我有一个显示属性名称的listView，它运行良好，但我在显示每个announcement的详细视图时遇到问题。当您单击listView中的项目时，我将获得空的activity_details，并且调试器中出现以下错误：
W/System.err: org.json.JSONException: Value No of type java.lang.String cannot be converted to JSONArray
W/System.err: at org.json.JSON.typeMismatch(JSON.java:111)
W/System.err: at org.json.JSONArray.<init>(JSONArray.java:96)
W/System.err: at org.json.JSONArray.<init>(JSONArray.java:108)
W/System.err: at com.example.said.populate.DetailsActivity$GetHttpResponse.doInBackground(DetailsActivity.java:205)
W/System.err: at com.example.said.populate.DetailsActivity$GetHttpResponse.doInBackground(DetailsActivity.java:180)
W/System.err: at android.os.AsyncTask$2.call(AsyncTask.java:288)
W/System.err: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
W/System.err: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
W/System.err: at java.lang.Thread.run(Thread.java:831)
Disconnected from the target VM, address: 'localhost:8600', transport: 'socket'
这是用于连接的PHP文件：
<?php
if($_SERVER['REQUEST_METHOD']=='POST'){
include 'DatabaseConfig.php';
$StudentID= $_POST['propertyid'];
// Create connection
$conn = new mysqli($HostName, $HostUser, $HostPass, $DatabaseName);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT * FROM estate2 where id = '$propertyid'" ;
$result = $conn->query($sql);
if ($result->num_rows >0) {
while($row[] = $result->fetch_assoc()) {
$tem = $row;
$json = json_encode($tem);
}
} else {
echo "No Results Found.";
}
echo $json;
$conn->close();
}
?>
以下是我提供的DetailsActivity：
public class DetailsActivity extends AppCompatActivity {
HttpParse httpParse = new HttpParse();
ProgressDialog pDialog;
// Http Url For Filter Student Data from Id Sent from previous activity.
String HttpURL = "https://sultonkhuja1111.000webhostapp.com/MobApp/detail.php";
String finalResult ;
HashMap<String,String> hashMap = new HashMap<>();
String ParseResult ;
HashMap<String,String> ResultHash = new HashMap<>();
String FinalJSonObject ;
TextView NAME,PHONE_NUMBER,CLASS;
String NameHolder, NumberHolder, ClassHolder;
Button UpdateButton, DeleteButton;
String TempItem;
ProgressDialog progressDialog2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_details);
NAME = (TextView)findViewById(R.id.textName);
PHONE_NUMBER = (TextView)findViewById(R.id.textPhone);
CLASS = (TextView)findViewById(R.id.textClass);
UpdateButton = (Button)findViewById(R.id.buttonUpdate);
DeleteButton = (Button)findViewById(R.id.buttonDelete);
//Receiving the ListView Clicked item value send by previous activity.
TempItem = getIntent().getStringExtra("ListViewValue");
//Calling method to filter Student Record and open selected record.
HttpWebCall(TempItem);
}
//Method to show current record Current Selected Record
public void HttpWebCall(final String PreviousListViewClickedItem){
class HttpWebCallFunction extends AsyncTask<String,Void,String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = ProgressDialog.show(DetailsActivity.this,"Loading Data",null,true,true);
}
@Override
protected void onPostExecute(String httpResponseMsg) {
super.onPostExecute(httpResponseMsg);
pDialog.dismiss();
//Storing Complete JSon Object into String Variable.
FinalJSonObject = httpResponseMsg ;
//Parsing the Stored JSOn String to GetHttpResponse Method.
new GetHttpResponse(DetailsActivity.this).execute();
}
@Override
protected String doInBackground(String... params) {
ResultHash.put("propertyid",params[0]);
ParseResult = httpParse.postRequest(ResultHash, HttpURL);
return ParseResult;
}
}
HttpWebCallFunction httpWebCallFunction = new HttpWebCallFunction();
httpWebCallFunction.execute(PreviousListViewClickedItem);
}
// Parsing Complete JSON Object.
private class GetHttpResponse extends AsyncTask<Void, Void, Void>
{
public Context context;
public GetHttpResponse(Context context)
{
this.context = context;
}
@Override
protected void onPreExecute()
{
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... arg0)
{
try
{
if(FinalJSonObject != null)
{
JSONArray jsonArray = null;
try {
jsonArray = new JSONArray(FinalJSonObject);
JSONObject jsonObject;
for(int i=0; i<jsonArray.length(); i++)
{
jsonObject = jsonArray.getJSONObject(i);
// Storing Student Name, Phone Number, Class into Variables.
NameHolder = jsonObject.getString("property_name").toString() ;
NumberHolder = jsonObject.getString("price").toString() ;
ClassHolder = jsonObject.getString("description").toString() ;
}
}
catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result)
{
// Setting Student Name, Phone Number, Class into TextView after done all process .
NAME.setText(NameHolder);
PHONE_NUMBER.setText(NumberHolder);
CLASS.setText(ClassHolder);
}
}
}
和ShowingAllEstatesActivity：
public class ShowingAllEstatesActivity extends AppCompatActivity {
ListView SubjectListView;
ProgressBar progressBarSubject;
String ServerURL = "http://sultonkhuja1111.000webhostapp.com/MobApp/Estate.php";
List<String> IdList = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_showing_all_estates);
SubjectListView = (ListView)findViewById(R.id.listview1);
progressBarSubject = (ProgressBar)findViewById(R.id.progressBar);
new GetHttpResponse(ShowingAllEstatesActivity.this).execute();
//Adding ListView Item click Listener.
SubjectListView.setOnItemClickListener(new AdapterView.OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// TODO Auto-generated method stub
Intent intent = new Intent(ShowingAllEstatesActivity.this, DetailsActivity.class);
// Sending ListView clicked value using intent.
intent.putExtra("ListViewValue", IdList.get(position).toString());
startActivity(intent);
//Finishing current activity after open next activity.
finish();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_listing, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case R.id.addNew:
startActivity(new Intent(this, AddPropertyActivity.class));
break;
}
return true;
}
private class GetHttpResponse extends AsyncTask<Void, Void, Void>
{
public Context context;
String ResultHolder;
List<subjects> subjectsList;
public GetHttpResponse(Context context)
{
this.context = context;
}
@Override
protected void onPreExecute()
{
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... arg0)
{
HttpServicesClass httpServiceObject = new HttpServicesClass(ServerURL);
try
{
httpServiceObject.ExecutePostRequest();
if(httpServiceObject.getResponseCode() == 200)
{
ResultHolder = httpServiceObject.getResponse();
if(ResultHolder != null)
{
JSONArray jsonArray = null;
try {
jsonArray = new JSONArray(ResultHolder);
JSONObject jsonObject;
subjects subjects;
subjectsList = new ArrayList<subjects>();
for(int i=0; i<jsonArray.length(); i++)
{
subjects = new subjects();
jsonObject = jsonArray.getJSONObject(i);
IdList.add(jsonObject.getString("propertyid").toString());
subjects.SubjectName = jsonObject.getString("property_name");
subjectsList.add(subjects);
}
}
catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
else
{
Toast.makeText(context, httpServiceObject.getErrorMessage(), Toast.LENGTH_SHORT).show();
}
}
catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result)
{
progressBarSubject.setVisibility(View.GONE);
SubjectListView.setVisibility(View.VISIBLE);
if(subjectsList != null)
{
ListAdapter adapter = new ListAdapter(subjectsList, context);
SubjectListView.setAdapter(adapter);
}
}
}
}
这是获取HttpUrl，detail.php：
的代码<?php
if($_SERVER['REQUEST_METHOD']=='POST'){
include 'DatabaseConfig.php';
$propertyid= $_POST['propertyid'];
// Create connection
$conn = new mysqli($HostName, $HostUser, $HostPass, $DatabaseName);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT * FROM estate2 where propertyid = '$propertyid'";
$result = $conn->query($sql);
if ($result->num_rows >0) {
while($row[] = $result->fetch_assoc()) {
$tem = $row;
$json = json_encode($tem);
}
} else {
echo "No Results Found.";
}
echo $json;
$conn->close();
}
?>
答案 0 :(得分：1)
我觉得你的HttpURL看起来并不好看。如果这个网址没有给出JSON响应，那么它会产生同样的问题。