil {
        //表头
        private String title;
        //各个列的表头
        private String[] heardList;
        //各个列的元素key值
        private String[] heardKey;
        //需要填充的数据信息
        private List<Map> data;
        //字体大小
        private int fontSize = 14;
        //行高
        private int rowHeight = 30;
        //列宽
        private int columWidth = 200;
        //工作表
        private String sheetName = "sheet1";
    
        public String getTitle() {
            return title;
        }
    
        public void setTitle(String title) {
            this.title = title;
        }
    
        public String[] getHeardList() {
            return heardList;
        }
    
        public void setHeardList(String[] heardList) {
            this.heardList = heardList;
        }
    
        public String[] getHeardKey() {
            return heardKey;
        }
    
        public void setHeardKey(String[] heardKey) {
            this.heardKey = heardKey;
        }
    
        public List<Map> getData() {
            return data;
        }
    
        public void setData(List<Map> data) {
            this.data = data;
        }
    
        public int getFontSize() {
            return fontSize;
        }
    
        public void setFontSize(int fontSize) {
            this.fontSize = fontSize;
        }
    
        public int getRowHeight() {
            return rowHeight;
        }
    
        public void setRowHeight(int rowHeight) {
            this.rowHeight = rowHeight;
        }
    
        public int getColumWidth() {
            return columWidth;
        }
    
        public void setColumWidth(int columWidth) {
            this.columWidth = columWidth;
        }
    
        public String getSheetName() {
            return sheetName;
        }
    
        public void setSheetName(String sheetName) {
            this.sheetName = sheetName;
        }
    
        /**
         * 开始导出数据信息
         *
         */
        public byte[] exportExport(HttpServletRequest request, HttpServletResponse response) throws IOException {
            //检查参数配置信息
            checkConfig();
            //创建工作簿
            HSSFWorkbook wb = new HSSFWorkbook();
            //创建工作表
            HSSFSheet wbSheet = wb.createSheet(this.sheetName);
            //设置默认行宽
            wbSheet.setDefaultColumnWidth(20);
    
            // 标题样式(加粗,垂直居中)
            HSSFCellStyle cellStyle = wb.createCellStyle();
            cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);//水平居中
            cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
            HSSFFont fontStyle = wb.createFont();
            fontStyle.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
            fontStyle.setBold(true);   //加粗
            fontStyle.setFontHeightInPoints((short)16);  //设置标题字体大小
            cellStyle.setFont(fontStyle);
    
            //在第0行创建rows  (表标题)
            HSSFRow title = wbSheet.createRow((int) 0);
            title.setHeightInPoints(30);//行高
            HSSFCell cellValue = title.createCell(0);
            cellValue.setCellValue(this.title);
            cellValue.setCellStyle(cellStyle);
            wbSheet.addMergedRegion(new CellRangeAddress(0,0,0,(this.heardList.length-1)));
            //设置表头样式,表头居中
            HSSFCellStyle style = wb.createCellStyle();
            //设置单元格样式
            style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
            style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
            //设置字体
            HSSFFont font = wb.createFont();
            font.setFontHeightInPoints((short) this.fontSize);
            style.setFont(font);
            //在第1行创建rows
            HSSFRow row = wbSheet.createRow((int) 1);
            //设置列头元素
            HSSFCell cellHead = null;
            for (int i = 0; i < heardList.length; i++) {
                cellHead = row.createCell(i);
                cellHead.setCellValue(heardList[i]);
                cellHead.setCellStyle(style);
            }
    
            //设置每格数据的样式 (字体红色)
            HSSFCellStyle cellParamStyle = wb.createCellStyle();
            HSSFFont ParamFontStyle = wb.createFont();
            cellParamStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
            cellParamStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
            ParamFontStyle.setColor(HSSFColor.DARK_RED.index);   //设置字体颜色 (红色)
            ParamFontStyle.setFontHeightInPoints((short) this.fontSize);
            cellParamStyle.setFont(ParamFontStyle);
            //设置每格数据的样式2(字体蓝色)
            HSSFCellStyle cellParamStyle2 = wb.createCellStyle();
            cellParamStyle2.setAlignment(HSSFCellStyle.ALIGN_CENTER);
            cellParamStyle2.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
            HSSFFont ParamFontStyle2 = wb.createFont();
            ParamFontStyle2.setColor(HSSFColor.BLUE.index);   //设置字体颜色 (蓝色)
            ParamFontStyle2.setFontHeightInPoints((short) this.fontSize);
            cellParamStyle2.setFont(ParamFontStyle2);
            //开始写入实体数据信息
            int a = 2;
            for (int i = 0; i < data.size(); i++) {
                HSSFRow roww = wbSheet.createRow((int) a);
                Map map = data.get(i);
                HSSFCell cell = null;
                for (int j = 0; j < heardKey.length; j++) {
                    cell = roww.createCell(j);
                    cell.setCellStyle(style);
                    Object valueObject = map.get(heardKey[j]);
                    String value = null;
                    if (valueObject == null) {
                        valueObject = "";
                    }
                    if (valueObject instanceof String) {
                        //取出的数据是字符串直接赋值
                        value = (String) map.get(heardKey[j]);
                    } else if (valueObject instanceof Integer) {
                        //取出的数据是Integer
                        value = String.valueOf(((Integer) (valueObject)).floatValue());
                    } else if (valueObject instanceof BigDecimal) {
                        //取出的数据是BigDecimal
                        value = String.valueOf(((BigDecimal) (valueObject)).floatValue());
                    } else {
                        value = valueObject.toString();
                    }
                    //设置单个单元格的字体颜色
                    if(heardKey[j].equals("ddNum") || heardKey[j].equals("sjNum")){
                    if((Long)map.get("ddNum")!=null){
                        if((Long)map.get("sjNum")==null){
                            cell.setCellStyle(cellParamStyle);
                        } else if((Long) map.get("ddNum") != (Long) map.get("sjNum")){
                            if ((Long) map.get("ddNum") > (Long) map.get("sjNum")) {
                                cell.setCellStyle(cellParamStyle);
                            }
                            if ((Long) map.get("ddNum") < (Long) map.get("sjNum")) {
                                cell.setCellStyle(cellParamStyle2);
                            }
                        }else {
                            cell.setCellStyle(style);
                        }
                    }
                    }
                    cell.setCellValue(Strings.isNullOrEmpty(value) ? "" : value);
                }
                a++;
            }
    
            //导出数据
            try {
                //设置Http响应头告诉浏览器下载这个附件
                response.setHeader("Content-Disposition", "attachment;Filename=" + System.currentTimeMillis() + ".xls");
                OutputStream outputStream = response.getOutputStream();
                wb.write(outputStream);
                outputStream.close();
                return wb.getBytes();
            } catch (Exception ex) {
                ex.printStackTrace();
                throw new IOException("导出Excel出现严重异常,异常信息:" + ex.getMessage());
            }
    
        }
    
        /**
         * 检查数据配置问题
         *
         * @throws IOException 抛出数据异常类
         */
        protected void checkConfig() throws IOException {
            if (heardKey == null || heardList.length == 0) {
                throw new IOException("列名数组不能为空或者为NULL");
            }
    
            if (fontSize < 0 || rowHeight < 0 || columWidth < 0) {
                throw new IOException("字体、宽度或者高度不能为负值");
            }
    
            if (Strings.isNullOrEmpty(sheetName)) {
                throw new IOException("工作表表名不能为NULL");
            }
        }
    }

    service :

    @Override
        public void queryProjectInfoBySchemeId(HttpServletResponse response, HttpServletRequest request,
                                                       String schemeId, String pushDate) throws IOException {
            List<Map> maps = pushMonitorDao.queryProjectInfoBySchemeId(schemeId, pushDate);
            if(maps!=null && maps.size()>0){
                 String companyName = pushMonitorDao.queryCompanyNameBySchemeId(schemeId);
                 String sheetTitle = companyName;
                 String [] title = new String[]{"城市","项目名字","合同","实际"};        //设置表格表头字段
                String [] properties = new String[]{"city","projectName","ddNum","sjNum"};  // 查询对应的字段
                ExcelExportUtil excelExport2 = new ExcelExportUtil();
                excelExport2.setData(maps);
                excelExport2.setHeardKey(properties);
                excelExport2.setFontSize(14);
                excelExport2.setSheetName(sheetTitle);
                excelExport2.setTitle(sheetTitle);
                excelExport2.setHeardList(title);
                excelExport2.exportExport(request, response);
             }
        }

    Excel格式

    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.lang.reflect.Field;
    import java.util.List;
    import java.util.logging.Level;
    import java.util.logging.Logger;
    import org.apache.poi.hssf.usermodel.HSSFCell;
    import org.apache.poi.hssf.usermodel.HSSFCellStyle;
    import org.apache.poi.hssf.usermodel.HSSFFont;
    import org.apache.poi.hssf.usermodel.HSSFRow;
    import org.apache.poi.hssf.usermodel.HSSFSheet;
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;
    import org.apache.poi.ss.usermodel.VerticalAlignment;
    import org.apache.poi.ss.util.CellRangeAddress;
    
    /**
     * @作者 yan
     * @创建日期
     * @版本 V1.0
     * @描述 Excel 导出通用工具类
     */
    public class ExcelUtil {
    
        public static byte[] export(String sheetTitle, String[] title, List<Object> list) {
    
            HSSFWorkbook wb = new HSSFWorkbook();//创建excel表
            HSSFSheet sheet = wb.createSheet(sheetTitle);
            sheet.setDefaultColumnWidth(20);//设置默认行宽
    
            //表头样式(加粗,水平居中,垂直居中)
            HSSFCellStyle cellStyle = wb.createCellStyle();
            cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);//水平居中
            cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
            //设置边框样式
            cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN); //下边框
            cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);//左边框
            cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);//上边框
            cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);//右边框
    
            HSSFFont fontStyle = wb.createFont();
            fontStyle.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
    
            cellStyle.setFont(fontStyle);
    
            //标题样式(加粗,垂直居中)
            HSSFCellStyle cellStyle2 = wb.createCellStyle();
            cellStyle2.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
            cellStyle2.setFont(fontStyle);
    
            //设置边框样式
            cellStyle2.setBorderBottom(HSSFCellStyle.BORDER_THIN); //下边框
            cellStyle2.setBorderLeft(HSSFCellStyle.BORDER_THIN);//左边框
            cellStyle2.setBorderTop(HSSFCellStyle.BORDER_THIN);//上边框
            cellStyle2.setBorderRight(HSSFCellStyle.BORDER_THIN);//右边框
    
            //字段样式(垂直居中)
            HSSFCellStyle cellStyle3 = wb.createCellStyle();
            cellStyle3.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
    
            //设置边框样式
            cellStyle3.setBorderBottom(HSSFCellStyle.BORDER_THIN); //下边框
            cellStyle3.setBorderLeft(HSSFCellStyle.BORDER_THIN);//左边框
            cellStyle3.setBorderTop(HSSFCellStyle.BORDER_THIN);//上边框
            cellStyle3.setBorderRight(HSSFCellStyle.BORDER_THIN);//右边框
    
            //创建表头
            HSSFRow row = sheet.createRow(0);
            row.setHeightInPoints(20);//行高
            
            HSSFCell cell = row.createCell(0);
            cell.setCellValue(sheetTitle);
            cell.setCellStyle(cellStyle);
    
            sheet.addMergedRegion(new CellRangeAddress(0,0,0,(title.length-1)));
            
            //创建标题
            HSSFRow rowTitle = sheet.createRow(1);
            rowTitle.setHeightInPoints(20);
    
            HSSFCell hc;
            for (int i = 0; i < title.length; i++) {
                hc = rowTitle.createCell(i);
                hc.setCellValue(title[i]);
                hc.setCellStyle(cellStyle2);
            }
    
            byte result[] = null;
    
            ByteArrayOutputStream out = null;
            
            try {
                //创建表格数据
                Field[] fields;
                int i = 2;
    
                for (Object obj : list) {
                    fields = obj.getClass().getDeclaredFields();
    
                    HSSFRow rowBody = sheet.createRow(i);
                    rowBody.setHeightInPoints(20);
    
                    int j = 0;
                    for (Field f : fields) {
    
                        f.setAccessible(true);
    
                        Object va = f.get(obj);
                        if (null == va) {
                            va = "";
                        }
    
                        hc = rowBody.createCell(j);
                        hc.setCellValue(va.toString());
                        hc.setCellStyle(cellStyle3);
                        
                        j++;
                    }
    
                    i++;
                }
    
                out = new ByteArrayOutputStream();
                wb.write(out);
                result =  out.toByteArray();
            } catch (Exception ex) {
                Logger.getLogger(ExcelUtil.class.getName()).log(Level.SEVERE, null, ex);
            } finally{
                try {
                    if(null != out){
                        out.close();
                    }
                } catch (IOException ex) {
                    Logger.getLogger(ExcelUtil.class.getName()).log(Level.SEVERE, null, ex);
                } finally{
                    try {
                        wb.close();
                    } catch (IOException ex) {
                        Logger.getLogger(ExcelUtil.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
            }
    
            return result;
        }
    }

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