基于Struts2的Excel的下载

基于Struts2的Excel的下载，需要注意的问题比较多的，现在总结一下。

1、在struts.xml中需要配置下载设置
2、如果需要前端弹出下载框，则不能使用ajax提交，需要用form表单提交
3、 可用流返回

struts.xml

<result name="down" type="stream">  
                  
                <param name="contentType">application/vnd.ms-excelparam>  
                  
                <param name="inputName">excelStreamparam>  
                  
                <param name="contentDisposition">  
                    attachment;filename=${excelFileName}  
                param>  
                <param name="bufferSize">1024param>  
            result>   

ExportExcelAction.java

    private InputStream excelStream;  //输出流变量  
    private String excelFileName; //下载文件名  

    public InputStream getExcelStream() {  
        return excelStream;  
    }  
    public void setExcelStream(InputStream excelStream) {  
        this.excelStream = excelStream;  
    }  
    public String getExcelFileName() {  
        return excelFileName;  
    }  
    public void setExcelFileName(String excelFileName) {  
        this.excelFileName = excelFileName;  
    }  


    public String exportExcel() throws IOException{


        //创建一个HSSFWorkbook，对应一个Excel文件  
        HSSFWorkbook wb = new HSSFWorkbook();  

        ...

        //将文件存到流中  
        ByteArrayOutputStream os = new ByteArrayOutputStream();  
        wb.write(os);  
        byte[] fileContent = os.toByteArray();  
        ByteArrayInputStream is = new ByteArrayInputStream(fileContent);  
        excelStream = is;  //文件流  
        excelFileName = System.currentTimeMillis()+".xls"; //设置下载的文件名  
        return "down";  
    }