Eclipse ADT Android sqlite：应用程序在打开后立即崩溃

Question

Hello I am programming a database that a user is able to view that contains information about data that I am populating the database with. When running the activity on my phone or emulator the application crashes. There are no logcat issues so I am unsure as to what could be the issue. If anyone could provide me with any tips I would greatly appreciate it since I am new to programming in java and using android ADT. Below is all of the code I have for my activities. The current version I'm using is Build: v21.1.0-569685

Main Activity where the database is created:

package com.example.database;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class MainActivity 
{
    public static final String KEY_ROWID = "_id";
    public static final String KEY_BUSINESS = "business";
    public static final String KEY_ADDRESS = "address";
    public static final String KEY_PHONE = "phone";
    public static final String KEY_HOURS = "hours";
    public static final String KEY_WEB = "website";
    public static final String KEY_TYPE = "type";

    private static final String TAG = "MainActivity";

    private static final String DATABASE_NAME = "BloomBusiness";
    private static final String DATABASE_TABLE = "Business";
    private static final int DATABASE_VERSION = 1;

    private static final String DATABASE_CREATE =
        "create table Business (_id integer primary key autoincrement, "
        +"business text not null, address text not null, hours text not null"+"web text not null"+"type text not null" 
        + "phone text not null);";

    private final Context context; 

    private DatabaseHelper DBHelper;
    private SQLiteDatabase db;

    public MainActivity(Context ctx) 
    {
        this.context = ctx;
        DBHelper = new DatabaseHelper(context);
    }

    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) 
        {
            Log.w(TAG, "Upgrading database from version " + oldVersion 
                    + " to "
                    + newVersion + ", which will destroy all old data");
            db.execSQL("DROP TABLE IF EXISTS Business");
            onCreate(db);
        }
    }    

    //---opens the database---
    public MainActivity open() throws SQLException 
    {
        db = DBHelper.getWritableDatabase();
        return this;
    }

    //---closes the database---    
    public void close() 
    {
        DBHelper.close();
    }

    //---insert a title into the database---
    public long insertTitle(String business, String address, String phone, String hours, String website, String type) 
    {
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_BUSINESS, business);
        initialValues.put(KEY_ADDRESS, address);
        initialValues.put(KEY_PHONE, phone);
        initialValues.put(KEY_HOURS, hours);
        initialValues.put(KEY_WEB, website);
        initialValues.put(KEY_TYPE, type);

        return db.insert(DATABASE_TABLE, null, initialValues);
    }

    //---deletes a particular title---
    public boolean deleteTitle(long rowId) 
    {
        return db.delete(DATABASE_TABLE, KEY_ROWID + 
                "=" + rowId, null) > 0;
    }

    //---retrieves all the titles---
    public Cursor getAllTitles() 
    {
        return db.query(DATABASE_TABLE, new String[] {
                KEY_ROWID, 
                KEY_BUSINESS,
                KEY_ADDRESS,
                KEY_PHONE,
                KEY_HOURS,
                KEY_WEB,
                KEY_TYPE}, 
                null, 
                null, 
                null, 
                null, 
                null);
    }

    //---retrieves a particular title---
    public Cursor getTitle(long rowId) throws SQLException 
    {
        Cursor mCursor =
                db.query(DATABASE_TABLE, new String[] {
                        KEY_ROWID,
                        KEY_BUSINESS, 
                        KEY_ADDRESS,
                        KEY_PHONE,
                        KEY_HOURS,
                        KEY_WEB,
                        KEY_TYPE}, 
                        KEY_ROWID + "=" + rowId, 
                        null,
                        null, 
                        null, 
                        null, 
                        null);
        if (mCursor != null) {
            mCursor.moveToFirst();
        }
        return mCursor;
    }

    //---updates a title---
    public boolean updateTitle(long rowId, String business, 
    String address, String phone, String hours, String website,String type) 
    {
        ContentValues args = new ContentValues();
        args.put(KEY_BUSINESS, business);
        args.put(KEY_ADDRESS, address);
        args.put(KEY_PHONE, phone);
        args.put(KEY_HOURS,hours);
        args.put(KEY_WEB, website);
        args.put(KEY_TYPE, type);
        return db.update(DATABASE_TABLE, args, 
                         KEY_ROWID + "=" + rowId, null) > 0;
    }
}

Returning a list of all of the business names:

package com.example.database;

import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.widget.Toast;

public class DBUse extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        MainActivity db = new MainActivity(this);


        db.open();
        Cursor c = db.getAllTitles();
        if(c.moveToFirst())
        {
            do{DisplayTitle(c);
        }while (c.moveToNext());
    }   
        db.open();
        Cursor b = db.getTitle(1);

        if (b.moveToFirst())
            DisplayTitle(c);
        else
            Toast.makeText(this,"No business found",Toast.LENGTH_LONG).show();
        db.close();
    db.close();


}

    public void DisplayTitle(Cursor c) {
        Toast.makeText(this,
        "Name: " + c.getString(1)+"\n"+
        "Address:" + c.getString(2)+"\n"+
        "Phone:" + c.getString(3)+"\n"+
        "Hours:" + c.getString(4)+"\n",
        Toast.LENGTH_LONG).show();
    }


    }

Entering the data into the database:

package com.example.database;

import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.widget.Toast;

public class DBUse extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        MainActivity db = new MainActivity(this);


        db.open();
        Cursor c = db.getAllTitles();
        if(c.moveToFirst())
        {
            do{DisplayTitle(c);
        }while (c.moveToNext());
    }   
        db.open();
        Cursor b = db.getTitle(1);

        if (b.moveToFirst())
            DisplayTitle(c);
        else
            Toast.makeText(this,"No business found",Toast.LENGTH_LONG).show();
        db.close();
    db.close();


}

    public void DisplayTitle(Cursor c) {
        Toast.makeText(this,
        "Name: " + c.getString(1)+"\n"+
        "Address:" + c.getString(2)+"\n"+
        "Phone:" + c.getString(3)+"\n"+
        "Hours:" + c.getString(4)+"\n",
        Toast.LENGTH_LONG).show();
    }


    }

Lastly the manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.database"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" 
        android:debuggable="true">
        <activity
            android:name="com.example.database.DBUse"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

After changing the manifest I received this error in my console but nothing shows up in logcat.

[2013-04-10 23:46:43 - database] Performing com.example.database.MainActivity activity launch
[2013-04-10 23:46:47 - database] Application already deployed. No need to reinstall.
[2013-04-10 23:46:47 - database] Starting activity com.example.database.MainActivity on device 0A3BB5F106008016
[2013-04-10 23:46:48 - database] New package not yet registered with the system. Waiting 3 seconds before next attempt.
[2013-04-10 23:46:51 - database] Starting activity com.example.database.MainActivity on device 0A3BB5F106008016
[2013-04-10 23:46:51 - database] New package not yet registered with the system. Waiting 3 seconds before next attempt.
[2013-04-10 23:46:54 - database] Starting activity com.example.database.MainActivity on device 0A3BB5F106008016
[2013-04-10 23:46:54 - database] New package not yet registered with the system. Waiting 3 seconds before next attempt.
[2013-04-10 23:46:57 - database] Starting activity com.example.database.MainActivity on device 0A3BB5F106008016
[2013-04-10 23:46:58 - database] New package not yet registered with the system. Waiting 3 seconds before next attempt.
[2013-04-10 23:47:01 - database] Starting activity com.example.database.MainActivity on device 0A3BB5F106008016
[2013-04-10 23:47:01 - database] ActivityManager: Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.example.database/.MainActivity }
[2013-04-10 23:47:01 - database] ActivityManager: Error type 3
[2013-04-10 23:47:01 - database] ActivityManager: Error: Activity class {com.example.database/com.example.database.MainActivity} does not exist.

Answer 1

Should change your manifest to

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" 
    android:debuggable="true">
    <activity
        android:name="com.example.database.DBUse"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

MainActivity does not extends Activity, should call it DbAdapter.