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我正在开发一个在线应用程序项目。我的应用程序正常工作，但有时应用程序崩溃，并显示logcat数据库池异常，当我试图从服务器获取数据并调用我的sqlite数据库函数（并非所有的时间，它发生了很少的时间）。有关于stackoverflow中android数据库池异常的答案。大部分答案都是这样的“删除所有db.close”。现在使用这种方法后，我的应用崩溃了。但问题仍然存在。请检查我的数据库代码，并让我知道如果你发现任何问题。提前致谢。对不起，英文不好。在Android中获取Sqlite数据库调查异常
package com.example.helper;
import java.util.HashMap;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class SQLiteHandler extends SQLiteOpenHelper {
private static final String TAG = SQLiteHandler.class.getSimpleName();
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "android_api";
// Login table name
private static final String TABLE_LOGIN = "login";
// Login Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_EMAIL = "email";
private static final String KEY_CREATED_AT = "created_at";
public SQLiteHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_LOGIN_TABLE = "CREATE TABLE " + TABLE_LOGIN + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
+ KEY_EMAIL + " TEXT UNIQUE,"
+ KEY_CREATED_AT + " TEXT" + ")";
db.execSQL(CREATE_LOGIN_TABLE);
Log.d(TAG, "Database tables created");
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LOGIN);
// Create tables again
onCreate(db);
}
/**
* Storing user details in database
* */
public void addUser(int uid,String name, String email) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_ID,uid);
values.put(KEY_NAME, name); // Name
values.put(KEY_EMAIL, email);
// Email
// Inserting Row
long id = db.insert(TABLE_LOGIN, null, values);
Log.d(TAG, "New user inserted into sqlite: " + id);
}
/**
* Getting user data from database
* */
public HashMap<String, String> getUserDetails() {
HashMap<String, String> user = new HashMap<String, String>();
String selectQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// Move to first row
cursor.moveToFirst();
if (cursor.getCount() > 0) {
user.put("name", cursor.getString(1));
user.put("email", cursor.getString(2));
user.put("created_at", cursor.getString(3));
}
cursor.close();
// return user
Log.d(TAG, "Fetching user from Sqlite: " + user.toString());
return user;
}
public HashMap<String, Integer> getUid() {
HashMap<String, Integer> uid = new HashMap<String,Integer>();
String selectQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// Move to first row
cursor.moveToFirst();
Log.d("database", "before uid put");
if (cursor.getCount() > 0) {
uid.put("uid",cursor.getInt(0));
}
cursor.close();
// return user
return uid;
}
/**
* Re crate database Delete all tables and create them again
* */
public void deleteUsers() {
SQLiteDatabase db = this.getWritableDatabase();
// Delete All Rows
db.delete(TABLE_LOGIN, null, null);
Log.d(TAG, "Deleted all user info from sqlite");
}
}