我有需要使用PHP应用程序的工作完美的Android和MySQL数据库之间的连接android应用。 只显示用户操作不起作用这种方法在一些数据的列表显示给用户。
谁能帮我解决这个错误?
所添加的代码的结果是
04-14 23:17:57.766: D/this from internet(2367): usersList.get(position).getDate() is null
logcat的错误
04-14 21:59:22.170: E/AndroidRuntime(1951): FATAL EXCEPTION: main
04-14 21:59:22.170: E/AndroidRuntime(1951): java.lang.NullPointerException
04-14 21:59:22.170: E/AndroidRuntime(1951): at com.devleb.loginDemo.CustomAdapter.getView(CustomAdapter.java:60)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.AbsListView.obtainView(AbsListView.java:2177)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.ListView.makeAndAddView(ListView.java:1840)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.ListView.fillDown(ListView.java:675)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.ListView.fillFromTop(ListView.java:736)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.ListView.layoutChildren(ListView.java:1655)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.AbsListView.onLayout(AbsListView.java:2012)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.View.layout(View.java:14289)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.ViewGroup.layout(ViewGroup.java:4562)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.View.layout(View.java:14289)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.ViewGroup.layout(ViewGroup.java:4562)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.View.layout(View.java:14289)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.ViewGroup.layout(ViewGroup.java:4562)
04-14 21:59:22.170: E/AndroidRuntime(1951): at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:349)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.View.layout(View.java:14289)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.ViewGroup.layout(ViewGroup.java:4562)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.View.layout(View.java:14289)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.ViewGroup.layout(ViewGroup.java:4562)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1976)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1730)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.Choreographer.doCallbacks(Choreographer.java:562)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.Choreographer.doFrame(Choreographer.java:532)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.os.Handler.handleCallback(Handler.java:730)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.os.Handler.dispatchMessage(Handler.java:92)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.os.Looper.loop(Looper.java:137)
04-14 21:59:22.170: E/AndroidRuntime(1951): at android.app.ActivityThread.main(ActivityThread.java:5103)
04-14 21:59:22.170: E/AndroidRuntime(1951): at java.lang.reflect.Method.invokeNative(Native Method)
04-14 21:59:22.170: E/AndroidRuntime(1951): at java.lang.reflect.Method.invoke(Method.java:525)
04-14 21:59:22.170: E/AndroidRuntime(1951): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
04-14 21:59:22.170: E/AndroidRuntime(1951): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
04-14 21:59:22.170: E/AndroidRuntime(1951): at dalvik.system.NativeStart.main(Native Method)
list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/background_1"
android:orientation="vertical" >
<TextView
android:id="@+id/uid"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<TextView
android:id="@+id/name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingLeft="6dip"
android:paddingTop="20dip"
android:text="text view"
android:textColor="#FFFFFF"
android:textSize="17dip"
android:textStyle="bold" />
<TextView
android:id="@+id/txtCreateDate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="TextView"
android:textColor="#FFFFFF" />
</RelativeLayout>
User.java
package com.devleb.loginDemo;
import java.util.HashMap;
//@SuppressWarnings("serial")
public class User extends HashMap<String, String> {
/**
*
*/
String name;
String date;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
}
CustomAdapter.java
package com.devleb.loginDemo;
import java.util.ArrayList;
import java.util.Date;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
public class CustomAdapter extends BaseAdapter {
private static ArrayList<User> usersList = new ArrayList<User>();
// private static ArrayList name, date;
LayoutInflater layoutInflater;
String[] userName;
Date[] createdDate;
Context context;
@SuppressWarnings("rawtypes")
public CustomAdapter(ArrayList<User> result, Context c) {
usersList = result;
context = c;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return usersList.size();
}
@Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return usersList.get(arg0);
}
@Override
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return arg0;
}
@Override
public View getView(int position, View arg1, ViewGroup parent) {
// TODO Auto-generated method stub
layoutInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View row = null;
row = layoutInflater.inflate(R.layout.list_item, parent, false);
TextView txtCreateDate = (TextView) row
.findViewById(R.id.txtCreateDate);
txtCreateDate.setText(usersList.get(position).getDate());
TextView txtName = (TextView) row.findViewById(R.id.name);
txtName.setText(usersList.get(position).getName());
return row;
}
}
UserListActivity.java
package com.devleb.loginDemo;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.app.ListActivity;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
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;
import android.widget.Toast;
public class UserListActivity extends ListActivity {
JSONParser jsonParser = new JSONParser();
// ArrayList<HashMap<String, String>> usersList;
// **** added from internt*************///
@SuppressWarnings("rawtypes")
ArrayList<User> arrayList_userList;
ListView lvUsers;
// **** added from internt*************///
private static String url_display_user = "http://10.0.3.2/android_connect/display_user.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_MESSAGE = "message";
private static final String TAG_ID = "id";
private static final String TAG_USERS = "userlist";
private static final String TAG_USER = "user";
private static final String TAG_DATE = "date";
// private static final String TAG_NAME = "name";
// employees JSONArray
JSONArray users = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user_list);
// usersList = new ArrayList<HashMap<String, String>>();
new getUserList().execute();
// getListView
lvUsers = (ListView) findViewById(android.R.id.list);
lvUsers.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View view, int arg2,
long arg3) {
// String id = ((TextView)
// view.findViewById(R.id.uid)).getText()
// .toString();
// Intent in = new Intent(getBaseContext(), StatusList.class);
// in.putExtra(TAG_ID, uid);
// startActivity(in);
}
});
}
class getUserList extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
UserListActivity.this.setProgressBarIndeterminateVisibility(true);
}
@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
// Building Parameters
List<NameValuePair> parametres = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jsonParser.makeHttpRequest(url_display_user,
"GET", parametres);
// Check your log cat for JSON reponse
Log.d("All Users: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
users = json.getJSONArray(TAG_USERS);
// looping through All Users
for (int i = 0; i < users.length(); i++) {
JSONObject c = users.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String user = c.getString(TAG_USER);
String cdate = c.getString(TAG_DATE).toString();
// creating new HashMap
User map = new User();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_USER, user);
map.put(TAG_DATE, cdate);
// adding HashList to ArrayList
// usersList.add(map);
arrayList_userList.add(map);
}
// ***********************************//
// From the internet
// arrayList_userList = new
// ArrayList<User>(usersList.value())
// **********************************//
return json.getString(TAG_MESSAGE);
} else {
return json.getString(TAG_MESSAGE);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String result) {
// dismiss the dialog after getting all products
if (result != null) {
UserListActivity.this
.setProgressBarIndeterminateVisibility(false);
/**
* Updating parsed JSON data into ListView
* */
/*
* ListAdapter adapter = new
* SimpleAdapter(UserListActivity.this, usersList,
* R.layout.list_item, new String[] { TAG_ID, TAG_USER }, new
* int[] { R.id.uid, R.id.name }); // updating listview
* setListAdapter(adapter);
*/
lvUsers.setAdapter(new CustomAdapter(arrayList_userList,
getBaseContext()));
Toast.makeText(getBaseContext(), result, Toast.LENGTH_LONG)
.show();
}
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.user_list, menu);
return true;
}
}