java - 从请求中读取时防止 IllegalStateException

Question

我有一个拦截器用于捕获异常并发送有关此异常的电子邮件。

我所有的 struts 操作都扩展了实现 SerlvetRequestAware 的 CoreController。

在邮件服务类中，我有:

CoreController cc = (CoreController)invocation.getAction();
HttpServletRequest request = cc.getRequest();

我想将请求正文插入电子邮件(如果存在)。像这样:

StringWriter msg = new StringWriter();
msg.write("Requested URI: " + request.getRequestURI()+NEW_LINE);
msg.write("Requested Query String: " + request.getQueryString()+NEW_LINE);
msg.write("Request method: "+request.getMethod()+NEW_LINE);
try {
 if (request.getReader() != null) {
  msg.write("Request body: "+ request.getReader().readLine()+NEW_LINE);
  request.getReader().close();
 }
} catch (IOException e) {
    e.printStrackTrace();
} catch(IllegalStateException e) {
    e.printStrackTrace();
}

现在，当 reader 不为空时，它总是抛出 IllegalStateException。我如何“还原”阅读器或如何以任何其他方式阅读请求正文？

编辑异常:已经为此请求调用了 getInputStream()

Answer 1

如果您收到 IllegalStateException，也许您应该尝试使用请求的 InputStream 而不是它的 Reader:

BufferedReader bufferedReader;
try {
    bufferedReader = request.getReader();
} catch (IllegalStateException e) {
    InputStream inputStream = request.getInputStream();

    // As per BalusC's comment:
    String charsetName = request.getCharacterEncoding();
    if (charsetName == null) {
        charsetName = "UTF-8";
    }

    InputStreamReader inputStreamReader = new InputStreamReader(inputStream, charsetName);
    bufferedReader = new BufferedReader(inputStreamReader);
}

bufferedReader.readLine();