例外の原因となるメソッドはinsertdetails()
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私のコード:
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
public class AllLevels extends Activity implements OnClickListener {
ImageView iv1, iv2, iv3, iv4, iv5, iv6, iv7, iv8, iv9, iv10, iv11, iv12;
TextView tv;
MediaPlayer mp;
DBAdapter dbAdapter;
DBHelper dbHelper;
SQLiteDatabase db;
long a;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_all_levels);
mp = MediaPlayer.create(this, R.raw.main);
mp.start();
mp.setLooping(true);
Context context = this;
final SharedPrefsHandler spf = new SharedPrefsHandler(context);
int i = spf.loadPrefs();
Toast.makeText(this, "Value from sharedpref"+i, Toast.LENGTH_SHORT).show();
//creating database and entering default values
dbHelper = new DBHelper(this);
dbHelper.getWritableDatabase(); //Works fine till here, even database is generated.
//ここで問題があると思われます。これらの行を削除するとコードが実行され、これらの行が含まれているとデータベースが生成されません。
dbAdapter.insertDetails(1, 1, 0, 0);
dbAdapter.insertDetails(2, 2, 0, 0);
dbAdapter.insertDetails(3, 3, 0, 0);
dbAdapter.insertDetails(4, 4, 0, 0);
dbAdapter.insertDetails(5, 5, 0, 0);
dbAdapter.insertDetails(6, 6, 0, 0);
dbAdapter.insertDetails(7, 7, 0, 0);
dbAdapter.insertDetails(8, 8, 0, 0);
dbAdapter.insertDetails(9, 9, 0, 0);
dbAdapter.insertDetails(10, 10, 0, 0);
dbAdapter.insertDetails(11, 11, 0, 0);
dbAdapter.insertDetails(12, 12, 0, 0);
}
package com.s.wrestlernicknames;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
public class DBAdapter {
SQLiteDatabase db;
DBHelper dbHelper;
Context context;
public DBAdapter(Context c) {
this.context = c;
}
public DBAdapter openToRead() {
dbHelper = new DBHelper(context);
db = dbHelper.getReadableDatabase();
return this;
}
public DBAdapter openToWrite() {
dbHelper = new DBHelper(context);
db = dbHelper.getWritableDatabase();
return this;
}
public void close() {
db.close();
}
public long insertDetails(int id, int level, int totalTime, int score) {//Function that is being called to insert the values.
ContentValues contentValues = new ContentValues();
contentValues.put(DBHelper.C_ID, id);
contentValues.put(DBHelper.LEVEL, level);
contentValues.put(DBHelper.TIME, totalTime);
contentValues.put(DBHelper.SCORE, score);
openToWrite();
long val = db.insert(DBHelper.TABLE_NAME, null, contentValues);
close();
return val;
}
public Cursor queryName() {
String[] column = {DBHelper.C_ID, DBHelper.LEVEL, DBHelper.TIME, DBHelper.SCORE};
openToWrite();
Cursor cursor = db.query(DBHelper.TABLE_NAME, column, null, null, null, null, null);
return cursor;
}
public long updateDetails(int id, int level, int totalTime, int score) {
ContentValues contentValues = new ContentValues();
contentValues.put(DBHelper.C_ID, id);
contentValues.put(DBHelper.LEVEL, level);
contentValues.put(DBHelper.TIME, totalTime);
contentValues.put(DBHelper.SCORE, score);
openToWrite();
long val = db.update(DBHelper.TABLE_NAME, contentValues, DBHelper.C_ID+"="+id, null);
close();
return val;
}
}
データベースを生成するクラス:
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DBHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME = "data";
public static final String TABLE_NAME = "score_table";
public static final String C_ID = "_id";
public static final String LEVEL = "level";
public static final String SCORE = "score";
public static final String TIME = "time";
public static final int VERSION = 1;
private final String createDB = "create table if not exists "+ TABLE_NAME + "("
+ C_ID + " integer primary key, "
+ LEVEL + " integer, "
+ SCORE + " integer, "
+ TIME + " integer ); ";
public DBHelper(Context context) {
super(context, DATABASE_NAME, null, VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(createDB);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("drop table "+ TABLE_NAME);
}
}
スタックトレース:
07-01 01:01:28.429: E/AndroidRuntime(1193): FATAL EXCEPTION: main
07-01 01:01:28.429: E/AndroidRuntime(1193): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.s.wrestlernicknames/com.s.wrestlernicknames.AllLevels}: java.lang.NullPointerException
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1955)
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980)
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.app.ActivityThread.access$600(ActivityThread.java:122)
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146)
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.os.Handler.dispatchMessage(Handler.java:99)
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.os.Looper.loop(Looper.java:137)
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.app.ActivityThread.main(ActivityThread.java:4340)
07-01 01:01:28.429: E/AndroidRuntime(1193): at java.lang.reflect.Method.invokeNative(Native Method)
07-01 01:01:28.429: E/AndroidRuntime(1193): at java.lang.reflect.Method.invoke(Method.java:511)
07-01 01:01:28.429: E/AndroidRuntime(1193): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
07-01 01:01:28.429: E/AndroidRuntime(1193): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
07-01 01:01:28.429: E/AndroidRuntime(1193): at dalvik.system.NativeStart.main(Native Method)
07-01 01:01:28.429: E/AndroidRuntime(1193): Caused by: java.lang.NullPointerException
07-01 01:01:28.429: E/AndroidRuntime(1193): at com.s.wrestlernicknames.AllLevels.onCreate(AllLevels.java:53)
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.app.Activity.performCreate(Activity.java:4465)
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
07-01 01:01:28.429: E/AndroidRuntime(1193): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1919)
07-01 01:01:28.429: E/AndroidRuntime(1193): ... 11 more
07-01 01:01:31.259: I/Process(1193): Sending signal. PID: 1193 SIG: 9
close() ステートメント、構文、構造化など、多くのことを確認しました。助けていただければ幸いです。私はいくつかの基本的なエラーを犯していることを知っていますが、見つけることができませんでした。