POI导入导出excel公用方法

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.text.DecimalFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;

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.HSSFDateUtil;
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.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExcelUtil {
	/** Excel 文件要存放的位置，假定在D盘下 */
	public static String outputFile = "D:\\test1.xls";
	public static String fileToBeRead="D:\\test.xls";
	/**
	 * 
	 * 描述：导出excel文件
	 * @param list：实体类的集合
	 * @param name：导出excel文件的文件名
	 * @param columnName：要导出的列名（开头第一个字母大写）
	 * @param columnTitle 列名对应的标题
	 * @param ClassName 列中包含的引用对象的类名（前后需加逗号分隔，要求是需要取的值必须是该引用对象的Name属性且名字应与该对象属性名字一致，如要取Department dept对象的deptName属性，则该参数为',Department,'）
	 */
	public static void Export(HttpServletResponse response,List<?> list, String name, String[] columnName, String[] columnTitle,String ClassName){
		OutputStream os = null;
		//输出到输出流，让用户下载
		try {
			response.setHeader("Content-disposition", "attachment; filename="
			           + new String(name.getBytes("GB2312"), "ISO8859-1")
			           + ".xls");
			response.setContentType("application/msexcel");
			os = response.getOutputStream();
		} catch (IOException e1) {
			e1.printStackTrace();
		}
		//输出到指定文件
		/*OutputStream os = null;
		try {
			os = new FileOutputStream(new File("d:/"+name+".xls"));
		} catch (FileNotFoundException e1) {
			e1.printStackTrace();
		}*/
		Class<?> bean = list.get(0).getClass();
		//新建excel
		HSSFWorkbook workbook = new HSSFWorkbook();
		//得到实体类的名字，作为工作表的名字
		String bean_name = bean.getName();
		bean_name = bean_name.substring(bean_name.lastIndexOf(".")+1);
		//第一张工作表
		HSSFSheet sheet = workbook.createSheet(bean_name);
		//设置字体样式
		HSSFFont font = workbook.createFont();
		font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
		HSSFCellStyle cellStyle= workbook.createCellStyle();
		cellStyle.setFont(font);
		//设置Excel表头，如果标题为null则用列名代替标题  
		if(columnTitle==null){
			columnTitle = columnName;
		}
		HSSFRow firstrow = sheet.createRow(0); // 下标为0的行开始 
		for (int i = 0; i < columnTitle.length; i++) {
			HSSFCell title = firstrow.createCell(i);
			title.setCellStyle(cellStyle);
			title.setCellValue(columnTitle[i]);
		}
		String value;
		SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
		try{
			for(int t = 0;t < list.size();t++){
				Object b = list.get(t);
				HSSFRow cotent = sheet.createRow(t + 1);
				for(int i=0;i<columnName.length;i++){
					Method method = bean.getMethod("get"+columnName[i]);
					//判断是否是日期属性
					Object o = method.invoke(b);
					if(o!=null){
						if(o instanceof Date){
							value = format.format(format.parse(o.toString()));
						}else{
							if(ClassName !=null && !"".equals(ClassName) && ClassName.indexOf(","+o.getClass().getSimpleName()+",") != -1){
								value = o.getClass().getMethod("get"+columnName[i]+"Name").invoke(o).toString();
							}else{
								value = o.toString();
							}
						}
					}else{
						value="";
					}
					HSSFCell contentDetail = cotent.createCell(i);
					contentDetail.setCellValue(value);
				}
			}
			workbook.write(os);
			os.flush();
			os.close();
		}catch(Exception e){
			e.printStackTrace();
		}
	}
	/**
	 * 
	 * 描述：导入excel文件
	 * @param i_class：导入的文件中存放实体类的class
	 * @param file：需要导入的文件
	 * @param map：导入的模板（excel里的表头和实体类里的列对应）
	 * @param isExcel2003：判断excel文件是否为2003版本
	 * @return 返回值若为String则表示有错误，若为集合则为将excel中数据填充后的实体类集合
	 */
	public static Object Import(Class<?> i_class,Map<String,String> map, File file,boolean isExcel2003){
		//存储实体的集合
		List<Object> list = new ArrayList<Object>();
		//错误数
		int wrong=0;
		//标题数组
		String[] attrs = null;
		String[] attrsChildren = null;
		//错误消息
		StringBuffer message = new StringBuffer();
		SimpleDateFormat format = new SimpleDateFormat("yyyy-M-d");
		SimpleDateFormat format2 = new SimpleDateFormat("yyyy/M/d");
		DecimalFormat df = new DecimalFormat("0");  
		try {
			//根据文件得到workbook对象
			Workbook workbook = null;
			if(isExcel2003){
				//2003
				workbook = new HSSFWorkbook(new FileInputStream(file));	
			}else{
				//2007
				workbook = new XSSFWorkbook(new FileInputStream(file));
			}
			 
			//得到sheet工作表的数量
			int sheetNumber = workbook.getNumberOfSheets();
			//存储各个工作表标题的集合
			List<String[]> ColNames=new ArrayList<String[]>();
			//验证列名
			StringBuffer wrongCols = new StringBuffer("出错列名为：");
			int size = 0;
			Sheet sheet = workbook.getSheetAt(size);
			String content;
			while(sheet != null){
				Row row = sheet.getRow(0);
				if(row != null){
					int rowNum = (int)row.getLastCellNum();
					attrs = new String[rowNum];
					int isNull = 0;
					for(int i = 0;i < rowNum;i++){
						Cell cell = row.getCell(i);
						content = cell.getStringCellValue();
						if(content != null && !"".equals(content)){
							isNull++;
							if(!map.containsKey(content)){
								wrongCols.append(content+",");
							}else{
								attrs[i]=map.get(content);
							}
						}
					}
					attrsChildren = new String[isNull];
					for(int t = 0;t < isNull;t++){
						attrsChildren[t] = attrs[t];
					}
					attrs = attrsChildren;
					ColNames.add(attrs);
				}
				size++;
				if(size >= (sheetNumber - 1)){
					break;
				}
				sheet = workbook.getSheetAt(size);
			}
			if(!wrongCols.toString().equals("出错列名为：")){
				return wrongCols.subSequence(0, wrongCols.length() - 1);
			}
			//验证数据类型
			String MethodName;
			Method method;
			size = 0;
			sheet = workbook.getSheetAt(size);
			String oldContent;
			Date dateValue;
			while(sheet != null){
				oldContent = message.toString();
				int rowNum = 1;
				Row row = sheet.getRow(rowNum++);
				if(row == null){
					size++;
					if(size >= (sheetNumber - 1)){
						break;
					}
					sheet = workbook.getSheetAt(size);
					continue;
				}
				attrs = ColNames.get(size);
				Cell cell = null;
				while(row != null && row.getLastCellNum() > 0){
					for(int i=0;i<attrs.length;i++){
						dateValue = null;
						cell = row.getCell(i);
						String contentDetail = "";
						if (null != cell){
							// 以下是判断数据的类型  
							switch (cell.getCellType()){
								case HSSFCell.CELL_TYPE_NUMERIC: // 数字 
									//判断是否是日期类型
									if(HSSFDateUtil.isCellDateFormatted(cell)){
										dateValue = cell.getDateCellValue();
									}else{
										contentDetail = cell.getNumericCellValue() + "";
									}
			                        break;
			                    case HSSFCell.CELL_TYPE_STRING: // 字符串 
			                    	contentDetail = cell.getStringCellValue();
			                        break;
			                    case HSSFCell.CELL_TYPE_BOOLEAN: // Boolean
			                    	contentDetail = cell.getBooleanCellValue() + "";
			                        break;
			                    case HSSFCell.CELL_TYPE_FORMULA: // 公式 
			                    	contentDetail = cell.getCellFormula() + "";
			                        break;
			                    case HSSFCell.CELL_TYPE_BLANK: // 空值 
			                    	contentDetail = "";
			                        break;
			                    case HSSFCell.CELL_TYPE_ERROR: // 故障 
			                    	contentDetail = "";
			                        break;
			                    default:
			                    	contentDetail = "";
			                        break;
							}
						} 
						if(i > (row.getLastCellNum() - 1) || contentDetail == null || "".equals(contentDetail)){
							size++;
							if(size >= (sheetNumber - 1)){
								break;
							}
							sheet = workbook.getSheetAt(size);
							continue;
						}
						MethodName = "set"+attrs[i];
						//Integer类型
						try{
							method = i_class.getMethod(MethodName,Integer.class);
							Integer.parseInt(contentDetail);
							continue;
						}catch(NoSuchMethodException e){
							
						}catch(Exception e){
							wrong++;
							if(message.indexOf("第" + row.getRowNum() + "张工作表：") == -1){
								message.append("第" + row.getRowNum() + "张工作表：");
							}
							message.append(attrs[i] + "列，"+ rowNum + "行；");
							continue;
						}
						//Double类型
						try{
							method = i_class.getMethod(MethodName, Double.class);
							Double.parseDouble(contentDetail);
							continue;
						}catch(NoSuchMethodException e){
							
						}catch(Exception e1){
							wrong++;
							if(message.indexOf("第" + row.getRowNum() + "张工作表：") == -1){
								message.append("第" + row.getRowNum() + "张工作表：");
							}
							message.append(attrs[i] + "列，" + rowNum + "行；");
							continue;
						}
						//Date类型
						try{
							method = i_class.getMethod(MethodName, Date.class);
							if(dateValue == null){
								try{
									format.parse(contentDetail);
								}catch(ParseException e){
									format2.parse(contentDetail);
								}
							}
							continue;
						}catch(NoSuchMethodException e){
							
						}catch(Exception e2){
							wrong++;
							if(message.indexOf("第" + row.getRowNum() + "张工作表：") == -1){
								message.append("第" + row.getRowNum() + "张工作表：");
							}
							message.append(attrs[i] + "列，" + rowNum + "行；");
							continue;
						}
						//String类型
						try{
							method = i_class.getMethod(MethodName, String.class);
						}catch(NoSuchMethodException e){
							wrong++;
							if(message.indexOf("第" + row.getRowNum() + "张工作表：") == -1){
								message.append("第" + row.getRowNum() + "张工作表：");
							}
							message.append(attrs[i] + "列，" + rowNum + "行；");
						}
					}
					row = sheet.getRow(rowNum++);
				}
				if(!message.toString().equals(oldContent)){
					message.append("<br />");
				}
				size++;
				if(size >= (sheetNumber - 1)){
					break;
				}
				sheet = workbook.getSheetAt(size);
			}
			if(wrong>0){
				return "数据出错总数为：" + wrong + "<br />分别为：" + message.toString();
			}
			size = 0;
			sheet = workbook.getSheetAt(size);
			Cell cell = null;
			while(sheet != null){
				if(size >= ColNames.size()){
					break;
				}
				attrs = ColNames.get(size);
				int rowNum = 1;
				Row row = sheet.getRow(rowNum++);
				while(row != null && row.getLastCellNum() > 0){
					//此处可增加判断行为空行是跳过的代码
					Object o = i_class.newInstance();
					for(int i=0;i<attrs.length;i++){
						dateValue = null;
						cell = row.getCell(i);
						String contentDetail = "";
						if (null != cell){
							// 以下是判断数据的类型  
							switch (cell.getCellType()){
								case HSSFCell.CELL_TYPE_NUMERIC: // 数字 
									//判断是否是日期类型，若是则转为字符串，因为有可能数据类型为String
									if(HSSFDateUtil.isCellDateFormatted(cell)){
										dateValue = cell.getDateCellValue();
										contentDetail = format.format(dateValue);
									}else{
										contentDetail = df.format(cell.getNumericCellValue());  
									}
			                        break;
			                    case HSSFCell.CELL_TYPE_STRING: // 字符串 
			                    	contentDetail = cell.getStringCellValue();
			                        break;
			                    case HSSFCell.CELL_TYPE_BOOLEAN: // Boolean
			                    	contentDetail = cell.getBooleanCellValue() + "";
			                        break;
			                    case HSSFCell.CELL_TYPE_FORMULA: // 公式 
			                    	contentDetail = cell.getCellFormula() + "";
			                        break;
			                    case HSSFCell.CELL_TYPE_BLANK: // 空值 
			                    	contentDetail = "";
			                        break;
			                    case HSSFCell.CELL_TYPE_ERROR: // 故障 
			                    	contentDetail = "";
			                        break;
			                    default:
			                    	contentDetail = "";
			                        break;
							}
						}
						if(i > (row.getLastCellNum() - 1) || contentDetail == null || "".equals(contentDetail)){
							continue;
						}
						MethodName = "set"+attrs[i];
						//得到该属性对应的set方法，参数有可能是Integer、Double、Date、String
						try{
							method = i_class.getMethod(MethodName,Integer.class);
							method.invoke(o, Integer.parseInt(contentDetail));
						}catch(Exception e){
							try{
								method = i_class.getMethod(MethodName, Double.class);
								method.invoke(o, Double.parseDouble(contentDetail));
							}catch(Exception e1){
								try{
									method = i_class.getMethod(MethodName, Date.class);
									if(dateValue != null){
										method.invoke(o, dateValue);
									}else{
										try{
											method.invoke(o, format.parse(contentDetail));
										}catch(ParseException pe){
											method.invoke(o, format2.parse(contentDetail));
										}
									}
									
								}catch(Exception e2){
									method = i_class.getMethod(MethodName, String.class);
									method.invoke(o, contentDetail);
								}
							}
						}
					}
					list.add(o);
					row = sheet.getRow(rowNum++);
				}
				size++;
				if(size >= (sheetNumber - 1)){
					break;
				}
				sheet = workbook.getSheetAt(size);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return list;
	}
	public static void main(String argv[]) {
		/*List<Level> l_list = new ArrayList<Level>();
		for(int i=1;i<=10;i++){
			Level level = new Level(i,"LevelName" + i,"LevelDesc" + i,i);
			l_list.add(level);
		}
		String[] columnName = {"LevelId","LevelName","LevelDesc","LevelOrder"};
		String[] columnTitle = {"级别ID","级别名称","级别描述","级别重要顺序"};
		Export(null,l_list,"POI",columnName,columnTitle,null);
		Map<String,String> map = new HashMap<String,String>();
		map.put("级别ID", "LevelId");
		map.put("级别名称", "LevelName");
		map.put("级别描述", "LevelDesc");
		map.put("级别重要顺序", "LevelOrder");
		Object o = Import(Level.class,map,new File("d:/POI.xls"),true);
		if(o instanceof String){
			System.out.println(o.toString());
		}else{
			List<Level> test = (List<Level>)o;
			for(Level l : test){
				System.out.println(l.getLevelName());
			}
		}*/
	}
}

 用POI实现的导入导出excel的公用类，根据反射实现，导入的方法由于判断有效性略麻烦。。。