大家 我是Android的新手。
我的申请中有错误。
这是我捕获的错误图片。 enter link description here
你能帮我解决一下吗？
非常感谢。
这是我的代码：
public class DBAdapter
{
public static final String UPDATEDATE = "UpdateDate";
//Declare fields in PersonInfo
public static final String ROWID = "_id";
public static final String PT_FirstName = "FirstName";
public static final String PT_SecondName = "SecondName";
public static final String PT_Gender = "Gender";
public static final String PT_PatientId = "PatientId";
public static final String PT_PeopleId = "PeopleId";
public static final String PT_TreatmentRight = "TreatmentRight";
public static final String PT_Birthday = "Birthday";
public static final String PT_Address = "Address";
public static final String PT_HomePhone = "HomePhone";
public static final String PT_CellPhone = "CellPhone";
public static final String PT_Email = "Email";
public static final String PT_ContactName = "ContactName";
public static final String PT_ContactPhone = "ContactPhone";
public static final String PT_Occupation = "Occupation";
public static final String PT_BloodType ="BloodType";
public static final String PT_Prefix = "Prefix";
public static final String PT_Province = "Province";
public static final String PT_PatientType = "PatientType";
private static final String DATABASE_CREATE =
"create table PatientInfo (_id integer primary key autoincrement, "
+ "PatientId text ,PatientType text , Prefix text , Gender text, "
+ "FirstName text, SecondName text, PeopleId text, TreatmentRight text, "
+ "Birthday text, BloodType text, Occupation text, Address text, "
+ "Province text, HomePhone text, CellPhone text, Email text, "
+ "ContactName text, ContactPhone text);";
private static final String DATABASE_NAME = "clinic.db";
public static final String tbPatient = "PatientInfo";
private static final int DATABASE_VERSION = 2;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx)
{
DBHelper = new DatabaseHelper(ctx);
}
//start database helper class
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db)
{
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion,
int newVersion)
{
//nothing for now
}
}
//end database helper class
//---opens the database---
public DBAdapter open() throws SQLiteException
{
db = DBHelper.getWritableDatabase();
return this;
}
//---closes the database---
public void close()
{
db.close();
DBHelper.close();
}
public Cursor getPersonList(){
return db.query(tbPatient, new String[] {
ROWID,
PT_PatientId,
PT_PatientType,
PT_Prefix,
PT_Gender,
PT_FirstName,
PT_SecondName,
PT_PeopleId,
PT_TreatmentRight,
PT_Birthday,
PT_BloodType,
PT_Occupation,
PT_Address,
PT_Province,
PT_HomePhone,
PT_CellPhone,
PT_Email,
PT_ContactName,
PT_ContactPhone},
null,
null,
null,
null,
null,
null);
}
public long insertPerson(String patientid,String patienttype,String prefix,String gender,String firstname,
String secondname,String peopleid,String treatmentright,String birthday,
String bloodtype,String occupation,String address,String province,
String homephone,String cellphone,String email,String contactname,
String contactphone) {
ContentValues initialValues = new ContentValues();
initialValues.put(PT_PatientId,patientid);
initialValues.put(PT_PatientType,patienttype);
initialValues.put(PT_Prefix,prefix);
initialValues.put(PT_Gender,gender);
initialValues.put(PT_FirstName,firstname);
initialValues.put(PT_SecondName,secondname);
initialValues.put(PT_PeopleId,peopleid);
initialValues.put(PT_TreatmentRight,treatmentright);
initialValues.put(PT_Birthday,birthday);
initialValues.put(PT_BloodType,bloodtype);
initialValues.put(PT_Occupation,occupation);
initialValues.put(PT_Address,address);
initialValues.put(PT_Province,province);
initialValues.put(PT_HomePhone,homephone);
initialValues.put(PT_CellPhone,cellphone);
initialValues.put(PT_Email,email);
initialValues.put(PT_ContactName,contactname);
initialValues.put(PT_ContactPhone,contactphone);
return db.insert(tbPatient, null, initialValues);
}
public boolean updatePerson(long recordid, String patientid,String patienttype,String prefix,String gender,String firstname,
String secondname,String peopleid,String treatmentright,String birthday,
String bloodtype,String occupation,String address,String province,
String homephone,String cellphone,String email,String contactname,
String contactphone) {
ContentValues args = new ContentValues();
args.put(PT_PatientId,patientid);
args.put(PT_PatientType,patienttype);
args.put(PT_Prefix,prefix);
args.put(PT_Gender,gender);
args.put(PT_FirstName,firstname);
args.put(PT_SecondName,secondname);
args.put(PT_PeopleId,peopleid);
args.put(PT_TreatmentRight,treatmentright);
args.put(PT_Birthday,birthday);
args.put(PT_BloodType,bloodtype);
args.put(PT_Occupation,occupation);
args.put(PT_Address,address);
args.put(PT_Province,province);
args.put(PT_HomePhone,homephone);
args.put(PT_CellPhone,cellphone);
args.put(PT_Email,email);
args.put(PT_ContactName,contactname);
args.put(PT_ContactPhone,contactphone);
return db.update(tbPatient, args,
ROWID + "=" + recordid, null) > 0;
}
public boolean deletePerson(long recordid)
{
return db.delete(tbPatient, ROWID +
"=" + recordid, null) > 0;
}
public Cursor fetchNote(long rowId) throws SQLException {
Cursor mCursor =
db.query(tbPatient, new String[] {
ROWID,
PT_PatientId,
PT_PatientType,
PT_Prefix,
PT_Gender,
PT_FirstName,
PT_SecondName,
PT_PeopleId,
PT_TreatmentRight,
PT_Birthday,
PT_BloodType,
PT_Occupation,
PT_Address,
PT_Province,
PT_HomePhone,
PT_CellPhone,
PT_Email,
PT_ContactName,
PT_ContactPhone}, ROWID + "=" + rowId, null,
null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
}
//////////////////////////////////////////////////////////////////////////////////////
public class PatientInfo extends Activity{
private TextView firstNameEdt;
private TextView patientIdEdt;
private TextView lastNameEdt;
private TextView peopleIdEdt;
private TextView birthdayEdt;
private TextView addressEdt;
private TextView homePhoneEdt;
private TextView cellPhoneEdt;
private TextView emailEdt;
private TextView contactNameEdt;
private TextView contactPhoneEdt;
private TextView GenderEdt;
private TextView OccupationEdt;
private TextView BloodTypeEdt;
private TextView PrefixEdt;
private TextView ProvinceEdt;
private TextView TreatmentRightEdt;
private TextView PatientTypeEdt ;
private DBAdapter dbPatient;
private Button exitBtn;
private Button editBtn;
private Button addAppointmentBtn;
private Long rowId;
String S_PatientType=" ";
String S_Gender=" ";
String S_Occupation=" ";
String S_BloodType=" ";
String S_Prefix=" ";
String S_Province=" ";
String S_TreatmentRight=" ";
String S_Birthday=" ";
String S_PatientId=" ";
String S_FirstName=" ";
String S_SecondName=" ";
String S_PeopleId=" ";
String S_Address=" ";
String S_HomePhone=" ";
String S_CellPhone=" ";
String S_Email=" ";
String S_ContactName =" ";
String S_ContactPhone =" ";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dbPatient = new DBAdapter(this);
dbPatient.open();
setContentView(R.layout.patientinfo);
setBinding();
rowId = savedInstanceState != null ? savedInstanceState.getLong(DBAdapter.ROWID)
: null;
if (rowId == null) {
Bundle extras = getIntent().getExtras();
rowId = extras != null ? extras.getLong(DBAdapter.ROWID)
: null;
}
populateFields();
// dataPreparation();
setEvent();
}
private void populateFields() {
if (rowId != null) {
Cursor note = dbPatient.fetchNote(rowId);
startManagingCursor(note);
firstNameEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_FirstName)));
lastNameEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_SecondName)));
GenderEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_Gender)));
patientIdEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_PatientId)));
peopleIdEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_PeopleId)));
TreatmentRightEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_TreatmentRight)));
birthdayEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_Birthday)));
addressEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_Address)));
homePhoneEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_HomePhone)));
cellPhoneEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_CellPhone)));
emailEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_Email)));
contactNameEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_ContactName)));
contactPhoneEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_ContactPhone)));
OccupationEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_Occupation)));
BloodTypeEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_BloodType)));
PrefixEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_Prefix)));
ProvinceEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_Province )));
PatientTypeEdt.setText(note.getString(
note.getColumnIndexOrThrow(DBAdapter.PT_PatientType)));
}
}
private void setBinding(){
editBtn=(Button) findViewById(R.id.edit);
exitBtn=(Button) findViewById(R.id.exit);
dbPatient = new DBAdapter(this);
addAppointmentBtn=(Button) findViewById(R.id.addAppointment);
PatientTypeEdt = (TextView) findViewById(R.id.patient_Type);
GenderEdt = (TextView) findViewById(R.id.gender);
OccupationEdt = (TextView) findViewById(R.id.occupation);
BloodTypeEdt = (TextView) findViewById(R.id.blood_Type);
PrefixEdt = (TextView) findViewById(R.id.prefix);
ProvinceEdt = (TextView) findViewById(R.id.province);
TreatmentRightEdt = (TextView) findViewById(R.id.treatment_Right);
birthdayEdt=(TextView) findViewById(R.id.birthday);
patientIdEdt = (TextView) findViewById(R.id.patient_id);
firstNameEdt = (TextView) findViewById(R.id.first_Name);
lastNameEdt= (TextView) findViewById(R.id.last_Name);
peopleIdEdt = (TextView) findViewById(R.id.id2);
addressEdt = (TextView) findViewById(R.id.address);
homePhoneEdt = (TextView) findViewById(R.id.home_Phone);
cellPhoneEdt = (TextView) findViewById(R.id.cell_Phone);
emailEdt = (TextView) findViewById(R.id.email);
contactNameEdt = (TextView) findViewById(R.id.contact_Name);
contactPhoneEdt = (TextView) findViewById(R.id.contact_Phone);
}
private void setEvent() {
// TODO Auto-generated method stub
addAppointmentBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Intent showLinearLayout = new Intent(PatientInfo.this,AddAppointment.class);
startActivity(showLinearLayout);
}
});
exitBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Intent showLinearLayout = new Intent(PatientInfo.this,MainActivity.class);
startActivity(showLinearLayout);
}
});
editBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Intent showLinearLayout = new Intent(PatientInfo.this,AddPatient.class);
startActivity(showLinearLayout);
}
});
}
//////////////////////////////////////////////////////////////////////////////////////
public class SearchPatient extends ListActivity{
private DBAdapter dbPatient;
private EditText appointmentDateEdt;
private Spinner typeSelectSpn;
private Button exitBtn;
private Button searchBtn;
private Cursor personListCursor;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.searchpatient);
setBinding();
dataPreparation();
listData();
setEvent();
}
private void setBinding(){
typeSelectSpn = (Spinner) findViewById(R.id.search_Type);
exitBtn=(Button) findViewById(R.id.exit);
searchBtn=(Button) findViewById(R.id.search);
dbPatient = new DBAdapter(this);
}
private void setEvent() {
// TODO Auto-generated method stub
searchBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Intent showLinearLayout = new Intent(SearchPatient.this,PatientInfo.class);
startActivity(showLinearLayout);
Bundle b = new Bundle();
b.putLong("ROWID", 0);
showLinearLayout.putExtras(b);
startActivity(showLinearLayout);
}
});
}
private void listData(){
dbPatient.open();
personListCursor = dbPatient.getPersonList();
startManagingCursor(personListCursor);
String[] from = new String[] { DBAdapter.PT_PatientId,DBAdapter.PT_FirstName, DBAdapter.PT_SecondName,DBAdapter.PT_PatientType };
int[] to = new int[] { R.id.patient_id2, R.id.firstname2, R.id.lastname2, R.id.patient_type2};
// Now create an array adapter and set it to display using our row
SimpleCursorAdapter personList =
new SimpleCursorAdapter(this, R.layout.datarow, personListCursor, from, to){
};
setListAdapter(personList);
//dbPatient.close();
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
Intent i = new Intent(this, PatientInfo.class);
i.putExtra(DBAdapter.ROWID, id);
startActivity(i);
}
private void dataPreparation()
{
ArrayAdapter<CharSequence> Adapter1 = ArrayAdapter.createFromResource(this, R.array.search,
android.R.layout.simple_spinner_item);
Adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
typeSelectSpn.setAdapter(Adapter1);
}
}
答案 0 :(得分：0)
db中 fetchNote()可能为空。也许您没有通过调用open()打开数据库？
答案 1 :(得分：0)
根据您的堆栈跟踪，db中的fetchNote()似乎为空，因为您尚未调用open()。该方法中没有任何其他内容会显示会导致NullPointerException。
答案 2 :(得分：0)
您可以尝试在fetchnote方法中进行显式的null检查：
public Cursor fetchNote(long rowId) throws SQLException {
if(db==null){
return null;
}
Cursor mCursor =
db.query(tbPatient, new String[] {
ROWID,
PT_PatientId,
PT_PatientType,
PT_Prefix,
PT_Gender,
PT_FirstName,
PT_SecondName,
PT_PeopleId,
PT_TreatmentRight,
PT_Birthday,
PT_BloodType,
PT_Occupation,
PT_Address,
PT_Province,
PT_HomePhone,
PT_CellPhone,
PT_Email,
PT_ContactName,
PT_ContactPhone}, ROWID + "=" + rowId, null,
null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
但是你的open方法似乎初始化了“db”。也许它不叫？或者DBHelper.getWritableDatabase（）可能返回null？
我还建议如下：
//---opens the database---
public DBAdapter open() throws SQLiteException
{
db = DBHelper.getWritableDatabase();
if(db==null)
throw new RuntimeException("Database could not be opened");
return this;
}
答案 3 :(得分：0)
NullPointer进入 DBAdapter 类中的 fetchNote 方法： 光标在那里返回null ..
检查确切的代码行： DBAdapter行号。 192