android数据库程序出错
我的类调用数据库android数据库程序出错,android,database,eclipse,sqlite,Android,Database,Eclipse,Sqlite,我的类调用数据库 06-29 01:24:15.882: ERROR/AndroidRuntime(747): Uncaught handler: thread main exiting due to uncaught exception 06-29 01:24:15.922: ERROR/AndroidRuntime(747): java.lang.RuntimeException: Unable to start activity ComponentInfo{one.two/one.two.
06-29 01:24:15.882: ERROR/AndroidRuntime(747): Uncaught handler: thread main exiting due to uncaught exception
06-29 01:24:15.922: ERROR/AndroidRuntime(747): java.lang.RuntimeException: Unable to start activity ComponentInfo{one.two/one.two.Arrival}: java.lang.NullPointerException
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2268)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2284)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at android.app.ActivityThread.access$1800(ActivityThread.java:112)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1692)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at android.os.Handler.dispatchMessage(Handler.java:99)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at android.os.Looper.loop(Looper.java:123)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at android.app.ActivityThread.main(ActivityThread.java:3948)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at java.lang.reflect.Method.invokeNative(Native Method)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at java.lang.reflect.Method.invoke(Method.java:521)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at dalvik.system.NativeStart.main(Native Method)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): Caused by: java.lang.NullPointerException
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at one.two.DBAdapter.getAllTitles(DBAdapter.java:167)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at one.two.Arrival.getData(Arrival.java:35)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at one.two.Arrival.onCreate(Arrival.java:21)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2231)
06-29 01:24:15.922: ERROR/AndroidRuntime(747): ... 11 more
packageone.two；
导入java.util.ArrayList；
导入java.util.List；
导入android.app.ListActivity；
导入android.os.Bundle；
导入android.widget.ArrayAdapter；
导入android.widget.ListView；
公共类到达扩展ListActivity
{
私有列表视图列表视图；
DBAdapter db=新的DBAdapter（此）；
/**在首次创建活动时调用*/
创建时的公共void（Bundle savedInstanceState）
{
super.onCreate（savedInstanceState）；
setContentView（R.layout.main）；
getData（）；
//db.open（）；
listView=（listView）findViewById（android.R.id.list）；
//db.close（）；
}
私有void getData（）
{
//显示要打开数据库的一些显示
db.open（）；
//显示您已打开的一些显示
//冗余请参见下面的语句----List items=new ArrayList（）；
//调用DBAdapter方法获取所有标题（）
List items=DBAdapter.getAllTitles（）；
//通过display语句或show逐个遍历项目
//关于布局
//检查一下怎么做
ArrayAdapter titles=新的ArrayAdapter（此，
R.布局图、主要项目）；
db.close（）；
}
}
package one.two;
import java.util.ArrayList;
import java.util.List;
import android.app.ListActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class Arrival extends ListActivity
{
private ListView listView;
DBAdapter db = new DBAdapter(this);
/** Called when the activity is first created. */
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
getData();
// db.open();
listView = (ListView) findViewById(android.R.id.list);
// db.close();
}
private void getData()
{
// show some display that you are going to open db
db.open();
// show some display that you have opened
// redundant see below statement ---- List<String> items = new ArrayList<String>();
// call the DBAdapter method to getAllTitles()
List<String> items = DBAdapter.getAllTitles();
// iterate through the items one by one thru display statement or show
// on layout
// check how to do that
ArrayAdapter<String> titles = new ArrayAdapter<String>(this,
R.layout.main, items);
db.close();
}
}
packageone.two；
导入java.io.FileOutputStream；
导入java.io.IOException；
导入java.io.InputStream；
导入java.io.OutputStream；
导入java.util.List；
导入android.app.ListActivity；
导入android.content.Context；
导入android.database.Cursor；
导入android.database.SQLException；
导入android.database.sqlite.SQLiteDatabase；
导入android.database.sqlite.SQLiteException；
导入android.database.sqlite.SQLiteOpenHelper；
导入android.util.Log；
导入java.util.ArrayList；
公共类DBAdapter扩展了ListActivity
{
私有静态字符串DB_PATH=“/data/data/one.two/databases/”；
私有静态最终字符串数据库\u NAME=“ferry.db”；
私有静态最终字符串数据库\u TABLE=“port”；
公共静态语境；
公共字符串status=“status”；
公共字符串id=“id”；
公共字符串arrival=“arrival”；
公共字符串destination=“destination”；
公共字符串ferry=“ferry”；
//空构造函数
公共数据库适配器（）
{
}
//重载非空构造函数
公共DBAdapter（上下文）
{
}
公共类DatabaseHelper扩展了SQLiteOpenHelper
{
语境；
DatabaseHelper（上下文）
{
super（上下文、数据库名称、null、数据库版本）；
this.context=上下文；
}//结束构造函数DatabaseHelper
@凌驾
public void onUpgrade（SQLiteDatabase db，int oldVersion，
int（新版本）
{
}//(完)
@凌驾
public void onCreate（SQLiteDatabase db）
{
布尔值dbExist=checkDatabase（）；
if（dbExist）
{
}
其他的
{
这是.getReadableDatabase（）；
尝试
{
copyDataBase（）；
}
捕获（IOE异常）
{
抛出新错误（“复制数据库时出错”）；
}
}
}//结束onCreate（）
}//端类数据库助手
私有静态数据库助手DBHelper；
私有静态数据库；
私有静态最终int数据库_VERSION=1；
////提出的背景/////////////
//私人最终语境；
私有布尔校验数据库（）
{
SQLiteDatabase checkDB=null；
尝试
{
字符串myPath=DB_路径+数据库_名称；
checkDB=SQLiteDatabase.openDatabase（myPath，null，
SQLiteDatabase.OPEN_READONLY）；
}
catch（sqlitee异常）
{
//数据库还不存在
}
if（checkDB！=null）
{
checkDB.close（）；
}
return checkDB！=null？true:false；
}//结束检查数据库（）
私有void copyDataBase（）引发IOException
{
//打开本地数据库作为输入流
InputStream myInput=context.getAssets（）.open（数据库名称）；
//刚创建的空数据库的路径
字符串outFileName=DB\u路径+数据库\u名称；
//打开空数据库作为输出流
OutputStream myOutput=新文件OutputStream（outFileName）；
//将字节从输入文件传输到输出文件
字节[]缓冲区=新字节[1024]；
整数长度；
而（（长度=myInput.read（缓冲区））>0）
{
写入（缓冲区，0，长度）；
}
//关闭溪流
myOutput.flush（）；
myOutput.close（）；
myInput.close（）；
}//结束复制数据库（）
public void DBAdapter（）引发SQLException
{
字符串myPath=DB_路径+数据库_名称；
db=SQLiteDatabase.openDatabase（myPath，null，
SQLiteDatabase.OPEN_READONLY）；
}//结束DBAdapter（）
公开作废
{
//打开数据库
字符串myPath=DB_路径+数据库_名称；
db=SQLiteDatabase.openDatabase（myPath，null，SQLiteDatabase.OPEN\u READONLY）；
}
//---关闭数据库---
公众假期结束（）
{
DBHelper.close（）；
}//结束结束（）
公共静态列表getAllTitles（）
{
列表标题=新的ArrayList（）；
光标c=null；
c=db.query（“端口”，
新字符串[]{“状态”、“id”、“到达”，
“目的地”，“渡轮”}，null，null，
package one.two;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;
import android.app.ListActivity;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import java.util.ArrayList;
public class DBAdapter extends ListActivity
{
private static String DB_PATH = "/data/data/one.two/databases/";
private static final String DATABASE_NAME = "ferry.db";
private static final String DATABASE_TABLE = "port";
public static Context context;
public String status = "status";
public String id = "id";
public String arrival = "arrival";
public String destination = "destination";
public String ferry = "ferry";
//null constructor
public DBAdapter()
{
}
//overloaded non-null constructor
public DBAdapter(Context context)
{
}
public class DatabaseHelper extends SQLiteOpenHelper
{
Context context;
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
}//end constructor DatabaseHelper
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion,
int newVersion)
{
}//end onUpgrade()
@Override
public void onCreate(SQLiteDatabase db)
{
boolean dbExist = checkDatabase();
if (dbExist)
{
}
else
{
this.getReadableDatabase();
try
{
copyDataBase();
}
catch (IOException e)
{
throw new Error("Error copying database");
}
}
}//end onCreate()
}// end class DatabaseHelper
private static DatabaseHelper DBHelper;
private static SQLiteDatabase db;
private static final int DATABASE_VERSION = 1;
//// context brought up /////////////
//private final Context context;
private boolean checkDatabase()
{
SQLiteDatabase checkDB = null;
try
{
String myPath = DB_PATH + DATABASE_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}
catch (SQLiteException e)
{
// database doesn't exist yet
}
if (checkDB != null)
{
checkDB.close();
}
return checkDB != null ? true : false;
}//end checkDatabase()
private void copyDataBase() throws IOException
{
// Open your local db as the input stream
InputStream myInput = context.getAssets().open(DATABASE_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DATABASE_NAME;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0)
{
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}//end copyDataBase()
public void DBAdapter() throws SQLException
{
String myPath = DB_PATH + DATABASE_NAME;
db = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}//end DBAdapter()
public void open()
{
//Open the database
String myPath = DB_PATH + DATABASE_NAME;
db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
// ---closes the database---
public void close()
{
DBHelper.close();
}//end close()
public static List<String> getAllTitles()
{
List<String> titles = new ArrayList<String>();
Cursor c=null;
c = db.query("port",
new String[] { "status", "id", "arrival",
"destination", "ferry" }, null, null,
null, null, null);
try {
if (c!=null) {
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext())
{
DBAdapter title = new DBAdapter(context);
title.status = c.getString(0);
title.id = c.getString(1);
title.arrival = c.getString(2);
title.destination = c.getString(3);
title.ferry = c.getString(4);
}
}
} finally {
if (c!=null) {
c.close();
}
}
return titles;
}//end getAllTitles()
}//end class DBAdapter
package one.two;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;
import android.app.ListActivity;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import java.util.ArrayList;
public class DBAdapter extends ListActivity
{
private static String DB_PATH = "/data/data/one.two/databases/";
private static final String DATABASE_NAME = "ferry.db";
private static final String DATABASE_TABLE = "port";
public static Context context;
public String status = "status";
public String id = "id";
public String arrival = "arrival";
public String destination = "destination";
public String ferry = "ferry";
//null constructor
public DBAdapter()
{
}
//overloaded non-null constructor
public DBAdapter(Context context)
{
}
public class DatabaseHelper extends SQLiteOpenHelper
{
Context context;
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
}//end constructor DatabaseHelper
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion,
int newVersion)
{
}//end onUpgrade()
@Override
public void onCreate(SQLiteDatabase db)
{
boolean dbExist = checkDatabase();
if (dbExist)
{
}
else
{
this.getReadableDatabase();
try
{
copyDataBase();
}
catch (IOException e)
{
throw new Error("Error copying database");
}
}
}//end onCreate()
}// end class DatabaseHelper
private static DatabaseHelper DBHelper;
private static SQLiteDatabase db;
private static final int DATABASE_VERSION = 1;
//// context brought up /////////////
//private final Context context;
private boolean checkDatabase()
{
SQLiteDatabase checkDB = null;
try
{
String myPath = DB_PATH + DATABASE_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}
catch (SQLiteException e)
{
// database doesn't exist yet
}
if (checkDB != null)
{
checkDB.close();
}
return checkDB != null ? true : false;
}//end checkDatabase()
private void copyDataBase() throws IOException
{
// Open your local db as the input stream
InputStream myInput = context.getAssets().open(DATABASE_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DATABASE_NAME;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0)
{
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}//end copyDataBase()
public void DBAdapter() throws SQLException
{
String myPath = DB_PATH + DATABASE_NAME;
db = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}//end DBAdapter()
public void open()
{
//Open the database
String myPath = DB_PATH + DATABASE_NAME;
db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
// ---closes the database---
public void close()
{
DBHelper.close();
}//end close()
public List<String> getAllTitles()
{
List<String> titles = new ArrayList<String>();
Cursor c=null;
c = db.query("port",
new String[] { "status", "id", "arrival",
"destination", "ferry" }, null, null,
null, null, null);
try {
if (c!=null) {
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext())
{
DBAdapter title = new DBAdapter(context);
title.status = c.getString(0);
title.id = c.getString(1);
title.arrival = c.getString(2);
title.destination = c.getString(3);
title.ferry = c.getString(4);
}
}
} finally {
if (c!=null) {
c.close();
}
}
return titles;
}//end getAllTitles()
}//end class DBAdapter
package one.two;
import java.util.ArrayList;
import java.util.List;
import android.app.ListActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class Arrival extends ListActivity
{
private ListView listView;
DBAdapter db = new DBAdapter(this);
/** Called when the activity is first created. */
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
getData();
// db.open();
listView = (ListView) findViewById(android.R.id.list);
// db.close();
}
private void getData()
{
// show some display that you are going to open db
db.open();
// show some display that you have opened
// redundant see below statement ---- List<String> items = new ArrayList<String>();
// call the DBAdapter method to getAllTitles()
List<String> items = db.getAllTitles();
// iterate through the items one by one thru display statement or show
// on layout
// check how to do that
ArrayAdapter<String> titles = new ArrayAdapter<String>(this,
R.layout.main, items);
db.close();
}
}