我有这个例外
Value of type java.lang.String cannot be converted to JSONArray
尝试解析JSON时。
JSONParser.java
public class JSONParser {
static InputStream is = null;
static JSONArray jArray = null;
static String json = "";
// constructor
public JSONParser() {
}
// function get json from url
// by making HTTP POST or GET mehtod
public JSONArray makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
// check for request method
if(method == "POST"){
// request method is POST
// defaultHttpClient
System.out.println("in post, url: "+url);
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
System.out.println("in get, url: "+url);
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"UTF-8"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jArray = new JSONArray(json);
System.out.println("jArray: "+jArray);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jArray;
}
}
NewsActivity.java
public class NewsActivity extends Activity {
ListView newsListView;
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jsonParser = new JSONParser();
ArrayList<HashMap<String, String>> newsList;
// products JSONArray
JSONArray News = null;
NewsAdapter newAdapter;
ImageButton home;
// News JSON url
// http://www.giga-soft.com/fredericm_mobile
private static final String NEWS_URL = "my_URL.php";
// ALL JSON node names
static final String NEWS_ID = "news_id";
static final String NEWS_CONTENT = "news_content";
static final String NEWS_PHOTO = "news_photo";
static final String NEWS_PHOTO_THUMB = "news_photo_thumb";
static final String NEWS_CREATED_DATE = "news_created_date";
static final String NEWS_ORD = "news_ord";
static final String NEWS_STATE = "news_state";
static final String NEWS_LAST_UPDATE = "news_last-update";
static final String NEWS_TITLE = "news_title";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.news_list);
newsListView = (ListView)findViewById(R.id.news_list);
newsListView.setItemsCanFocus(true);
// Hashmap for ListView
newsList = new ArrayList<HashMap<String, String>>();
home = (ImageButton) findViewById(R.id.TitleHomeBtn);
home.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent(NewsActivity.this, MainActivity.class);
startActivity(intent);
}
});
// Loading News in Background Thread
new LoadNews().execute();
}
/**
* Background Async Task to Load all News messages by making HTTP Request
* */
class LoadNews extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(NewsActivity.this);
pDialog.setMessage(getResources().getString(R.string.loadNews));
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting News JSON
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONArray jsonArray = jsonParser.makeHttpRequest(NEWS_URL, "GET", params);
///////////////// the following line gives Exception /////////////////////
System.out.println("jsonArray.length(): "+jsonArray.length());
JSONObject jsonObject = null;
// Check your log cat for JSON reponse
Log.d("News JSON: ", jsonArray.toString());
try {
// looping through All messages
for (int i = 0; i < jsonArray.length(); i++) {
jsonObject = jsonArray.getJSONObject(i);
System.out.println("jsonObject: "+jsonObject);
// Storing each json item in variable
String news_id = jsonObject.getString(NEWS_ID);
String news_content = jsonObject.getString(NEWS_CONTENT);
String news_photo = jsonObject.getString(NEWS_PHOTO);
String news_photo_thumb = jsonObject.getString(NEWS_PHOTO_THUMB);
String news_created_date = jsonObject.getString(NEWS_CREATED_DATE);
String news_ord = jsonObject.getString(NEWS_ORD);
String news_state = jsonObject.getString(NEWS_STATE);
String news_last_update = jsonObject.getString(NEWS_LAST_UPDATE);
String news_title = jsonObject.getString(NEWS_TITLE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(NEWS_ID, news_id);
map.put(NEWS_CONTENT, news_content);
map.put(NEWS_PHOTO, news_photo);
map.put(NEWS_PHOTO_THUMB, news_photo_thumb);
map.put(NEWS_CREATED_DATE, news_created_date);
map.put(NEWS_ORD, news_ord);
map.put(NEWS_STATE, news_state);
map.put(NEWS_LAST_UPDATE, news_last_update);
map.put(NEWS_TITLE, news_title);
// adding HashList to ArrayList
newsList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
newAdapter = new NewsAdapter(NewsActivity.this, newsList);
// updating listview
newsListView.setAdapter(newAdapter);
}
});
}
}
}
：
<?php
include ('config.php');
mysql_query('SET CHARACTER SET UTF8');
mysql_query("SET NAMES utf8; ");
$check = mysql_query("SELECT * FROM news WHERE 1");
while($row=mysql_fetch_assoc($check))
$output[]=$row;
$json_encode =json_encode($output);
$utf8_decode = utf8_decode($json_encode);
echo $json_encode;
mb_convert_encoding($json_encode, 'UTF-8');
$html_entity_decode = html_entity_decode($json_encode);
mysql_close();
php代码：
?[
{
"news_id": "11",
"news_content": "\u0639\u0637\u0648\u0631 \u0628\u0623\u062e\u0641 \u0627\u0644\u0627\u062d\u062c\u0627\u0645 \u062a\u0635\u0644\u062d \u0644\u062c\u0645\u064a\u0639 \u0627\u0644\u0627\u0633\u062a\u0639\u0645\u0627\u0644\u0627\u062a \u0627\u0644\u064a\u0648\u0645\u064a\u0629.. \u0648\u062a\u0624\u062e\u0630 \u0627\u0644\u0649 \u0627\u064a \u0645\u0643\u0627\u0646 \u0648\u062a\u0648\u0636\u0639 \u0641\u064a \u0627\u064a \u0645\u0643\u0627\u0646 \u0628\u0633\u0647\u0648\u0644\u0629 .. \u0628\u0627\u0644\u0627\u0636\u0627\u0641\u0629 \u0627\u0644\u0649 \u0639\u0637\u0631\u0647\u0627 \u0627\u0644\u062e\u0644\u0627\u0628",
"news_photo": "http:\/\/www.abarid.com\/Mobile_apps\/products_thumb\/Untitled6.png",
"news_photo_thumb": "",
"news_internal_photo": "http:\/\/www.abarid.com\/Mobile_apps\/products_thumb\/Untitled6.png",
"news_photo_internal_thumb": "",
"news_created_date": "2013-10-31",
"news_ord": "1",
"news_state": "1",
"news_last-update": "2013-11-13 23:20:39",
"news_title": "Pocket Perfums"
},
{
"news_id": "12",
"news_content": "\u0627\u0644\u0637\u0628\u064a\u0639\u0629 \u062f\u0627\u0626\u0645\u0627 \u0627\u0641\u0636\u0644.. \u0645\u0645\u064a\u0632\u0627\u062a \u0627\u0644\u0645\u0643\u064a\u0627\u062c \u0627\u0644\u0645\u0639\u062f\u0646\u0649\n\u0628\u0648\u062f\u0631\u0629 \u062f\u0642\u064a\u0642\u0629 \u0644\u0627 \u062a\u0633\u062f \u0645\u0633\u0627\u0645 \u0627\u0644\u062c\u0644\u062f \u0648 \u062a\u0633\u0627\u0639\u062f \u0627\u0644\u062c\u0644\u062f \u0639\u0644\u0649 \u0627\u0644\u062a\u0646\u0641\u0633\n\u0645\u062b\u0627\u0644\u064a\u0629 \u0644\u0644\u062c\u0644\u062f \u0627\u0644\u062d\u0633\u0627\u0633 \u0627\u0648 \u0627\u0644\u0645\u062a\u0636\u0631\u0631 - \u0645\u0627\u0646\u0639 \u0637\u0628\u064a\u0639\u0649 \u0636\u062f \u0627\u0634\u0639\u0629 \u0627\u0644\u0634\u0645\u0633 \u0627\u0644\u0636\u0627\u0631\u0629",
"news_photo": "http:\/\/www.abarid.com\/Mobile_apps\/products_thumb\/Untitled8.png",
"news_photo_thumb": "",
"news_internal_photo": "http:\/\/www.abarid.com\/Mobile_apps\/products_thumb\/Untitled8.png",
"news_photo_internal_thumb": "",
"news_created_date": "2013-10-31",
"news_ord": "2",
"news_state": "1",
"news_last-update": "2013-11-13 23:20:45",
"news_title": "\u0627\u0644\u0645\u0643\u064a\u0627\u062c \u0627\u0644\u0645\u0639\u062f\u0646\u064a"
},
{
"news_id": "13",
"news_content": "\u0644\u0627\u0637\u0644\u0627\u0644\u0629 \u0645\u062a\u0645\u064a\u0632\u0629 \u0648\u0627\u0646\u064a\u0642\u0629 \u062a\u062a\u0645\u064a\u0632 \u0628\u0631\u0642\u0629 \u0627\u0644\u062a\u0635\u0645\u064a\u0645 ",
"news_photo": "http:\/\/www.abarid.com\/Mobile_apps\/products_thumb\/Untitled9.jpeg",
"news_photo_thumb": "http:\/\/www.abarid.com\/Mobile_apps\/products_thumb\/Untitled9.jpeg",
"news_internal_photo": "",
"news_photo_internal_thumb": "",
"news_created_date": "2013-12-30",
"news_ord": "3",
"news_state": "1",
"news_last-update": "2014-02-21 01:47:15",
"news_title": "\u0633\u0648\u0627\u0631 \u0627\u0644\u0631\u062c\u0644 \u0627\u0644\u0645\u062a\u0645\u064a\u0632"
},
{
"news_id": "14",
"news_content": "\u0639\u0631\u0636 \u0631\u0627\u0626\u0639 \u0645\u0646 \u0641\u0631\u064a\u062f\u0631\u064a\u0643 \u0627\u0645",
"news_photo": "http:\/\/www.giga-soft.com\/fredericm\/uploads\/152488.png?r=169902398",
"news_photo_thumb": "http:\/\/www.giga-soft.com\/fredericm\/uploads\/152488_thumb.png?r=169902398",
"news_internal_photo": "",
"news_photo_internal_thumb": "",
"news_created_date": "2013-12-31",
"news_ord": "4",
"news_state": "1",
"news_last-update": "2013-12-31 17:09:10",
"news_title": "\u0627\u0633\u0648\u0631\u0629 \u0642\u0644\u0628 \u0627\u0644\u064a\u0627\u0642\u0648\u062a"
}
]
导致异常以及如何解决的错误是什么？ 希望有人能帮助我。
答案 0 :(得分：0)
您是否检查了传递给JSONArray的值，是否符合您的预期？ 您的问题可能与Value of type java.lang.String cannot be converted to JSONArray
重复答案 1 :(得分：0)
您应该向HttpPost添加setContent("application/json")以确保它将接收JSON对象。
请参阅documentation。
答案 2 :(得分：0)
public class JSONParser {
static String response = null;
public final static int GET = 1;
public final static int POST = 2;
public ServiceHandler() {
}
/**
* Making service call
* @url - url to make request
* @method - http request method
* */
public String makeServiceCall(String url, int method) {
return this.makeServiceCall(url, method, null);
}
/**
* Making service call
* @url - url to make request
* @method - http request method
* @params - http request params
* */
public String makeServiceCall(String url, int method,
List<NameValuePair> params) {
try {
// http client
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpEntity httpEntity = null;
HttpResponse httpResponse = null;
// Checking http request method type
if (method == POST) {
HttpPost httpPost = new HttpPost(url);
// adding post params
if (params != null) {
httpPost.setEntity(new UrlEncodedFormEntity(params));
}
httpResponse = httpClient.execute(httpPost);
} else if (method == GET) {
// appending params to url
if (params != null) {
String paramString = URLEncodedUtils
.format(params, "utf-8");
url += "?" + paramString;
}
HttpGet httpGet = new HttpGet(url);
httpResponse = httpClient.execute(httpGet);
}
System.out.println("Status in url =====" + httpResponse.getStatusLine().getStatusCode());
httpEntity = httpResponse.getEntity();
response = EntityUtils.toString(httpEntity);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return response;
}
}