最近公司项目有个需求，是导出列表中的数据并下载。如下图所示的列表数据，并且该数据不是一个表里的数据。

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实现步骤如下：本项目实现环境为maven项目
1.引入jia包：

2.拷贝ExportExcel文件和ReadExcel文件，是读取和导出excel文件的工具类，通用型的。
2.1 ReadExcel：
package dwz.plugins;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
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.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

/***** * @category 读取Excel文件的工具类 * @author yinzhifu * @version 2017-12-22 */ public class ReadExcel { public static List<List<Object>> readExcel(File file) throws IOException { String fName = file.getName(); String extension = fName.lastIndexOf(".") == -1 ? "" : fName.substring(fName.lastIndexOf(".") + 1); if ("xls".equals(extension)) {// 2003 System.err.println("读取excel2003文件内容"); return read2003Excel(file); } else if ("xlsx".equals(extension)) {// 2007 System.err.println("读取excel2007文件内容"); return read2007Excel(file); } else { throw new IOException("不支持的文件类型:" + extension); } } /** * 读取2003excel * * @param file * @return */ @SuppressWarnings("deprecation") private static List<List<Object>> read2003Excel(File file) throws IOException { List<List<Object>> dataList = new ArrayList<List<Object>>(); HSSFWorkbook wb = new HSSFWorkbook(new FileInputStream(file)); HSSFSheet sheet = wb.getSheetAt(0); HSSFRow row = null; HSSFCell cell = null; Object val = null; DecimalFormat df = new DecimalFormat("0");// 格式化数字 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// 格式化日期字符串 // 如果加1 则为去掉表头 for (int i = sheet.getFirstRowNum() + 1; i < sheet.getPhysicalNumberOfRows(); i++) { row = sheet.getRow(i); if (row == null) { continue; } List<Object> objList = new ArrayList<Object>(); for (int j = row.getFirstCellNum(); j < row.getLastCellNum(); j++) { cell = row.getCell(j); if (cell == null) { val = null; objList.add(val); continue; } switch (cell.getCellType()) { case HSSFCell.CELL_TYPE_STRING: val = cell.getStringCellValue(); break; case HSSFCell.CELL_TYPE_NUMERIC: if ("@".equals(cell.getCellStyle().getDataFormatString())) { val = df.format(cell.getNumericCellValue()); } else if ("General".equals(cell.getCellStyle().getDataFormatString())) { val = df.format(cell.getNumericCellValue()); } else { val = sdf.format(HSSFDateUtil.getJavaDate(cell.getNumericCellValue())); } break; case HSSFCell.CELL_TYPE_BOOLEAN: val = cell.getBooleanCellValue(); break; case HSSFCell.CELL_TYPE_BLANK: val = ""; break; default: val = cell.toString(); break; } objList.add(val); } dataList.add(objList); } return dataList; } /** * 读取excel表头 * * @param file * @return * @throws IOException */ public static String[] readExcelHead(File file) throws IOException { HSSFWorkbook wb = new HSSFWorkbook(new FileInputStream(file)); HSSFSheet sheet = wb.getSheetAt(0); HSSFRow row = null; HSSFCell cell = null; row = sheet.getRow(0); String[] buff = new String[row.getLastCellNum()]; for (int i = row.getFirstCellNum(); i < row.getLastCellNum(); i++) { cell = row.getCell(i); buff[i] = cell.getStringCellValue(); } return buff; } /** * 读取2007excel * * @param file * @return 文件内容 */ private static List<List<Object>> read2007Excel(File file) throws IOException { List<List<Object>> dataList = new ArrayList<List<Object>>(); XSSFWorkbook xwb = new XSSFWorkbook(new FileInputStream(file)); XSSFSheet sheet = xwb.getSheetAt(0); XSSFRow row = null; XSSFCell cell = null; Object val = null; DecimalFormat df = new DecimalFormat("0");// 格式化数字 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// 格式化日期字符串 // 如果开始位置加1 则不读取表头 for (int i = sheet.getFirstRowNum() + 1; i < sheet.getPhysicalNumberOfRows(); i++) { row = sheet.getRow(i); if (row == null) { continue; } List<Object> objList = new ArrayList<Object>(); for (int j = row.getFirstCellNum(); j < row.getLastCellNum(); j++) { cell = row.getCell(j); if (cell == null) { val = null; objList.add(val); continue; } switch (cell.getCellType()) { case XSSFCell.CELL_TYPE_STRING: val = cell.getStringCellValue(); break; case XSSFCell.CELL_TYPE_NUMERIC: if ("@".equals(cell.getCellStyle().getDataFormatString())) { val = df.format(cell.getNumericCellValue()); } else if ("General".equals(cell.getCellStyle().getDataFormatString())) { val = df.format(cell.getNumericCellValue()); } else { val = sdf.format(HSSFDateUtil.getJavaDate(cell.getNumericCellValue())); } break; case XSSFCell.CELL_TYPE_BOOLEAN: val = cell.getBooleanCellValue(); break; case XSSFCell.CELL_TYPE_BLANK: val = ""; break; default: val = cell.toString(); break; } objList.add(val); } dataList.add(objList); } return dataList; } /*** * 测试 * * @param args */ public static void readExcel() { try { List<List<Object>> list = readExcel(new File("F:\\1.xls")); int num = 1; for (List<Object> objList : list) { System.out.print(num + " "); for (Object obj : objList) { System.out.print(obj + "\t"); } System.out.println(); num++; } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } // 测试表头 public static void readHed() { String[] sArr; try { sArr = readExcelHead(new File("F:\\1.xls")); for (String s : sArr) { System.out.print(s + " "); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public static void main(String[] args) { readHed(); System.out.println("\n" + "-----------------"); readExcel(); } } 2.2 ExportExcel： package dwz.plugins; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.net.URLEncoder; import java.text.SimpleDateFormat; import java.util.Collection; import java.util.Date; import java.util.Iterator; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.servlet.http.HttpServletResponse; import org.apache.poi.hssf.usermodel.HSSFCell; import org.apache.poi.hssf.usermodel.HSSFCellStyle; import org.apache.poi.hssf.usermodel.HSSFClientAnchor; import org.apache.poi.hssf.usermodel.HSSFComment; import org.apache.poi.hssf.usermodel.HSSFFont; import org.apache.poi.hssf.usermodel.HSSFPatriarch; import org.apache.poi.hssf.usermodel.HSSFRichTextString; 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.hssf.util.HSSFColor; /**** * * @author yinzhfu * @category excel导出公共类 * @param <T> * @serial 2017-12-12 */ public class ExportExcel<T> { public void exportExcelCar(String[] headers, String sheetName, Collection<T> dataset, OutputStream out) { exportExcel(sheetName, headers, dataset, out, "yyyy-MM-dd"); } /** * 这是一个通用的方法，利用了JAVA的反射机制，可以将放置在JAVA集合中并且符号一定条件的数据以EXCEL 的形式输出到指定IO设备上 * * @param title * 表格标题名 * @param headers * 表格属性列名数组 * @param dataset * 需要显示的数据集合,集合中一定要放置符合javabean风格的类的对象。此方法支持的 * javabean属性的数据类型有基本数据类型及String,Date,byte[](图片数据) * @param out * 与输出设备关联的流对象，可以将EXCEL文档导出到本地文件或者网络中 * @param pattern * 如果有时间数据，设定输出格式。默认为"yyy-MM-dd" */ @SuppressWarnings({ "unchecked", "deprecation", "resource" }) public void exportExcel(String title, String[] headers, Collection<T> dataset, OutputStream out, String pattern) { // 声明一个工作薄 HSSFWorkbook workbook = new HSSFWorkbook(); // 生成一个表格 HSSFSheet sheet = workbook.createSheet(title); // 设置表格默认列宽度为15个字节 sheet.setDefaultColumnWidth((short) 15); // 生成一个样式 HSSFCellStyle style = workbook.createCellStyle(); // 设置这些样式 style.setFillForegroundColor(HSSFColor.SKY_BLUE.index); style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND); style.setBorderBottom(HSSFCellStyle.BORDER_THIN); style.setBorderLeft(HSSFCellStyle.BORDER_THIN); style.setBorderRight(HSSFCellStyle.BORDER_THIN); style.setBorderTop(HSSFCellStyle.BORDER_THIN); style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 生成一个字体 HSSFFont font = workbook.createFont(); font.setColor(HSSFColor.VIOLET.index); font.setFontHeightInPoints((short) 12); font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD); // 把字体应用到当前的样式 style.setFont(font); // 生成并设置另一个样式 HSSFCellStyle style2 = workbook.createCellStyle(); style2.setFillForegroundColor(HSSFColor.LIGHT_YELLOW.index); style2.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND); style2.setBorderBottom(HSSFCellStyle.BORDER_THIN); style2.setBorderLeft(HSSFCellStyle.BORDER_THIN); style2.setBorderRight(HSSFCellStyle.BORDER_THIN); style2.setBorderTop(HSSFCellStyle.BORDER_THIN); style2.setAlignment(HSSFCellStyle.ALIGN_CENTER); style2.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER); // 生成另一个字体 HSSFFont font2 = workbook.createFont(); font2.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL); // 把字体应用到当前的样式 style2.setFont(font2); // 声明一个画图的顶级管理器 HSSFPatriarch patriarch = sheet.createDrawingPatriarch(); // 定义注释的大小和位置,详见文档 HSSFComment comment = patriarch.createComment(new HSSFClientAnchor(0, 0, 0, 0, (short) 4, 2, (short) 6, 5)); // 设置注释内容 comment.setString(new HSSFRichTextString("可以在POI中添加注释！")); // 设置注释作者，当鼠标移动到单元格上是可以在状态栏中看到该内容. comment.setAuthor("leno"); // 产生表格标题行 HSSFRow row = sheet.createRow(0); for (short i = 0; i < headers.length; i++) { HSSFCell cell = row.createCell(i); cell.setCellStyle(style); HSSFRichTextString text = new HSSFRichTextString(headers[i]); cell.setCellValue(text); } // 遍历集合数据，产生数据行 Iterator<T> it = dataset.iterator(); int index = 0; while (it.hasNext()) { index++; row = sheet.createRow(index); T t = (T) it.next(); // 利用反射，根据javabean属性的先后顺序，动态调用getXxx()方法得到属性值 Field[] fields = t.getClass().getDeclaredFields(); for (short i = 0; i < fields.length; i++) { HSSFCell cell = row.createCell(i); cell.setCellStyle(style2); Field field = fields[i]; String fieldName = field.getName(); String getMethodName = "get" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1); try { Class tCls = t.getClass(); Method getMethod = tCls.getMethod(getMethodName, new Class[] {}); Object value = getMethod.invoke(t, new Object[] {}); // 判断值的类型后进行强制类型转换 String textValue = null; if (value instanceof Boolean) { boolean bValue = (Boolean) value; textValue = "男"; if (!bValue) { textValue = "女"; } } else if (value instanceof Date) { Date date = (Date) value; SimpleDateFormat sdf = new SimpleDateFormat(pattern); textValue = sdf.format(date); } else if (value instanceof byte[]) { // 有图片时，设置行高为60px; row.setHeightInPoints(60); // 设置图片所在列宽度为80px,注意这里单位的一个换算 sheet.setColumnWidth(i, (short) (35.7 * 80)); // sheet.autoSizeColumn(i); byte[] bsValue = (byte[]) value; HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0, 1023, 255, (short) 6, index, (short) 6, index); anchor.setAnchorType(2); patriarch.createPicture(anchor, workbook.addPicture(bsValue, HSSFWorkbook.PICTURE_TYPE_JPEG)); } else { // 其它数据类型都当作字符串简单处理 if (null == value) { textValue = ""; } else { textValue = value.toString(); } } // 如果不是图片数据，就利用正则表达式判断textValue是否全部由数字组成 if (textValue != null) { Pattern p = Pattern.compile("^//d+(//.//d+)?$"); Matcher matcher = p.matcher(textValue); if (matcher.matches()) { // 是数字当作double处理 cell.setCellValue(Double.parseDouble(textValue)); } else { HSSFRichTextString richString = new HSSFRichTextString(textValue); HSSFFont font3 = workbook.createFont(); font3.setColor(HSSFColor.BLUE.index); richString.applyFont(font3); cell.setCellValue(richString); } } } catch (SecurityException e) { e.printStackTrace(); } catch (NoSuchMethodException e) { e.printStackTrace(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } finally { // 清理资源 } } } try { workbook.write(out); } catch (IOException e) { e.printStackTrace(); } } /*** * @category 下载excel文件公共方法 * * @param path * 文件所在路径 * @param response */ public void download(String path, HttpServletResponse response) { try { // path是指欲下载的文件的路径。 File file = new File(path); // 取得文件名。 String name = file.getName(); String filename = URLEncoder.encode(name, "UTF-8"); // 以流的形式下载文件。 InputStream fis = new BufferedInputStream(new FileInputStream(path)); byte[] buffer = new byte[fis.available()]; fis.read(buffer); fis.close(); // 清空response response.reset(); // 设置response的Header response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes())); response.addHeader("Content-Length", "" + file.length()); OutputStream toClient = new BufferedOutputStream(response.getOutputStream()); response.setContentType("application/vnd.ms-excel;charset=UTF-8"); toClient.write(buffer); toClient.flush(); toClient.close(); } catch (IOException ex) { ex.printStackTrace(); } } }

3.controller 部分截图如下：

4.service 部分截图如下：

6.dao 部分截图如下：

7.mapper.xml部分截图如下：

8.还有个关键点，如下图所示：