我在尝试解析 JSON 数据时遇到 JSON 异常，我正在使用 Web 服务。
我已经查看了与此异常相关的相关问题，但我仍然无法提出解决方案。
这是来自网络服务的 Json 数组
[
{
"created_at":"2013-03-18T21:30:19Z",
"id":1,
"name":"latte",
"price":"5",
"updated_at":"2013-03-18T21:30:19Z"
},
{
"created_at":"2013-03-18T21:30:41Z",
"id":11,
"name":"black",
"price":"2",
"updated_at":"2013-03-18T21:30:41Z"
},
{
"created_at":"2013-03-19T09:38:31Z",
"id":21,
"name":"Tea",
"price":"2",
"updated_at":"2013-03-19T09:39:02Z"
}
]
这是使用解析器作为后台任务的类的相关部分
public class SpinnerDemo extends Activity {
//JSON node names
private static final String TAG_DATA = "data";
private static final String TAG_CREATED_AT = "created_at";
private static final String TAG_ID_DRINK = "id";
private static final String TAG_NAME = "name";
private static final String TAG_PRICE = "price";
private static final String TAG_UPDATED_AT = "updated_at";
private static final String MAP_API_URL = "http://notTheActualURL.com/drinks.json";
private BackGroundTask bgt;
Spinner drinkField;
ArrayList<Drink> drinkList = new ArrayList<Drink>();
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.spinner_main);
buildDrinkDropDown();
}
private void buildDrinkDropDown() {
List<NameValuePair> apiParams = new ArrayList<NameValuePair>(1);
apiParams.add(new BasicNameValuePair("call", "drinkList"));
bgt = new BackGroundTask(MAP_API_URL, "GET", apiParams);
try {
JSONObject drinkJSON = bgt.execute().get();
// Getting Array of drinks
JSONArray drinks = drinkJSON.getJSONArray(TAG_DATA);
// looping through All drinks
for (int i = 0; i < drinks.length(); i++) {
JSONObject d = drinks.getJSONObject(i);
// Storing each json item in variable
String id = d.getString(TAG_ID_DRINK);
String createdAt = d.getString(TAG_CREATED_AT);
String updatedAt = d.getString(TAG_UPDATED_AT);
String price = d.getString(TAG_PRICE);
String name = d.getString(TAG_NAME);
// add drink
drinkList.add(new Drink( createdAt ,id, name, price,updatedAt ));
}
这是进行解析的实际类
package com.android.main;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.os.AsyncTask;
import android.util.Log;
public class BackGroundTask extends AsyncTask<String, String, JSONObject> {
List<NameValuePair> postparams = new ArrayList<NameValuePair>();
String URL = null;
String method = null;
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
public BackGroundTask(String url, String method, List<NameValuePair> params) {
this.URL = url;
this.postparams = params;
this.method = method;
}
@Override
protected JSONObject doInBackground(String... params) {
// TODO Auto-generated method stub
// Making HTTP request
try {
// Making HTTP request
// check for request method
if (method.equals("POST")) {
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(URL);
httpPost.setEntity(new UrlEncodedFormEntity(postparams));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} else if (method == "GET") {
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils
.format(postparams, "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 {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data TEST " + e.toString());
}
// return JSON String
return jObj;
}
}
这是日志猫的异常
03-26 11:32:49.637: E/JSON Parser(714): Error parsing data TEST org.json.JSONException: Value [{"id":1,"created_at":"2013-03-18T21:30:19Z","updated_at":"2013-03-18T21:30:19Z","price":"5","name":"latte"},{"id":11,"created_at":"2013-03-18T21:30:41Z","updated_at":"2013-03-18T21:30:41Z","price":"2","name":"black"},{"id":21,"created_at":"2013-03-19T09:38:31Z","updated_at":"2013-03-19T09:39:02Z","price":"2","name":"Tea"}] of type org.json.JSONArray cannot be converted to JSONObject
另一个错误显示 spinnerDemo 类中的空点异常，尽管我认为这是先前异常的结果
03-26 11:32:49.707: E/AndroidRuntime(714): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.main/com.android.main.SpinnerDemo}: java.lang.NullPointerException
如有任何建议或帮助，我们将不胜感激
最佳答案
如日志中所示:
org.json.JSONArray cannot be converted to JSONObject
因为您正在获取 JSONArray 作为根元素而不是 JSONObject 但您正在尝试将其转换为 JSONObject。
目前您正在获取以下 json 结构:
[ //<<<<<<<<< JSONArray
{ //<<<<<<<<< JSONObject
},
....
]
您需要将 json 字符串转换为 JSONArray 然后从中提取 JSONObject
JSONArray drinkJSON = bgt.execute().get();
您还需要将 doInBackground 方法返回类型更改为 JSONArray
关于android - org.json.JSONArray 无法转换为 JSONObject(从 web 服务填充微调器)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15636410/