返回联系人选择器结果时Android RunTimeException？

Question

尝试从联系人选择器中检索返回的结果时出现此错误。

10-18 09:03:14.704: ERROR/AndroidRuntime(14003): 
    Caused by: java.lang.RuntimeException: 
    Failure delivering result ResultInfo {
        who=null, 
        request=1001, 
        result=-1, 
        data=Intent { 
            dat=content://com.android.contacts/data/42 flg=0x1 (has extras) 
        }
    } 
    to activity {
        com.fttech/com.fttech.EditCreate
    }: 
    java.lang.NullPointerException

以下是我检索结果并返回所选联系人的方式。它只对某些联系人这样做。

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode) {  
        case (CONTACT_PICKER_RESULT):  
            if (resultCode == Activity.RESULT_OK) {  
                Uri contactData = data.getData();  
                Cursor contact = managedQuery(contactData, null, null, null, null);  
                if (contact.moveToFirst()) {  
                  number = contact.getString(contact.getColumnIndexOrThrow(Phone.NUMBER));

                  if(currentNumber.isEmpty()){
                      numbers.setText(number);
                  }else{
                       numbers.setText(currentNumber +","+number);
                  }
                }  
            }  
            break;  

        }//getContactInfo

我如何修复此问题或以防御方式对此进行编码？