apache POI导出excel文件 及单元格合并 、样式的设置

客户需要从完单物料信息中到处excel
大概思路：
单击某一按钮，触发请求至后台，创建输出流，导出excel ^_^ 
 

前台代码：
（此段代码 注释部分存在一个问题，注释部分的请求无效，后台无法响应前台请求，
参数传过去了，后台也接受了，但输出流没有输出，木鸡why）解决方法，用一个重定向代替这个框架sendRequest发送请求。

isc.IButton.create({	ID:"excelBtn",	width:"80",	height:"25",	icon:"demoApp/page_excel.png",	title:"導出excel",	click:function(){		var length = DataList.getSelectedRecords().getLength();    	if(length>0){			var projEndId = DataList.getSelectedRecord().projEndId;			window.location='com/el/ProjectEnd/createPeSystemReport.action?projEndId=' + projEndId;//		    RPCManager.sendRequest({//		        actionURL:"com/el/ProjectEnd/createPeSystemReport.action",//		        params:{projEndId:projEndId},//		        callback:function() {isc.say("報表導入成功");}//		    });    	}else{    		isc.say("請選擇要導出的項目");    		    	}	}});后台代码在web层（controller）写一个方法，在此方法内获取信息数据源，创建输出流，然后调用生成excel的函数，关闭输出流。//----------導出excel報----------------------------------		@RequestMapping(value = "com/el/ProjectEnd/createPeSystemReport.action")	public void exportExecl(HttpServletRequest request, HttpServletResponse response) {				int projEndId = Integer.parseInt(request.getParameter("projEndId"));				System.out.println("projEndId--:"+projEndId);		List<ProjItemSumLine> list = projItemSumLineService.findProjLineByProjEndId(projEndId);		ProjItemSumHead projItemSumHead = this.projItemSumHeadService.findProjItemSumHeadByProjEndId(projEndId);				response.setContentType("application/vnd.ms-excel");		response.setHeader("Content-Disposition", "attachment; filename=PEMaterialSummary.xls; target=_blank");		String ppc_ = "PPC";		String pmc_ = "PMC";		String purchaser_ = "Purchaser";//採購		String engineer_ = "Engineer";				String ppc = this.projItemSumLiabUserService.findProjItemSumLiabUserName(projEndId, ppc_);		String pmc = this.projItemSumLiabUserService.findProjItemSumLiabUserName(projEndId, pmc_);		String purchaser = this.projItemSumLiabUserService.findProjItemSumLiabUserName(projEndId, purchaser_);		String enginer = this.projItemSumLiabUserService.findProjItemSumLiabUserName(projEndId, engineer_);				ExportToExecl ete = new ExportToExecl();		OutputStream os = ete.exportMaterialSummary(list,projItemSumHead,ppc,pmc,purchaser,enginer, response);		try {			if(os != null){				os.flush();				os.close();			}		} catch (IOException e) {				e.printStackTrace();		}			}}生成excel的函数：返回OutputStream类型package com.el.pe.util.export;import java.io.IOException;import java.io.OutputStream;import java.util.HashMap;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.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.hssf.util.CellRangeAddress;import org.apache.poi.ss.usermodel.IndexedColors;import com.el.pe.model.ProjItemSumHead;import com.el.pe.model.ProjItemSumLine;public class ExportToExecl {	public OutputStream exportMaterialSummary(List<ProjItemSumLine> list, ProjItemSumHead projItemSumHead,String ppc,String pmc,String purchaser,String enginer,HttpServletResponse response) {				HSSFWorkbook workbook = new HSSFWorkbook();		HSSFSheet itemSheet = workbook.createSheet("PEMaterialSummary");		int rownum = 2;// 第二行開始		String cellTitle[] = {"列名"};		Map<String, HSSFCellStyle> styles = ExportToExecl.createStyles(workbook);				HSSFRow row_first_header = itemSheet.createRow(rownum++);		HSSFCell cell_title = null;		//創建列名		for (int i = 0; i < cellTitle.length; i++) {			itemSheet.setColumnWidth(i, 18 * 256);			row_first_header.setHeight((short) (2 * 356));			cell_title = row_first_header.createCell(i);			cell_title.setCellType(HSSFCell.CELL_TYPE_STRING);			cell_title.setCellStyle(styles.get("cell_header_title"));			cell_title.setCellValue(cellTitle[i]);		}		//合併單元格 四个参数分别为：开始行开始列，结束行结束列//		itemSheet.addMergedRegion(new CellRangeAddress(0,(short)0,1,(short)0)); //		itemSheet.addMergedRegion(new CellRangeAddress((short)1, (short)1, (short)2, (short)2));				//写入数据		HSSFRow row_data = null;		HSSFCell cell_data = null;		for(int j =0;j<list.size();j++){		 			for(int i = 0 ;i<cellTitle.length;i++){		 //此处省略N个字		}		try {			OutputStream os = response.getOutputStream();			workbook.write(os);			return os;		} catch (IOException e) {			e.printStackTrace();		}		return null;	}		/*----------創建excel styles----------------------------------*/	private static Map<String, HSSFCellStyle> createStyles(HSSFWorkbook wb) {		Map<String, HSSFCellStyle> styles = new HashMap<String, HSSFCellStyle>();		//----------------------標題樣式---------------------------		HSSFCellStyle cell_header_title = wb.createCellStyle();		HSSFFont font_header_title = wb.createFont();		font_header_title.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);// 粗體		font_header_title.setFontHeight((short) (9 * 20));		font_header_title.setFontName("Times New Roman");// 字體樣式		cell_header_title.setFont(font_header_title);		cell_header_title.setAlignment(HSSFCellStyle.ALIGN_CENTER);// 居中		cell_header_title.setWrapText(true);		styles.put("cell_header_title", cell_header_title);				//-----------------------設置字符樣式---------------------------				HSSFCellStyle cell_data_default = wb.createCellStyle();		HSSFFont font_data_default = wb.createFont();		font_data_default.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);		font_data_default.setFontHeight((short) (8 * 20));		font_data_default.setFontName("Arial Narrow");// 字體樣式		cell_data_default.setFont(font_data_default);		cell_data_default.setAlignment(HSSFCellStyle.ALIGN_LEFT);// 居中		cell_data_default.setWrapText(true);// 自動換行		styles.put("cell_data_default", cell_data_default);						return styles;	}}