微信公众号验证成为开发者配置失败问题

开发语言java

微信开发文档要求：开发者通过检验signature对请求进行校验（下面有校验方式）。若确认此次GET请求来自微信服务器，请原样返回echostr参数内容，则接入生效，成为开发者成功，否则接入失败。

然而直接return echostr出去一直提示配置失败

最后，将return echostr；改成下面：

responseUtil(response, echostr);

private void responseUtil(HttpServletResponse response, String value){
    try {
        PrintWriter pw = response.getWriter();
        pw.write(value);
        pw.flush();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

结果提示配置成功！

完整代码如下：

@SuppressWarnings({ "rawtypes" })
@ApiResponses(value = {@ApiResponse(code = 200, message = "请求成功")})
@ApiOperation(value = "微信公众号信号接口", notes = "微信公众号信号接口", response = String.class)
@ResponseBody
@RequestMapping(value = "/checkSignature", method = {RequestMethod.GET})
public String checkSignature(@ApiParam(value = "signature") @RequestParam() String signature,
                             @ApiParam(value = "timestamp") @RequestParam() String timestamp,
                             @ApiParam(value = "nonce") @RequestParam() String nonce,
                             @ApiParam(value = "echostr") @RequestParam() String echostr,
                             HttpServletResponse response) {
    logger.info("微信公众号信号接口");

    try {
        String[] strings = new String[]{CfgKey.WX_OFFICIAL_TOKEN, timestamp, nonce};
        StringBuilder builder = new StringBuilder();
        Arrays.sort(strings);

        for(String string : strings) {
            builder.append(string);
        }

        //sha1
        String res = sha1(builder.toString())      
        logger.info("加密后："+res);
        if(signature.equalsIgnoreCase(res)){
            logger.info("成功 --> signature: " + signature);
            responseUtil(response, echostr);
        }

        logger.info("失败");
        return "";
    } catch (Exception e) {
        e.printStackTrace();
        return "";
    }
}