jsp 导出文件实例代码

public ActionForward exportFile(ActionMapping mapping, ActionForm form, HttpServletRequest request,
            HttpServletResponse response) throws Exception {
        String natLog = "test";
                
        try {
            StringBuilder fileName = null;
            OutputStream output = null;
            
            byte[] streamBytes = natLog.getBytes();
            if (streamBytes == null) {

            } else {
                fileName = new StringBuilder(64);
                fileName.append("export.txt");
                try {