http设置的响应用消息

/**
     * 不带消息体的响应方法
     * 
     * @param code 响应码
     * @param request TODO
     * @param response
     * @throws IOException 当响应输出异常时抛出
     */
    public static void response(int code, HttpServletRequest request, HttpServletResponse response)
        throws IOException
    {
        // 必选
        response.setHeader(APIVERSION_KEY, apiVersion);
        response.setHeader(TIMESTAMP_KEY, sf.format(new Date()));
        
        response.setHeader(RESULT_CODE_KEY, String.valueOf(code));
        
        // add by c59623 为了便于记录系统错误话单，需要在request设置错误码，以便在过滤器能识辨
        request.setAttribute(RESULT_CODE_KEY, String.valueOf(code));
    }
    
    /**
     * 处理带消息内容处理。包括设置返回参数返回消息内容
     * 
     * @param xml 响应消息内容
     * @param request http请求
     * @param response http响应
     * @throws IOException 当响应输出异常时抛出
     * 
     */
    public static void response(String xml, HttpServletRequest request, HttpServletResponse response)
        throws IOException
    {
        String code = (String)request.getAttribute("resultCode");
        if (null == code || "".equals(code))
        {
            code = String.valueOf(TerminalCodes.SUCCESS);
        }
        
        int resultCode = StringTools.toInt(code, TerminalCodes.SUCCESS);
        
        // 默认返回
        response(resultCode, request, response);
        
        /*
         * 以下为消息体返回处理
         */

        ByteArrayOutputStream baseOut = new ByteArrayOutputStream(512);
        
        // 默认输出到ByteArrayOutputStream中
        OutputStream out = baseOut;
        
        String acceptEncoding = StrUtil.trim(request.getHeader(ACCEPT_ENCODING_KEY));
        if (GZIP.equalsIgnoreCase(acceptEncoding))
        {
            // 内容压缩类型
            response.setHeader(CONTENT_ENCODING_KEY, acceptEncoding);
            
            // 支持gzip压缩时压缩流也输出到ByteArrayOutputStream中
            out = new GZIPOutputStream(baseOut);
        }
        
        byte[] xmlHead = XMLHEAD.getBytes(UTF8);
        byte[] start = START.getBytes(UTF8);
        byte[] xmlBytes = xml.getBytes(UTF8);
        byte[] end = END.getBytes(UTF8);
        
        int origSize = xmlHead.length + start.length + xmlBytes.length + end.length;
        
        out.write(xmlHead);
        out.write(start);
        out.write(xmlBytes);
        out.write(end);
        
        // 关闭流，确保所有输出都结束
        out.close();
        
        // 必选：消息内容长度
        response.setHeader(CONTENT_LENGTH_KEY, String.valueOf(baseOut.size()));
        response.setHeader(ORIG_CONTENT_LENGTH_KEY, String.valueOf(origSize));
        
        // 可选
        response.setCharacterEncoding(UTF8);
        response.setHeader(CONTENT_TYPE_KEY, "application/xml");
        
        // 返回消息内容
        baseOut.writeTo(response.getOutputStream());
    }