ireport导出excel乱码,该怎么解决

public String branchExcelReport(List list) {
		JasperPrint jasperPrintArr=null;
		ArrayList jasperPrintList = new ArrayList();
		HttpServletResponse resp=null;
		JasperReport report;
    	Map map=new HashMap();
    	String realPath = "";
		resp = (HttpServletResponse)ActionContext.getContext().get(org.apache.struts2.StrutsStatics.HTTP_RESPONSE);
    	realPath =ServletActionContext.getServletContext().getRealPath(
				"/report/template/Branch.jasper");
 
    	JRDataSource dataSource = new JRBeanCollectionDataSource(list);
    	try {
			report = (JasperReport)JRLoader.loadObject(realPath);
		
    	jasperPrintArr = JasperFillManager.fillReport (report,  map, dataSource);  
    	jasperPrintList.add(jasperPrintArr);
    	
        //设定输出格式
        FileBufferedOutputStream fbos = new FileBufferedOutputStream(); 
        // 使用JRPdfExproter导出器导出pdf  
        JRPdfExporter exporter = new JRPdfExporter();  
        // 设置JasperPrintList  
        exporter.setParameter(JRExporterParameter.JASPER_PRINT_LIST, jasperPrintList);  
        exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, fbos);   
        exporter.setParameter(JRXlsExporterParameter.IS_REMOVE_EMPTY_SPACE_BETWEEN_ROWS, Boolean.TRUE); 
        exporter.setParameter(JRXlsExporterParameter.IS_ONE_PAGE_PER_SHEET, Boolean.FALSE); 
        exporter.setParameter(JRXlsExporterParameter.IS_WHITE_PAGE_BACKGROUND, Boolean.FALSE);
        exporter.exportReport();   
        	resp.reset();   
        	resp.setContentType("application/vnd.ms-excel;charset=UTF-8");   
        	resp.setCharacterEncoding("UTF-8");
        	resp.setContentLength(fbos.size()); 
        	resp.setHeader("Content-Disposition", "attachment; filename=BRANCH.xls");
            ServletOutputStream ouputStream = resp.getOutputStream(); 
            

            try
            { 
                fbos.writeData(ouputStream); 
                fbos.dispose(); 
                ouputStream.flush(); 
            } 
            finally