Question

我正在为我的Android手机构建一个小应用程序，使用非常基本的REST界面将文本消息转发到Web服务器。

我正在使用android 4.0.3 SDK。我使用Django和Django restframework包在python中开发了webservice。设置完全开箱即用。基本上有一个端点接收包含消息信息（发送者，正文，日期）的JSON对象的POST。我使用cURL使用以下命令测试了服务：

curl -X POST -H 'Content-Type: application/json' --data '{"sender":"+xxxxxxxx", "body": "test", "send_date":"2011-03-20 16:32:02"}' http://[...]/messages.json

这一切都很好，我得到了预期的回应：

{"body": "test", "send_date": "2011-03-20T16:32:02", "id": 25, "sender": "+xxxxxxxxxx"}

现在我设置了Android应用程序。它是一个简单的BroadcastReceiver子类，包含一个私有的AsyncTask类：

private class httpPost extends AsyncTask<String, Void, JSONObject> {
    protected JSONObject doInBackground(String... args) {
        // Create a new HttpClient and Post Header
        HttpClient httpclient = new DefaultHttpClient();
        HttpParams myParams = new BasicHttpParams();
        HttpConnectionParams.setConnectionTimeout(myParams, 10000);
        HttpConnectionParams.setSoTimeout(myParams, 10000);

        String url = args[0];
        String json=args[1];            
        JSONObject JSONResponse = null;
        InputStream contentStream = null;
        String resultString = "";

        try {
            HttpPost httppost = new HttpPost(url);
            httppost.setHeader("Content-Type", "application/json");
            httppost.setHeader("Accept", "application/json");

            StringEntity se = new StringEntity(json); 
            se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
            httppost.setEntity(se);

            for (int i=0;i<httppost.getAllHeaders().length;i++) {
                Log.v("set header", httppost.getAllHeaders()[i].getValue());
            }

            HttpResponse response = httpclient.execute(httppost);

            // Do some checks to make sure that the request was processed properly
            Header[] headers = response.getAllHeaders();
            HttpEntity entity = response.getEntity();
            contentStream = entity.getContent();

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        //convert response to string
        try{
            BufferedReader reader = new BufferedReader(new InputStreamReader(contentStream,"iso-8859-1"),8);
            StringBuilder sb = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            contentStream.close();
            resultString = sb.toString();
        }catch(Exception e){
            e.printStackTrace();
        }

        Log.v("log", resultString);
        return new JSONObject();
    }


}

正如您所看到的，我刚刚开始熟悉Java和Android SDK，所以请耐心等待。这个设置实际上在我构建的另一个应用程序中运行良好，可以将JSON字符串发送到Neo4J Web服务。

问题在于，当我通过Android将消息发布到我的webservice时，在某些时候内容类型从'application / json'变为'application / json，application / json'。 header循环中的日志条目仍然为每个标头输出正确的值，但是，webservice返回此错误消息：

{"error": "Unsupported media type in request 'application/json, application/json'."}

我很困惑，欢迎任何帮助。

Answer 1

改变这个：

StringEntity se = new StringEntity(json); 
se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
httppost.setEntity(se);

仅限于此：

httppost.setEntity(new StringEntity(json.toString(), HTTP.UTF_8));

Answer 2

简单：

import org.apache.http.client.methods.HttpPost;

httppost.setEntity(new StringEntity(json.toString(), org.apache.http.entity.ContentType.APPLICATION_JSON));

Java HttpClient改变内容类型？

2 个答案: