那里。我是一名开始学习构建Android应用程序的学生......
我的代码在这里遇到了困难......
我读了很多页面如何解决问题，我还没有找到它......或者我可能不理解。 HAHAH
logcat总是这样：
03-10 11:12:43.057: D/dalvikvm(636): GC_EXTERNAL_ALLOC freed 1001 objects / 69352 bytes in 99ms
03-10 11:12:46.458: E/JSON Parser(636): Error parsing data org.json.JSONException: Names must be strings, but [{"pass_mobile":"affanganteng","user_mobile":"affan"},{"pass_mobile":"affandroid1","user_mobile":"affandroid"},{"pass_mobile":"tes","user_mobile":"tes"},{"pass_mobile":"tesdua","user_mobile":"tes2"}] is of type org.json.JSONArray at character 200 of {[{"user_mobile":"affan","pass_mobile":"affanganteng"},{"user_mobile":"affandroid","pass_mobile":"affandroid1"},{"user_mobile":"tes","pass_mobile":"tes"},{"user_mobile":"tes2","pass_mobile":"tesdua"}]}
03-10 11:35:00.868: D/dalvikvm(644): GC_EXTERNAL_ALLOC freed 1014 objects / 69872 bytes in 71ms
03-10 11:35:03.629: E/JSON Parser(644): Error parsing data org.json.JSONException: Value [{"pass_mobile":"affanganteng","user_mobile":"affan"},{"pass_mobile":"affandroid1","user_mobile":"affandroid"},{"pass_mobile":"tes","user_mobile":"tes"},{"pass_mobile":"tesdua","user_mobile":"tes2"}] of type org.json.JSONArray cannot be converted to JSONObject
03-10 11:40:58.798: D/dalvikvm(671): GC_EXTERNAL_ALLOC freed 744 objects / 59488 bytes in 80ms
03-10 11:41:03.128: E/JSON Parser(671): Error parsing data org.json.JSONException: Value [{"pass_mobile":"affanganteng","user_mobile":"affan"},{"pass_mobile":"affandroid1","user_mobile":"affandroid"},{"pass_mobile":"tes","user_mobile":"tes"},{"pass_mobile":"tesdua","user_mobile":"tes2"}] of type org.json.JSONArray cannot be converted to JSONObject
实际上我想从我的sql获取数据，然后使用JSON将其解析为listview。 我希望你能帮助我！
这是我的主要活动：
package last.project.CuliGUI;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class AndroidJSONParsingActivity extends ListActivity {
// url to make request
private static String url = "http://10.0.2.2/culigui/getdatausermobile_2.php";
// JSON Node names
//private static final String TAG_LISTUSERMOBILE = "listusermobile";
private static final String TAG_USER_MOBILE = "user_mobile";
private static final String TAG_PASS_MOBILE = "pass_mobile";
// contacts JSONArray
JSONArray listusermobile = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.menu_view_all);
// Hashmap for ListView
ArrayList<HashMap<String, String>> userList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
//listusermobile = json.getJSONArray(TAG_LISTUSERMOBILE);
listusermobile = json.getJSONArray(null);
// looping through All Contacts
for(int i = 0; i < listusermobile.length(); i++){
JSONObject c = listusermobile.getJSONObject(i);
// Storing each json item in variable
String username = c.getString(TAG_USER_MOBILE);
String password = c.getString(TAG_PASS_MOBILE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_USER_MOBILE, username);
map.put(TAG_PASS_MOBILE, password);
// adding HashList to ArrayList
userList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(this, userList,
R.layout.menu_view_all,
new String[] { TAG_USER_MOBILE, TAG_PASS_MOBILE}, new int[] {
R.id.name, R.id.pass });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String pass = ((TextView) view.findViewById(R.id.pass)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
in.putExtra(TAG_USER_MOBILE, name);
in.putExtra(TAG_PASS_MOBILE, pass);
startActivity(in);
}
});
}
}
这里是我的JSONParser类：
package last.project.CuliGUI;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
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, "iso-8859-1"), 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 " + e.toString());
}
// return JSON String
return jObj;
}
}
这是php：
<?php
$link = mysql_connect('localhost', 'root', '') or die('Cannot connect to the DB');
mysql_select_db('culigui', $link) or die('Cannot select the DB');
$result = sql2json("SELECT * FROM data_mobile");
echo $result;
//Function will take an SQL query as an argument and format the resulting data as a
// json(JavaScript Object Notation) string and return it.
function sql2json($query) {
$data_sql = mysql_query($query) or die("'';//" . mysql_error());// If an error has occurred,
// make the error a js comment so that a javascript error will NOT be invoked
$json_str = ""; //Init the JSON string.
if($total = mysql_num_rows($data_sql)) { //See if there is anything in the query
$json_str .= "[\n";
$row_count = 0;
while($data = mysql_fetch_assoc($data_sql)) {
if(count($data) > 1) $json_str .= "{\n";
$count = 0;
foreach($data as $key => $value) {
//If it is an associative array we want it in the format of "key":"value"
if(count($data) > 1) $json_str .= "\"$key\":\"$value\"";
else $json_str .= "\"$value\"";
//Make sure that the last item don't have a ',' (comma)
$count++;
if($count < count($data)) $json_str .= ",\n";
}
$row_count++;
if(count($data) > 1) $json_str .= "}\n";
//Make sure that the last item don't have a ',' (comma)
if($row_count < $total) $json_str .= ",\n";
}
$json_str .= "]\n";
}
//Replace the '\n's - make it faster - but at the price of bad redability.
$json_str = str_replace("\n","",$json_str); //Comment this out when you are debugging the script
//Finally, output the data
return $json_str;
}
?>
答案 0 :(得分：0)
首先，以下是 NOT 有效的JSON对象：
{
[
{
"user_mobile": "affan",
"pass_mobile": "affanganteng"
},
{
"user_mobile": "affandroid",
"pass_mobile": "affandroid1"
},
{
"user_mobile": "tes",
"pass_mobile": "tes"
},
{
"user_mobile": "tes2",
"pass_mobile": "tesdua"
}
]
}
在您的JAVA代码中，您正在迭代JSON对象，并获取Sub JSON对象..
JSONObject c = listusermobile.getJSONObject(i);
但是在JSON对象中，你持有JSON Array ( [] )，而不是JSON Object ( {} ) ..但是你正在尝试 TypeCast JSON Array进入JSON Object.这就是造成错误的原因......
注意：您始终可以在JSONLint.com验证“VALID JSONObject”和“VALID JSONArray”