JSONException：字符 0 处的输入结束

Question

我正在尝试从服务器获取 JSON 值。我不知道我的代码有什么问题。我正在使用AsyncTask，这是我在doInBackground中的代码

代码：

@Override
    protected Void doInBackground(List<String>... articlesRec) {
        for (List<String> articlesPostValue : articlesRec) {
            event = articlesPostValue.get(0);
            category = articlesPostValue.get(1);
            paged = articlesPostValue.get(2);
            deviceID = articlesPostValue.get(3);
        }

        List<NameValuePair> articlesPostValues = new ArrayList<NameValuePair>();
        articlesPostValues.add(new BasicNameValuePair("_event", event));
        articlesPostValues.add(new BasicNameValuePair("cat", category));
        articlesPostValues.add(new BasicNameValuePair("paged", paged));
        articlesPostValues.add(new BasicNameValuePair("_deviceID", deviceID));

        HttpClient hc = new DefaultHttpClient();
        HttpPost hp = new HttpPost(AutoLifeConstants.BASE_URL);

        try {
            hp.setEntity(new UrlEncodedFormEntity(articlesPostValues));

            // Execute HTTP Post Request
            HttpResponse response = hc.execute(hp);

            String result = EntityUtils.toString(response.getEntity());
            String jsontext = new String(result);

            JSONObject entries = new JSONObject(jsontext);

            this.response = entries.getString("response_code");

            try {
                String totalPageStr = entries.getString("total_pages");
                totalPage = Integer.valueOf(totalPageStr);
            } catch (Exception e) {

            }

            JSONArray postListArray = entries.getJSONArray("posts_list");

            for (int i = 0; i < postListArray.length(); i++) {
                JSONObject postListObj = postListArray.getJSONObject(i);

                String articlesTitle = postListObj.getString("title");
                String dateTime = postListObj.getString("date");
                String articlesImage = postListObj.getString("feature_image");
                String descrition = postListObj.getString("content");
                String fullDescription = postListObj.getString("full_content");

                articlesNewesttitle.add(articlesTitle);
                articlesNewestPostTime.add(dateTime);
                articlesNewestPostImage.add(articlesImage);
                articlesNewestPostDescription.add(descrition);
                postFullDescription.add(fullDescription);

                Log.d("Title",articlesTitle);
            }

        } catch (Exception e) {
            Log.e("catched error","Exceptin occured");
            e.printStackTrace();
        }

        return null;
    }

这里是 logcat 上的catch(Exception e)

    06-19 13:22:32.229: W/System.err(19647): org.json.JSONException: End of input at character 0 of 
06-19 13:22:32.264: W/System.err(19647):    at org.json.JSONTokener.syntaxError(JSONTokener.java:450)
06-19 13:22:32.265: W/System.err(19647):    at org.json.JSONTokener.nextValue(JSONTokener.java:97)
06-19 13:22:32.268: W/System.err(19647):    at org.json.JSONObject.<init>(JSONObject.java:154)
06-19 13:22:32.269: W/System.err(19647):    at org.json.JSONObject.<init>(JSONObject.java:171)
06-19 13:22:32.270: W/System.err(19647):    at np.com.autolife.adapters.NewsActivity$Get_postlist.doInBackground(NewsActivity.java:169)
06-19 13:22:32.272: W/System.err(19647):    at np.com.autolife.adapters.NewsActivity$Get_postlist.doInBackground(NewsActivity.java:1)
06-19 13:22:32.272: W/System.err(19647):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
06-19 13:22:32.273: W/System.err(19647):    at java.util.concurrent.FutureTask.run(FutureTask.java:234)
06-19 13:22:32.273: W/System.err(19647):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
06-19 13:22:32.274: W/System.err(19647):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
06-19 13:22:32.274: W/System.err(19647):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
06-19 13:22:32.281: W/System.err(19647):    at java.lang.Thread.run(Thread.java:838)

这里是JSON格式

    {
    "get": [],
    "post": {
        "_event": "get_posts",
        "_deviceID": "490154203237518",
        "cat": "2",
        "paged": "1"
    },
    "response_code": "success",
    "posts_total": 8,
    "total_pages": 2,
    "paged": 1,
    "posts_list": [
        {
            "ID": 9168,
            "title": "MAXXIS Introduce Trepador Tires",
            "content": "",
            "full_content": "http:xxxxxx",
            "date": "June 13, 2014",
            "category": "All News & Events, Local News",
            "feature_image": "http:xxxxx.jpg",
            "feature_image_thumb": "http:xxxx.jpg",
            "author": "AutoLife Team"
        },
        {
            "ID": 9162,
            "title": "5 Year Warranty On All Hero Motorcycles",
            "content": "",
            "full_content": "http://xxxxx",
            "date": "June 13, 2014",
            "category": "All News & Events, Local News",
            "feature_image": "http://xxxxxx.jpg",
            "feature_image_thumb": "http://xxxx.jpg",
            "author": "AutoLife Team"
        },
        {
            "ID": 8130,
            "title": "All new 11th Generation Toyota Corolla Launched",
            "content": "",
            "full_content": "http://xxxxxx",
            "date": "May 1, 2014",
            "category": "Events & Schemes",
            "feature_image": "http://xxxxxx.png",
            "feature_image_thumb": "http://xxxxxx.png",
            "author": "supervisor"
        },
        {
            "ID": 9178,
            "title": "New Launches From TATA Motors : TATA Nano Twist",
            "content": "",
            "full_content": "http://xxxxxx",
            "date": "February 15, 2014",
            "category": "All News & Events, International News",
            "feature_image": "http://xxxxx.jpg",
            "feature_image_thumb": "xxxxxxx.jpg",
            "author": "AutoLife Team"
        },
        {
            "ID": 9175,
            "title": "New Launches From TATA Motors : Revotron Engine",
            "content": "",
            "full_content": "xxxxxxx",
            "date": "February 15, 2014",
            "category": "All News & Events, International News",
            "feature_image": "http://xxxxx.jpg",
            "feature_image_thumb": "http://xxxxx.jpg",
            "author": "AutoLife Team"
        }
    ]
}

Answer 1

您收到此错误的原因是您尝试多次访问响应。例如，假设您对响应进行日志记录，然后使用相同的响应对象创建一个 json 对象，它会触发一次 acees 错误。

Answer 2

您可能会收到空白回复。它不为空，但 jsontext 为空。所以你得到这个错误而不是 Nullpointer 异常

您是否向服务器发送了正确的参数。还要检查 url 是否响应 POST 请求。

Answer 3

在处理 JSON 之前检查响应是否为空：

if (response.success()) {
    if (response.getData() == null) {
        return null;
    } else if (response.getData().length() <= 0){
        return null;
    }

    try {
        // Logic