第一步：

package com.wlsq.kso.util;
import org.apache.poi.hssf.usermodel.*;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.util.Calendar;  
import java.util.List;  
import java.util.Map;  
  
/** 
 * poi 匯出excel 工具類 
 */  
public class POIUtil {  
  
    /** 
     * 1.建立 workbook 
     * @return 
     */  
    public HSSFWorkbook getHSSFWorkbook(){  
        return new HSSFWorkbook();  
    }  
  
    /** 
     * 2.建立 sheet 
     * @param hssfWorkbook 
     * @param sheetName sheet 名稱 
     * @return 
     */  
    public HSSFSheet getHSSFSheet(HSSFWorkbook hssfWorkbook, String sheetName){  
        return hssfWorkbook.createSheet(sheetName);  
    }  
  
    /** 
     * 3.寫入表頭資訊 
     * @param hssfWorkbook 
     * @param hssfSheet 
     * @param headInfoList List<Map<String, Object>> 
     *              key: title         列標題 
     *                   columnWidth   列寬 
     *                   dataKey       列對應的 dataList item key 
     */  
    public void writeHeader(HSSFWorkbook hssfWorkbook,HSSFSheet hssfSheet ,List<Map<String, Object>> headInfoList){  
        HSSFCellStyle cs = hssfWorkbook.createCellStyle();  
        HSSFFont font = hssfWorkbook.createFont();  
        font.setFontHeightInPoints((short)12);  
        font.setBoldweight(font.BOLDWEIGHT_BOLD);  
        cs.setFont(font);  
        cs.setAlignment(cs.ALIGN_CENTER);  
  
        HSSFRow r = hssfSheet.createRow(0);  
        r.setHeight((short) 380);  
        HSSFCell c = null;  
        Map<String, Object> headInfo = null;  
        //處理excel表頭  
        for(int i=0, len = headInfoList.size(); i < len; i++){  
            headInfo = headInfoList.get(i);  
            c = r.createCell(i);  
            c.setCellValue(headInfo.get("title").toString());  
            c.setCellStyle(cs);  
            if(headInfo.containsKey("columnWidth")){  
                hssfSheet.setColumnWidth(i, (short)(((Integer)headInfo.get("columnWidth") * 8) / ((double) 1 / 20)));  
            }  
        }  
    }  
  
    /** 
     * 4.寫入內容部分 
     * @param hssfWorkbook 
     * @param hssfSheet 
     * @param startIndex 從1開始，多次呼叫需要加上前一次的dataList.size() 
     * @param headInfoList List<Map<String, Object>> 
     *              key: title         列標題 
     *                   columnWidth   列寬 
     *                   dataKey       列對應的 dataList item key 
     * @param dataList 
     */  
    public void writeContent(HSSFWorkbook hssfWorkbook,HSSFSheet hssfSheet ,int startIndex,  
                                     List<Map<String, Object>> headInfoList, List<Map<String, Object>> dataList){  
        Map<String, Object> headInfo = null;  
        HSSFRow r = null;  
        HSSFCell c = null;  
        //處理資料  
        Map<String, Object> dataItem = null;  
        Object v = null;  
        for (int i=0, rownum = startIndex, len = (startIndex + dataList.size()); rownum < len; i++,rownum++){  
            r = hssfSheet.createRow(rownum);  
            r.setHeightInPoints(16);  
            dataItem = dataList.get(i);  
            for(int j=0, jlen = headInfoList.size(); j < jlen; j++){  
                headInfo = headInfoList.get(j);  
                c = r.createCell(j);  
                v = dataItem.get(headInfo.get("dataKey").toString());  
  
                if (v instanceof String) {  
                    c.setCellValue((String)v);  
                }else if (v instanceof Boolean) {  
                    c.setCellValue((Boolean)v);  
                }else if (v instanceof Calendar) {  
                    c.setCellValue((Calendar)v);  
                }else if (v instanceof Double) {  
                    c.setCellValue((Double)v);  
                }else if (v instanceof Integer  
                        || v instanceof Long  
                        || v instanceof Short  
                        || v instanceof Float) {  
                    c.setCellValue(Double.parseDouble(v.toString()));  
                }else if (v instanceof HSSFRichTextString) {  
                    c.setCellValue((HSSFRichTextString)v);  
                }else {  
                    c.setCellValue(v.toString());  
                }  
            }  
        }  
    }  
  
    public void write2FilePath(HSSFWorkbook hssfWorkbook, String filePath) throws IOException{  
        FileOutputStream fileOut = null;  
        try{  
            fileOut = new FileOutputStream(filePath);  
            hssfWorkbook.write(fileOut);  
        }finally{  
            if(fileOut != null){  
                fileOut.close();  
            }  
        }  
    }  
  
  
    /** 
     * 匯出excel 
     * code example: 
         List<Map<String, Object>> headInfoList = new ArrayList<Map<String,Object>>(); 
         Map<String, Object> itemMap = new HashMap<String, Object>(); 
         itemMap.put("title", "序號1"); 
         itemMap.put("columnWidth", 25); 
         itemMap.put("dataKey", "XH1"); 
         headInfoList.add(itemMap); 
 
         itemMap = new HashMap<String, Object>(); 
         itemMap.put("title", "序號2"); 
         itemMap.put("columnWidth", 50); 
         itemMap.put("dataKey", "XH2"); 
         headInfoList.add(itemMap); 
 
         itemMap = new HashMap<String, Object>(); 
         itemMap.put("title", "序號3"); 
         itemMap.put("columnWidth", 25); 
         itemMap.put("dataKey", "XH3"); 
         headInfoList.add(itemMap); 
 
         List<Map<String, Object>> dataList = new ArrayList<Map<String,Object>>(); 
         Map<String, Object> dataItem = null; 
         for(int i=0; i < 100; i++){ 
         dataItem = new HashMap<String, Object>(); 
         dataItem.put("XH1", "data" + i); 
         dataItem.put("XH2", 88888888f); 
         dataItem.put("XH3", "脈兜V5.."); 
         dataList.add(dataItem); 
         } 
         POIUtil.exportExcel2FilePath("test sheet 1","F:\\temp\\customer2.xls", headInfoList, dataList); 
 
     * @param sheetName   sheet名稱 
     * @param filePath   檔案儲存路徑， 如：f:/a.xls 
     * @param headInfoList List<Map<String, Object>> 
     *                           key: title         列標題 
     *                                columnWidth   列寬 
     *                                dataKey       列對應的 dataList item key 
     * @param dataList  List<Map<String, Object>> 匯出的資料 
     * @throws java.io.IOException 
     * 
     */  
    public static void exportExcel2FilePath(String sheetName, String filePath,  
                                   List<Map<String, Object>> headInfoList,  
                                   List<Map<String, Object>> dataList) throws IOException {  
        POIUtil poiUtil = new POIUtil();  
        //1.建立 Workbook  
        HSSFWorkbook hssfWorkbook = poiUtil.getHSSFWorkbook();  
        //2.建立 Sheet  
        HSSFSheet hssfSheet = poiUtil.getHSSFSheet(hssfWorkbook, sheetName);  
        //3.寫入 head  
        poiUtil.writeHeader(hssfWorkbook, hssfSheet, headInfoList);  
        //4.寫入內容  
        poiUtil.writeContent(hssfWorkbook, hssfSheet, 1, headInfoList, dataList);  
        //5.儲存檔案到filePath中  
        poiUtil.write2FilePath(hssfWorkbook, filePath);  
    }  
  
}  
 

/*開發者資料匯出功能*/
	@RequestMapping(value = "/develop_export.action")
	@ResponseBody
	public void Export(HttpServletRequest request) throws IOException {	
		Developer developer = new Developer();
        Integer pageNum = 1;
		if (request.getParameter("pageNum") != null) {
			pageNum = Integer.parseInt(request.getParameter("pageNum"));					
		}
		developer.setPageNum((pageNum - 1) * 10);
		developer.setPageSize(10);
		List<Developer> develpers = developerService
				.selectByDevelopers(developer);
		
		 List<Map<String, Object>> headInfoList = new ArrayList<Map<String,Object>>(); 
         Map<String, Object> itemMap = new HashMap<String, Object>(); 
         itemMap.put("title", "開發者編號"); 
         itemMap.put("columnWidth", 25); 
         itemMap.put("dataKey", "XH1"); 
         headInfoList.add(itemMap); 
         
         itemMap = new HashMap<String, Object>(); 
         itemMap.put("title", "賬戶"); 
         itemMap.put("columnWidth", 50); 
         itemMap.put("dataKey", "XH2"); 
         headInfoList.add(itemMap); 
         
         itemMap = new HashMap<String, Object>(); 
         itemMap.put("title", "唯一編號"); 
         itemMap.put("columnWidth", 50); 
         itemMap.put("dataKey", "XH3"); 
         headInfoList.add(itemMap); 
 
         itemMap = new HashMap<String, Object>(); 
         itemMap.put("title", "真實姓名"); 
         itemMap.put("columnWidth", 50); 
         itemMap.put("dataKey", "XH4"); 
         headInfoList.add(itemMap); 
 
         List<Map<String, Object>> dataList = new ArrayList<Map<String,Object>>(); 
         Map<String, Object> dataItem = null; 
         for(int i=0; i < develpers.size(); i++){ 
         dataItem = new HashMap<String, Object>(); 
         Developer de=develpers.get(i);
         dataItem.put("XH1", ""+de.getAcctId()); 
         dataItem.put("XH2", ""+de.getUsername()); 
         dataItem.put("XH3", ""+de.getOpenId()); 
         dataItem.put("XH4", ""+de.getAcctRealNm()); 
         dataList.add(dataItem); 
         } 
         POIUtil.exportExcel2FilePath("統一認證平臺開發者資料資訊","D:\\temp\\customer2.xls", headInfoList, dataList); 
		

	}