我在创建第一个Android应用程序时在logcat上收到此错误。 02-28 11:07:49.547: W/dalvikvm(16532): threadid=1: thread exiting with uncaught exception (group=0x40015560)我真的迷失了，无法找到错误的位置。这是我的活动。
public class Database extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
String destPath = "/data/data/" + getPackageName()
+ "/databases/grammer";
File f = new File(destPath);
if (!f.exists()) {
CopyDB(getBaseContext().getAssets().open("grammer"),
new FileOutputStream(destPath));
Toast.makeText(Database.this, "File exists", Toast.LENGTH_SHORT)
.show();
}
}
catch (FileNotFoundException e) {
e.printStackTrace();
Toast.makeText(Database.this, "Error File", Toast.LENGTH_SHORT)
.show();
}
catch (IOException e1) {
e1.printStackTrace();
Toast.makeText(Database.this, "Error IO", Toast.LENGTH_SHORT)
.show();
}
DatabaseHandler db = new DatabaseHandler(this);
Cursor cursor = db.getAllQuestions();
if (cursor.moveToFirst())
{
do {
DisplayRecord(cursor);
}
while(cursor.moveToNext());
}
db.close();
}
public void CopyDB(InputStream inputstream, OutputStream outputstream)
throws IOException {
byte[] buffer = new byte[1024];
int length;
while ((length = inputstream.read(buffer))>0){
outputstream.write(buffer, 0, length);
}
inputstream.close();
outputstream.close();
}
public void DisplayRecord(Cursor cursor){
Toast.makeText(this,
"id:" + cursor.getString(0) + "\n" +
"Title:" + cursor.getString(8) + "\n" +
"Question:" + cursor.getString(1) + "\n" +
"Answer1:" + cursor.getString(2) + "\n" +
"Answer2:" + cursor.getString(3) + "\n" +
"Answer3:" + cursor.getString(4) + "\n" +
"Answer4:" + cursor.getString(5) + "\n" +
"Answer:" + cursor.getString(6) + "\n" +
"Answer Text:" + cursor.getString(7),
Toast.LENGTH_SHORT).show();
}
}
这是数据库处理程序类： -
public class DatabaseHandler extends SQLiteOpenHelper {
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "grammer";
// Contacts table name
private static final String TABLE_QUESTIONS = "questions";
// Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "questions";
private static final String KEY_TITLE = "question_title";
public static final String KEY_ANSWER1 = "answer1";
public static final String KEY_ANSWER2 = "answer2";
public static final String KEY_ANSWER3 = "answer3";
public static final String KEY_ANSWER4 = "answer4";
public static final String KEY_ANSWER = "answer";
public static final String KEY_ANSWER_TEXT = "answer_text";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
// will not need. if needed will have to modify adding the question title and answer text fields
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_TABLE = "CREATE TABLE " + TABLE_QUESTIONS + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
+ KEY_ANSWER1 + " TEXT," + KEY_ANSWER2 + " TEXT," + KEY_ANSWER3 + " TEXT,"
+ KEY_ANSWER4 + " TEXT," + KEY_ANSWER + " TEXT," + KEY_TITLE + " TEXT," + KEY_ANSWER_TEXT + " TEXT," +")";
db.execSQL(CREATE_TABLE);
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_QUESTIONS);
// Create tables again
onCreate(db);
}
/**
* All CRUD(Create, Read, Update, Delete) Operations
* @return
*/
// Adding new contact
long addQuestion(String Question, String Answer1, String Answer2, String Answer3, String Answer4, String Answer, String Answer_Text, String Question_Title ) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, Question); // question Name
values.put(KEY_ANSWER1, Answer1); // answer
values.put(KEY_ANSWER2, Answer2); // answer
values.put(KEY_ANSWER3, Answer3); // answer
values.put(KEY_ANSWER4, Answer4); // answer
values.put(KEY_ANSWER, Answer); // answer
values.put(KEY_ANSWER_TEXT, Answer_Text);
values.put(KEY_TITLE, Question_Title);
}
addtodb getQuestion(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_QUESTIONS, new String[] { KEY_ID,
KEY_NAME, KEY_ANSWER1, KEY_ANSWER2, KEY_ANSWER3, KEY_ANSWER4, KEY_ANSWER, KEY_ANSWER_TEXT, KEY_TITLE }, KEY_ID + "=?",
new String[] { String.valueOf(id) }, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
addtodb question = new addtodb(Integer.parseInt(cursor.getString(0)),
cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4), cursor.getString(5), cursor.getString(6), cursor.getString(7), cursor.getString(8));
return question;
}
public Cursor getAllQuestions() {
List<addtodb> QuestionList = new ArrayList<addtodb>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_QUESTIONS;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
addtodb question = new addtodb();
question.setID(Integer.parseInt(cursor.getString(0)));
question.setName(cursor.getString(1));
question.setAnswer1(cursor.getString(2));
question.setAnswer2(cursor.getString(3));
question.setAnswer3(cursor.getString(4));
question.setAnswer4(cursor.getString(5));
question.setAnswer(cursor.getString(6));
question.setAnswerText(cursor.getString(7));
question.setTitle(cursor.getString(8));
// Adding contact to list
QuestionList.add(question);
} while (cursor.moveToNext());
}
//System.out.print("Hello");
// return contact list
return cursor;
//return QuestionList; to get the questions as a list
}
// Updating single contact
public int updateQuestion(addtodb question) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, question.getName());
values.put(KEY_ANSWER, question.getAnswer1());
values.put(KEY_ANSWER, question.getAnswer2());
values.put(KEY_ANSWER, question.getAnswer3());
values.put(KEY_ANSWER, question.getAnswer4());
values.put(KEY_ANSWER, question.getAnswer());
values.put(KEY_ANSWER_TEXT, question.getAnswerText());
values.put(KEY_TITLE, question.getTitle());
// updating row
return db.update(TABLE_QUESTIONS, values, KEY_ID + " = ?",
new String[] { String.valueOf(question.getID()) });
}
// Deleting single contact
public void deleteContact(addtodb question) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_QUESTIONS, KEY_ID + " = ?",
new String[] { String.valueOf(question.getID()) });
db.close();
}
// Getting contacts Count
public int getContactsCount() {
String countQuery = "SELECT * FROM " + TABLE_QUESTIONS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
cursor.close();
// return count
return cursor.getCount();
}
}
我无法找到问题所在。
答案 0 :(得分：3)
在您的代码中会产生问题甚至可能是异常的一个问题是：
+ KEY_TITLE + " TEXT," + KEY_ANSWER_TEXT + " TEXT," +")";
^ ----- remove this ,
你不应该在'）'之前有分号，否则你的表将不会被创建
答案 1 :(得分：2)
首先使用此
更正您的Create Table Query
String CREATE_TABLE = "CREATE TABLE " + TABLE_QUESTIONS + "("
+ KEY_ID + " INTEGER PRIMARY KEY, " + KEY_NAME + " TEXT,"
+ KEY_ANSWER1 + " TEXT, " + KEY_ANSWER2 + " TEXT, " + KEY_ANSWER3 + " TEXT, "
+ KEY_ANSWER4 + " TEXT, " + KEY_ANSWER + " TEXT, " + KEY_TITLE + " TEXT, " + KEY_ANSWER_TEXT + " TEXT" +")";