Java Android Studio-尝试重新打开已关闭的对象：SQLiteDatabase

我正在制作我的第一个Android应用程序，当我使用Java时，我是一个完全的新手，因为我只使用过Python。我试图创建一个数据库，通过初始设置活动存储用户的详细信息，但是我得到了一个错误

08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:  Caused by:        java.lang.IllegalStateException: attempt to re-open an already-closed object: SQLiteDatabase: /data/user/0/fitness.essentials.fitnessessentials/databases/UserData.db
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.database.sqlite.SQLiteClosable.acquireReference(SQLiteClosable.java:55)
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.database.sqlite.SQLiteDatabase.endTransaction(SQLiteDatabase.java:525)
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:262)
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:163)
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at fitness.essentials.fitnessessentials.Database.<init>(Database.java:26)
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at fitness.essentials.fitnessessentials.SetupScreen.onCreate(SetupScreen.java:44)
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.app.Activity.performCreate(Activity.java:6876)
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1135)
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3206)
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3349) 
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.app.ActivityThread.access$1100(ActivityThread.java:221) 
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794) 
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102) 
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:158) 
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:7224) 
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method) 
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
08-13 17:24:27.400 10263-10263/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 

这是我试图添加详细信息的设置屏幕类

public class SetupScreen extends AppCompatActivity implements AdapterView.OnItemSelectedListener {

private String Name;
private String Gender;
private String Height;
private String CurrentWeight;
private String TargetWeight;
private String DOB;
private String ActivityLevel;
private String WeightDifference;

private Database dbhelper;




@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_setup_screen);
    Name = "";
    Gender = "";
    Height = "";
    CurrentWeight = "";
    TargetWeight = "";
    DOB = "";
    ActivityLevel = "";
    WeightDifference = "";


    dbhelper = new Database(getApplicationContext());





    Spinner spinnerGender = (Spinner) findViewById(R.id.spinnerGender);

    ArrayAdapter<CharSequence> adapterGender = ArrayAdapter.createFromResource(this,
            R.array.gender, android.R.layout.simple_spinner_item);
    adapterGender.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinnerGender.setAdapter(adapterGender);

    spinnerGender.setOnItemSelectedListener(this);

    Spinner spinnerActivityLevel = (Spinner) findViewById(R.id.spinnerActivityLevel);

    ArrayAdapter<CharSequence> adapterActivity = ArrayAdapter.createFromResource(this,
            R.array.activity_level, android.R.layout.simple_spinner_item);
    adapterActivity.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinnerActivityLevel.setAdapter(adapterActivity);

    spinnerActivityLevel.setOnItemSelectedListener(this);

    Spinner spinnerWeightDifference = (Spinner) findViewById(R.id.spinnerWeightDifference);

    ArrayAdapter<CharSequence> adapterWeight = ArrayAdapter.createFromResource(this,
            R.array.weight_difference, android.R.layout.simple_spinner_item);
    adapterWeight.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinnerWeightDifference.setAdapter(adapterWeight);

    spinnerWeightDifference.setOnItemSelectedListener(this);



}

public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
    Gender = parent.getItemAtPosition(position).toString();
    ActivityLevel = parent.getItemAtPosition(position).toString();
    WeightDifference = parent.getItemAtPosition(position).toString();
}

public void onNothingSelected(AdapterView<?> parent) {
    // An interface callback
}

public void save(View view) {


    Name = ((EditText)findViewById(R.id.Name)).getText().toString();
    DOB = ((EditText)findViewById(R.id.DOB)).getText().toString();
    Height = ((EditText)findViewById(R.id.Height)).getText().toString();
    CurrentWeight = ((EditText)findViewById(R.id.CurrentWeight)).getText().toString();
    TargetWeight = ((EditText)findViewById(R.id.TargetWeight)).getText().toString();


    if (Name.isEmpty()){
        Toast.makeText(getApplicationContext(), "Name cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (Gender.isEmpty()){
        Toast.makeText(getApplicationContext(), "Gender cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (DOB.isEmpty()){
        Toast.makeText(getApplicationContext(), "DOB cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (Height.isEmpty()){
        Toast.makeText(getApplicationContext(), "Height cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (CurrentWeight.isEmpty()){
        Toast.makeText(getApplicationContext(), "Current weight cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    Float CurrentWeightNum = Float.parseFloat(CurrentWeight);
    if (CurrentWeightNum < 43.0){
        Toast.makeText(getApplicationContext(), "Your current weight is not supported by this application", Toast.LENGTH_LONG).show();
        return;
    }

    if (TargetWeight.isEmpty()){
        Toast.makeText(getApplicationContext(), "Target weight cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    Float TargetWeightNum = Float.parseFloat(TargetWeight);
    if (TargetWeightNum > 93.0){
        Toast.makeText(getApplicationContext(), "Your target weight is not supported by this application", Toast.LENGTH_LONG).show();
        return;
    }
    if (ActivityLevel.isEmpty()){
        Toast.makeText(getApplicationContext(), "Activity level cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (WeightDifference.isEmpty()){
        Toast.makeText(getApplicationContext(), "Weight difference cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }

    if (CurrentWeightNum.equals(TargetWeightNum)){
        Toast.makeText(getApplicationContext(), "Current and target weight can not be the same!", Toast.LENGTH_LONG).show();
        return;
    }

    dbhelper.addUserData(Name, Gender, DOB, Height, CurrentWeightNum, TargetWeightNum, ActivityLevel, WeightDifference);

    Toast.makeText(getApplicationContext(), "You have been saved!", Toast.LENGTH_LONG).show();

    Intent intent = new Intent(this, MainActivity.class);
    startActivity(intent);


}

public class SetupScreen扩展AppCompative活动实现AdapterView.OnItemSelectedListener{
私有字符串名称；
私人字符串性别；
私有字符串高度；
私有字符串当前权重；
私有字符串目标权重；
私有字符串DOB；
私有字符串ActivityLevel；
私有字符串权重差；
专用数据库dbhelper；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u setup\u屏幕）；
Name=“”；
性别=”；
高度=”；
当前权重=”；
TargetWeight=“”；
DOB=“”；
ActivityLevel=“”；
权重差=”；
dbhelper=新数据库（getApplicationContext（））；
Spinner spinnerGender=（Spinner）findViewById（R.id.spinnerGender）；
ArrayAdapter adapterGender=ArrayAdapter.createFromResource（此，
R.array.gender，android.R.layout.simple\u spinner\u item）；
adapterGender.setDropDownViewResource（android.R.layout.simple\u微调器\u下拉菜单\u项）；
喷丝头性别：setAdapter（adapterGender）；
spinnerGender.SetonimSelectedListener（此）；
微调器spinnerActivityLevel=（微调器）findViewById（R.id.spinnerActivityLevel）；
ArrayAdapter adapterActivity=ArrayAdapter.createFromResource（此，
R.array.activity\u level、android.R.layout.simple\u微调器\u项）；
adapterActivity.setDropDownViewResource（android.R.layout.simple\u微调器\u下拉菜单\u项）；
SpinGeneraActivityLevel.setAdapter（适配器活动）；
spinnerActivityLevel.setOnItemSelectedListener（此）；
喷丝器喷丝器重量差=（喷丝器）findViewById（R.id.喷丝器重量差）；
ArrayAdapter adapterWeight=ArrayAdapter.createFromResource（此，
R.array.weight\u difference，android.R.layout.simple\u spinner\u item）；
adapterWeight.setDropDownViewResource（android.R.layout.simple\u微调器\u下拉菜单\u项）；
喷丝头重量差。设置适配器（适配器重量）；
喷丝头重量差。setOnItemSelectedListener（此）；
}
已选择公共视图（AdapterView父视图、视图视图、整型位置、长id）{
Gender=parent.getItemAtPosition（position.toString（）；
ActivityLevel=parent.getItemAtPosition（position.toString（）；
WeightDifference=parent.getItemAtPosition（position.toString（）；
}
未选择公共无效（AdapterView父级）{
//接口回调
}
公共作废保存（视图）{
Name=（（EditText）findViewById（R.id.Name））.getText（）.toString（）；
DOB=（（EditText）findViewById（R.id.DOB））.getText（）.toString（）；
高度=（（EditText）findViewById（R.id.Height））.getText（）.toString（）；
CurrentWeight=（（EditText）findViewById（R.id.CurrentWeight））.getText（）.toString（）；
TargetWeight=（（EditText）findViewById（R.id.TargetWeight））.getText（）.toString（）；
if（Name.isEmpty（））{
Toast.makeText（getApplicationContext（），“名称不能为空！”，Toast.LENGTH\u LONG.show（）；
返回；
}
if（Gender.isEmpty（））{
Toast.makeText（getApplicationContext（），“性别不能为空！”，Toast.LENGTH\u LONG.show（）；
返回；
}
if（DOB.isEmpty（））{
Toast.makeText（getApplicationContext（），“DOB不能为空！”，Toast.LENGTH\u LONG.show（）；
返回；
}
if（Height.isEmpty（））{
Toast.makeText（getApplicationContext（），“高度不能为空！”，Toast.LENGTH\u LONG.show（）；
返回；
}
if（CurrentWeight.isEmpty（））{
Toast.makeText（getApplicationContext（），“当前权重不能为空！”，Toast.LENGTH\u LONG.show（）；
返回；
}
Float CurrentWeightNum=Float.parseFloat（CurrentWeight）；
如果（CurrentWeightNum<43.0）{
Toast.makeText（getApplicationContext（），“此应用程序不支持您当前的体重”，Toast.LENGTH_LONG.show（）；
返回；
}
if（TargetWeight.isEmpty（））{
Toast.makeText（getApplicationContext（），“目标权重不能为空！”，Toast.LENGTH\u LONG.show（）；
返回；
}
Float-TargetWeightNum=Float.parseFloat（TargetWeight）；
如果（目标权重>93.0）{
Toast.makeText（getApplicationContext（），“此应用程序不支持您的目标体重”，Toast.LENGTH_LONG.show（）；
返回；
}
if（ActivityLevel.isEmpty（））{
Toast.makeText（getApplicationContext（），“活动级别不能为空！”，Toast.LENGTH\u LONG.show（）；
返回；
}
if（WeightDifference.isEmpty（））{
Toast.makeText（getApplicationContext（），“重量差不能为空！”，Toast.LENGTH\u LONG.show（）；
返回；
}
如果（CurrentWeightNum.等于（TargetWeightNum））{
Toast.makeText（getApplicationContext（），“当前和目标权重不能相同！”，Toast.LENGTH_LONG.show（）；
返回；
}
addUserData（姓名、性别、出生日期、身高、CurrentWeightNum、TargetWeightNum、ActivityLevel、权重差）；
Toast.makeText（getApplicationContext（），“您已被保存！”，Toast.LENGTH\u LONG.show（）；
意向意向=新意向（此，MainActivity.class）；
星触觉（意向）；
}

}

很抱歉，如果格式不正确，应用程序当前未打开，但是当我删除设置屏幕类中的dbhelper内容时，应用程序会运行，但当我尝试按enter键时，应用程序会崩溃，该键调用adding data方法。我已经调查过这个问题，但看不出哪里出了问题。 谢谢

删除

onCreate（this.getWritableDatabase（））来自构造函数。不需要显式地调用它

创建
数据库时调用
OnCreate（）
回调
public class SetupScreen extends AppCompatActivity implements AdapterView.OnItemSelectedListener {

private String Name;
private String Gender;
private String Height;
private String CurrentWeight;
private String TargetWeight;
private String DOB;
private String ActivityLevel;
private String WeightDifference;

private Database dbhelper;




@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_setup_screen);
    Name = "";
    Gender = "";
    Height = "";
    CurrentWeight = "";
    TargetWeight = "";
    DOB = "";
    ActivityLevel = "";
    WeightDifference = "";


    dbhelper = new Database(getApplicationContext());





    Spinner spinnerGender = (Spinner) findViewById(R.id.spinnerGender);

    ArrayAdapter<CharSequence> adapterGender = ArrayAdapter.createFromResource(this,
            R.array.gender, android.R.layout.simple_spinner_item);
    adapterGender.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinnerGender.setAdapter(adapterGender);

    spinnerGender.setOnItemSelectedListener(this);

    Spinner spinnerActivityLevel = (Spinner) findViewById(R.id.spinnerActivityLevel);

    ArrayAdapter<CharSequence> adapterActivity = ArrayAdapter.createFromResource(this,
            R.array.activity_level, android.R.layout.simple_spinner_item);
    adapterActivity.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinnerActivityLevel.setAdapter(adapterActivity);

    spinnerActivityLevel.setOnItemSelectedListener(this);

    Spinner spinnerWeightDifference = (Spinner) findViewById(R.id.spinnerWeightDifference);

    ArrayAdapter<CharSequence> adapterWeight = ArrayAdapter.createFromResource(this,
            R.array.weight_difference, android.R.layout.simple_spinner_item);
    adapterWeight.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinnerWeightDifference.setAdapter(adapterWeight);

    spinnerWeightDifference.setOnItemSelectedListener(this);



}

public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
    Gender = parent.getItemAtPosition(position).toString();
    ActivityLevel = parent.getItemAtPosition(position).toString();
    WeightDifference = parent.getItemAtPosition(position).toString();
}

public void onNothingSelected(AdapterView<?> parent) {
    // An interface callback
}

public void save(View view) {


    Name = ((EditText)findViewById(R.id.Name)).getText().toString();
    DOB = ((EditText)findViewById(R.id.DOB)).getText().toString();
    Height = ((EditText)findViewById(R.id.Height)).getText().toString();
    CurrentWeight = ((EditText)findViewById(R.id.CurrentWeight)).getText().toString();
    TargetWeight = ((EditText)findViewById(R.id.TargetWeight)).getText().toString();


    if (Name.isEmpty()){
        Toast.makeText(getApplicationContext(), "Name cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (Gender.isEmpty()){
        Toast.makeText(getApplicationContext(), "Gender cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (DOB.isEmpty()){
        Toast.makeText(getApplicationContext(), "DOB cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (Height.isEmpty()){
        Toast.makeText(getApplicationContext(), "Height cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (CurrentWeight.isEmpty()){
        Toast.makeText(getApplicationContext(), "Current weight cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    Float CurrentWeightNum = Float.parseFloat(CurrentWeight);
    if (CurrentWeightNum < 43.0){
        Toast.makeText(getApplicationContext(), "Your current weight is not supported by this application", Toast.LENGTH_LONG).show();
        return;
    }

    if (TargetWeight.isEmpty()){
        Toast.makeText(getApplicationContext(), "Target weight cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    Float TargetWeightNum = Float.parseFloat(TargetWeight);
    if (TargetWeightNum > 93.0){
        Toast.makeText(getApplicationContext(), "Your target weight is not supported by this application", Toast.LENGTH_LONG).show();
        return;
    }
    if (ActivityLevel.isEmpty()){
        Toast.makeText(getApplicationContext(), "Activity level cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }
    if (WeightDifference.isEmpty()){
        Toast.makeText(getApplicationContext(), "Weight difference cannot be empty!", Toast.LENGTH_LONG).show();
        return;
    }

    if (CurrentWeightNum.equals(TargetWeightNum)){
        Toast.makeText(getApplicationContext(), "Current and target weight can not be the same!", Toast.LENGTH_LONG).show();
        return;
    }

    dbhelper.addUserData(Name, Gender, DOB, Height, CurrentWeightNum, TargetWeightNum, ActivityLevel, WeightDifference);

    Toast.makeText(getApplicationContext(), "You have been saved!", Toast.LENGTH_LONG).show();

    Intent intent = new Intent(this, MainActivity.class);
    startActivity(intent);


}

public void onCreate(SQLiteDatabase db) {
    db.execSQL(SQL_CREATE_USER);
    db.close(); // remove this line
}

onCreate(this.getWritableDatabase());

db.execSQL("DROP TABLE IF EXISTS " + YOUR_TABLE_NAME);
onCreate(db);