2016-09-15 73 views
0

在這裏,我從移動設備獲取姓名,電子郵件,電話號碼並嘗試上傳到服務器..如果聯繫人包含姓名,電子郵件和電話號碼,則值將被成功插入..但如果任何領域是空的它是拋出NULL指針異常。如何避免這一個..我的意思是,如果聯繫人不包含電子郵件,它應該至少發送名稱和電話號碼。將聯繫人上傳到服務器時出現空指針異常

這是我的代碼。

public class DisplayContact1 extends Activity { 

    private static String TAG = WorkDetails1.class.getSimpleName(); 

    Button select; 

    private String vault; 
    List<AddressBookContact> list; 

    public static final String kvault = "vault_no"; 
    public static final String kname = "name"; 
    public static final String kphone = "phone"; 
    public static final String kemail = "email"; 
    public static final String kcontacts = "contacts"; 

    public static final String SHARED_PREF_NAME = "myloginapp"; 

    public static final String UPLOAD_URL = "http://oursite.com/contacts_1.php"; 

    private static final int MY_PERMISSIONS_REQUEST_READ_CONTACTS = 1; 

    Cursor cursor; 
    LongSparseArray<AddressBookContact> array; 
    long start; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     //getActionBar().setDisplayShowTitleEnabled(false); 
     setContentView(R.layout.display); 

     SharedPreferences sharedPreferences = getSharedPreferences(ProfileLogin.SHARED_PREF_NAME, MODE_PRIVATE); 

     vault = sharedPreferences.getString(ProfileLogin.EMAIL_SHARED_PREF,"Not Available"); 
     getAllContacts(this.getContentResolver()); 

    } 

    public void getAllContacts(ContentResolver cr) { 

     int result = ContextCompat.checkSelfPermission(DisplayContact1.this, Manifest.permission.READ_CONTACTS); 
     if (result == PackageManager.PERMISSION_GRANTED){ 

      //fetches contacts from the phone contact list and displays in ascending order 
      list = new LinkedList<AddressBookContact>(); 
      array = new LongSparseArray<AddressBookContact>(); 
      start = System.currentTimeMillis(); 

      String[] projection = { 
        ContactsContract.Data.MIMETYPE, 
        ContactsContract.Data.CONTACT_ID, 
        ContactsContract.Contacts.DISPLAY_NAME, 
        ContactsContract.CommonDataKinds.Contactables.DATA, 
        ContactsContract.CommonDataKinds.Contactables.TYPE, 
      }; 
      String selection = ContactsContract.Data.MIMETYPE + " in (?, ?)"; 
      String[] selectionArgs = { 
        ContactsContract.CommonDataKinds.Email.CONTENT_ITEM_TYPE, 
        ContactsContract.CommonDataKinds.Phone.CONTENT_ITEM_TYPE, 
      }; 
      String sortOrder = ContactsContract.Contacts.SORT_KEY_ALTERNATIVE; 

      Uri uri = ContactsContract.Data.CONTENT_URI; 
// we could also use Uri uri = ContactsContract.Data.CONTENT_URI; 

      cursor = getContentResolver().query(uri, projection, selection, selectionArgs, sortOrder); 
      contactsdisplay(); 

     } else { 

      requestForLocationPermission(); 
     } 
    } 

    private void requestForLocationPermission() 
    { 

     if (ActivityCompat.shouldShowRequestPermissionRationale(DisplayContact1.this, Manifest.permission.READ_CONTACTS)) 
     { 
     } 
     else { 

      ActivityCompat.requestPermissions(DisplayContact1.this, new String[]{Manifest.permission.READ_CONTACTS}, MY_PERMISSIONS_REQUEST_READ_CONTACTS); 
     } 
    } 

    @Override 
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) 
    { 
     switch (requestCode) { 
      case MY_PERMISSIONS_REQUEST_READ_CONTACTS: 
       if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) 
       { 
        getAllContacts(DisplayContact1.this.getContentResolver()); 
        contactsdisplay(); 
       } 
       break; 
     } 
    } 

    public void contactsdisplay() { 

     //Cursor phones = cr.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null, null); 
     final int mimeTypeIdx = cursor.getColumnIndex(ContactsContract.Data.MIMETYPE); 
     final int idIdx = cursor.getColumnIndex(ContactsContract.Data.CONTACT_ID); 
     final int nameIdx = cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME); 
     final int dataIdx = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Contactables.DATA); 
     final int typeIdx = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Contactables.TYPE); 

     while (cursor.moveToNext()) { 
      long id = cursor.getLong(idIdx); 
      AddressBookContact addressBookContact = array.get(id); 
      if (addressBookContact == null) { 
       addressBookContact = new AddressBookContact(id, cursor.getString(nameIdx), getResources()); 
       array.put(id, addressBookContact); 
       list.add(addressBookContact); 
      } 
      int type = cursor.getInt(typeIdx); 
      String data = cursor.getString(dataIdx); 
      String mimeType = cursor.getString(mimeTypeIdx); 
      if (mimeType.equals(ContactsContract.CommonDataKinds.Email.CONTENT_ITEM_TYPE)) { 
       // mimeType == ContactsContract.CommonDataKinds.Email.CONTENT_ITEM_TYPE 
       addressBookContact.addEmail(type, data); 
      } else { 
       // mimeType == ContactsContract.CommonDataKinds.Phone.CONTENT_ITEM_TYPE 
       addressBookContact.addPhone(type, data); 
      } 
     } 
     long ms = System.currentTimeMillis() - start; 
     cursor.close(); 

// done!!! show the results... 
     int i = 1; 
     for (AddressBookContact addressBookContact : list) { 
      Log.d(TAG, "AddressBookContact #" + i++ + ": " + addressBookContact.toString(true)); 
     } 
     final String cOn = "<b><font color='#ff9900'>"; 
     final String cOff = "</font></b>"; 
     Spanned l1 = Html.fromHtml("got " + cOn + array.size() + cOff + " contacts<br/>"); 
     Spanned l2 = Html.fromHtml("query took " + cOn + ms/1000f + cOff + " s (" + cOn + ms + cOff + " ms)"); 

     Log.d(TAG, "\n\n╔══════ query execution stats ═══════"); 
     Log.d(TAG, "║ " + l1); 
     Log.d(TAG, "║ " + l2); 
     Log.d(TAG, "╚════════════════════════════════════"); 
     SpannableStringBuilder msg = new SpannableStringBuilder().append(l1).append(l2); 

     ListView lv= (ListView) findViewById(R.id.lv); 
     lv.setAdapter(new ArrayAdapter<AddressBookContact>(this, android.R.layout.simple_list_item_1, list)); 
     lv.setItemsCanFocus(false); 
     lv.setTextFilterEnabled(true); 

     select = (Button) findViewById(R.id.button1); 
     select.setOnClickListener(new View.OnClickListener() 
     { 
      @Override 
      public void onClick(View v){ 
       uploadImage(); 
      } 

     }); 
    } 

    public void uploadImage(){ 

     SharedPreferences sharedPreferences = getSharedPreferences(DisplayContact.SHARED_PREF_NAME, MODE_PRIVATE); 

     final String vault_no = vault; 

     class UploadImage extends AsyncTask<Void,Void,String> { 
      ProgressDialog loading; 
      @Override 
      protected void onPreExecute() { 
       super.onPreExecute(); 
       loading = ProgressDialog.show(DisplayContact1.this,"Please wait...","uploading",false,false); 
      } 

      @Override 
      protected void onPostExecute(String s) { 
       super.onPostExecute(s); 
       loading.dismiss(); 
       if(s.equalsIgnoreCase("Successfully Saved")){ 
        //Intent intent = new Intent(CollegeDetails.this,Work.class); 
        Toast.makeText(DisplayContact1.this, s, Toast.LENGTH_SHORT).show(); 
        // startActivity(intent); 
       }else{ 
        Toast.makeText(DisplayContact1.this,s,Toast.LENGTH_SHORT).show(); 

       } 
      } 

      @Override 
      protected String doInBackground(Void... params) { 
       RequestHandler rh = new RequestHandler(); 
       //RegisterUserClass rh = new RegisterUserClass(); 
       HashMap<String,String> param = new HashMap<String,String>(); 

       JSONArray contacts = new JSONArray(); 
       int i = 1; 
       for (AddressBookContact addressBookContact : list) { 
        try { 
         Log.d(TAG, "AddressBookContact #" + i++ + ": " + addressBookContact.toString(true)); 
         JSONObject contact = new JSONObject(); 

         contact.put(kname, addressBookContact.name.toString()); 
         contact.put(kvault, vault_no); 
         contact.put(kphone, addressBookContact.phone.toString()); 

         if(addressBookContact.email.toString()!=null) 
          contact.put(kemail, addressBookContact.email.toString()); 

         contacts.put(contact); 
        } 
        catch (JSONException e) { 
         // TODO Auto-generated catch block 
         e.printStackTrace(); 
        } 

        param.put(kcontacts, contacts.toString()); 
        System.out.println("param value.." + i++ +":"+ contacts.toString()); 
       } 
       return rh.sendPostRequest(UPLOAD_URL, param); 

      } 
     } 
     UploadImage u = new UploadImage(); 
     u.execute(); 
    } 
} 

這裏是AddressBookContact.class

public class AddressBookContact { 

    private long id; 
    private Resources res; 
    String name; 
    LongSparseArray<String> email; 
    LongSparseArray<String> phone; 

    AddressBookContact(long id, String name, Resources res) { 
     this.id = id; 
     this.name = name; 
     this.res = res; 
    } 

    @Override 
    public String toString() { 
     return toString(false); 
    } 

    public String toString(boolean rich) { 
     SpannableStringBuilder builder = new SpannableStringBuilder(); 
     if (rich) { 
      builder.append("id: ").append(Long.toString(id)) 

        .append(", name: ").append(name); 
     } else { 
      builder.append("name: ").append(name); 
     } 

     if (phone != null) { 
      builder.append("\nphone: "); 
      for (int i = 0; i < phone.size(); i++) { 
       int type = (int) phone.keyAt(i); 

       builder.append(phone.valueAt(i)); 
       if (i + 1 < phone.size()) { 
        builder.append(", "); 
       } 
      } 
     } 

     if (email != null) { 
      builder.append("\nemail: "); 
      for (int i = 0; i < email.size(); i++) { 
       int type = (int) email.keyAt(i); 

       builder.append(email.valueAt(i)); 
       if (i + 1 < email.size()) { 
        builder.append(", "); 
       } 
      } 
     } 
     return builder.toString(); 
    } 

    public void addEmail(int type, String address) { 
     if (email == null) { 
      email = new LongSparseArray<String>(); 
     } 
     email.put(type, address); 
    } 

    public void addPhone(int type, String number) { 
     if (phone == null) { 
      phone = new LongSparseArray<String>(); 
     } 
     phone.put(type, number); 
    } 
} 

如果電子郵件字段爲空,我得到空指針異常此行.. contact.put(kemail, addressBookContact.email.toString()); ..所以我已經當環路增加檢查null條件..但是,我也得到例外。

回答

1

這裏

if (addressBookContact.email.toString() != null) 

您嘗試從爲空「電子郵件」變量得到的字符串。 正確的比較是:

if (addressBookContact.email != null) 
+0

是的你是對的.. !!它的工作很好.. –

1

添加兩個條件,你下面的字符串可能不爲空,但可以 空""

if(addressBookContact.email.toString() != null && !addressBookContact.email.toString().equalsIgnoreCase("")) 
    contact.put(kemail, addressBookContact.email.toString()); 
+0

確定將檢查.. –

+0

相同error..getting空指針異常。 –

1

使用TextUtils

if(!TextUtils.isEmpty(addressBookContact.email.toString())){ 
    contact.put(kemail, addressBookContact.email.toString()); 
} 

如果kemail是義務教育領域再else條件只是通過""空值。

+0

將檢查一個.. –

+0

我得到上述代碼的NullPointerException也.. –

+1

您可以刪除'.toString()'或在'AddressBookContact類'中創建'toString()'。 – Piyush

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