Servlet 怎么样才能得到完整的 Http 请求输入流

象这样只能得到请求体，不能获取到包括头部的整个二进制数据

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        OutputStreamWriter osw = new OutputStreamWriter(resp.getOutputStream());
	    InputStream is = req.getInputStream();
        osw.write(Constant.TEST_WEBSOCKET_PAGE);
        osw.flush();
    }

处理 Http 是 Web 容器的工作，AJP 将数据传给 Servlet 就已经是解析过的对象，因此不能直接获取到原本的内容

自己再拼接回去咯 😆

GET http://www.ruanyifeng.com/static/themes/theme_scrapbook/theme_scrapbook.css HTTP/1.1
Host: www.ruanyifeng.com
Connection: keep-alive
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36
Accept: text/css,*/*;q=0.1
Referer: http://www.ruanyifeng.com/blog/2016/08/http.html
Accept-Encoding: gzip, deflate, sdch
Accept-Language: zh-CN,zh;q=0.8
Cookie: _ga=GA1.2.1640937992.1474458063

    public static final byte[] PROTOCOL_BYTES = " HTTP/1.1\r\n".getBytes();
    public static final byte[] CRLF_BYTES = "\r\n".getBytes();
    public static final byte BLANK_BYTE = ' ';
    public static final byte[] COLON_BYTES = ": ".getBytes();
    public static final byte QUESTION_BYTE = '?';
	
    public byte[] getRequestRaw(HttpServletRequest req) throws IOException {
        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
        // header values
        bufferWriteBytesFromStringAllowNull(buffer, req.getMethod());
        buffer.write(BLANK_BYTE);
        bufferWriteBytesFromStringAllowNull(buffer, req.getRequestURL().toString());
        buffer.write(QUESTION_BYTE);
        bufferWriteBytesFromStringAllowNull(buffer, req.getQueryString());
        buffer.write(PROTOCOL_BYTES);
        Enumeration<String> headerNames = req.getHeaderNames();
        while (headerNames.hasMoreElements()) {
            String headerName = headerNames.nextElement();
            String headerValue = req.getHeader(headerName);
            buffer.write(headerName.getBytes());
            buffer.write(COLON_BYTES);
            bufferWriteBytesFromStringAllowNull(buffer, headerValue);
            buffer.write(CRLF_BYTES);
        }
        buffer.write(CRLF_BYTES);
        // body values
        InputStream inputStream = req.getInputStream();
        int nRead;
        byte[] data = new byte[1024];
        while ((nRead = inputStream.read(data, 0, data.length)) != -1) {
            buffer.write(data, 0, nRead);
        }
        buffer.flush();
        byte[] byteArray = buffer.toByteArray();
        return byteArray;
    }

    public String getRequestBase64(HttpServletRequest req) throws IOException {
        byte[] rawBytes = getRequestRaw(req);
        return Base64.getEncoder().encodeToString(rawBytes);
    }

    public String encodeBase64BytesString(String base64Bytes) {
        byte[] bytes = Base64.getDecoder().decode(base64Bytes);
        StringBuffer stringBuffer = new StringBuffer();
        for (byte b : bytes) {
            stringBuffer.append((char) b);
        }
        return stringBuffer.toString();
    }

    public void bufferWriteBytesFromStringAllowNull(ByteArrayOutputStream byteArrayOutputStream, String string) throws IOException {
        if (string != null) {
            if (string.getBytes() != null) {
                byteArrayOutputStream.write(string.getBytes());
            }
        }
    }

那个 ByteArrayOutputStream 应该可以共用，需要吧所有的数据都给转到 byte[]

问一下那个 bufferWriteBytesFromStringAllowNull 应该是是不是写成继承扩展比较好，而不是调用自身

消息同步不会写，想想还是算了。。。