Question

我正在使用Android Volley库发送POST请求。对于POST请求

标题为Content-Type:application/json
帖子正文为Json String

但无论如何，我要更改Volley Request Header，它总是设置为Content-Type:text/html。这给了我400 Bad Request。这是我在POST

上执行Volley请求的课程

public class GsonRequest<T> extends Request<T> {
private final Class<T> clazz;
private final Map<String, String> headers;
private final Listener<T> listener;
private Map<String, String> postParams;
private String postString = null;

/**
 * Make a GET request and return a parsed object from JSON.
 * 
 * @param url
 *            URL of the request to make
 * @param clazz
 *            Relevant class object, for Gson's reflection
 * @param headers
 *            Map of request headers
 */
public GsonRequest(int method, String url, Class<T> clazz,
        Map<String, String> headers, Map<String, Object> params,
        Listener<T> listener, ErrorListener errorListener) {
    super(method, url, errorListener);

    this.clazz = clazz;
    this.headers = headers;
    this.listener = listener;

    if (method == Method.POST && params != null && params.size() > 0) {
        setRetryPolicy(new DefaultRetryPolicy(12000, 0,
                DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
        postString = new GsonBuilder().create().toJson(params);
    }

}

@Override
public Map<String, String> getHeaders() throws AuthFailureError {
    return headers != null ? headers : super.getHeaders();

}

@Override
public byte[] getBody() throws AuthFailureError {

    return postString != null ? postString.getBytes(Charset
            .forName("UTF-8")) : super.getBody();
}

@Override
public String getBodyContentType() {
    return postString !=null?"application/json; charset=utf-8":super.getBodyContentType();
}

@Override
protected void deliverResponse(T response) {
    listener.onResponse(response);
}

@Override
protected Response<T> parseNetworkResponse(NetworkResponse response) {
    try {
        String json = new String(response.data,
                HttpHeaderParser.parseCharset(response.headers));
        Log.i("response", json);

        T responses = new GsonBuilder().create().fromJson(json, clazz);
        return Response.success(responses,
                HttpHeaderParser.parseCacheHeaders(response));
    } catch (UnsupportedEncodingException e) {
        return Response.error(new ParseError(e));
    } catch (JsonSyntaxException e) {
        return Response.error(new ParseError(e));
    } catch (Exception e) {
        return Response.error(new ParseError(e));

    }
}
}

我知道我做错了什么。我已经使用普通HttpPost进行了测试，并且可以从那里开始工作，但在使用Volley时，我的POST Header永远不会改变。

Answer 1

我发现我必须覆盖getBodyContentType()才能让Content-Type标头正确更新：

    public String getBodyContentType()
    {
        return "application/json; charset=utf-8";
    }

以下是关于此问题的更多详细信息的问题：

Volley Content-Type header not updating

Answer 2

使用Wireshark之类的网络嗅探工具，我发现我的错误位于错误的HTTP header上。然后使用Chrome DHC plugin

我发现Header Content-Type应为application/json; charset=utf-8而且我一直在使用

    Map<String, String> header = new HashMap<String, String>();
    header.put("Content-Type", "application/json");

而不是

    Map<String, String> header = new HashMap<String, String>();
    header.put("Content-Type", "application/json; charset=utf-8");

使用正确的Header解决了我的问题

Android Volley Post Request标题不变

2 个答案: