package com.example.ipcplayer.cache.db;
import java.util.ArrayList;
import java.util.List;
import com.example.ipcplayer.cache.CacheEntity;
import com.example.ipcplayer.utils.LogUtil;
import com.example.ipcplayer.utils.StringUtil;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.provider.BaseColumns;
public class CacheDBHelper extends SQLiteOpenHelper{
private static final String TAG = CacheDBHelper.class.getSimpleName();
private static CacheDBHelper mInstance = null;
private SQLiteDatabase mDB = null;
/** 最多存200条*/
private static int MAX_ROW_COUNT = 200;
public CacheDBHelper(Context context) {
super(context, CacheDBConfig.DB_NAME, null, CacheDBConfig.DB_VERSION);
openDB();
}
public static CacheDBHelper getInstance(Context context){
if(mInstance != null){
return mInstance;
}
synchronized (CacheDBHelper.class) {
if(mInstance == null){
mInstance = new CacheDBHelper(context);
}
}
return mInstance;
}
@Override
public void onCreate(SQLiteDatabase db) {
LogUtil.d(TAG + " oncreate ");
createTable(db);
mDB = db;
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
dropTable(db);
createTable(db);
}
private void openDB(){
try{
mDB = getWritableDatabase();
LogUtil.d(TAG + " openDB");
}catch(Exception e){
e.printStackTrace();
mDB = null;
}
}
private void createTable(SQLiteDatabase db){
try{
String sql = " CREATE TABLE IF NOT EXISTS "
+ CacheDBConfig.Cache.TABLE_NAME + " (" + BaseColumns._ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT,"
+ CacheDBConfig.Cache.KEY + " TEXT UNIQUE,"
+ CacheDBConfig.Cache.DATA + " TEXT NOT NULL,"
+ CacheDBConfig.Cache.ENTER_TIME + " INTEGER NOT NULL,"
+ CacheDBConfig.Cache.LAST_USED_TIME + " INTEGER NOT NULL,"
+ CacheDBConfig.Cache.VALID_TIME + " INTEGER NOT NULL);";
LogUtil.d(TAG + " createtabel sql = " + sql);
db.execSQL(sql);
}catch(Exception e){
LogUtil.d(TAG + " create table error ");
}
}
private void dropTable(SQLiteDatabase db){
try{
db.execSQL(" DROP TABLE IF EXISTS " + CacheDBConfig.Cache.TABLE_NAME);
}catch(Exception e){
LogUtil.d(TAG + " drop table error " );
e.printStackTrace();
}
}
/**
* 设置最多存储数目
* @param count
*/
public void setMaxCount(int count){
MAX_ROW_COUNT = count;
}
/**
* 插入缓存数据
* @param entity
*/
public void insert(CacheEntity entity){
if(entity == null){
return ;
}
LogUtil.d(TAG + " insert into DB , entity = " + entity.toString());
String key = entity.getKey();
String data = entity.getData();
long enterTime = entity.getEnterTime();
long lastUsedTime = entity.getLastUsedTime();
long validTime = entity.getValidTime();
if(StringUtil.isEmpty(key) || StringUtil.isEmpty(data)){
return ;
}
delete(key);
ContentValues values = new ContentValues();
values.put(CacheDBConfig.Cache.KEY, key);
values.put(CacheDBConfig.Cache.DATA, data);
values.put(CacheDBConfig.Cache.ENTER_TIME, enterTime);
values.put(CacheDBConfig.Cache.LAST_USED_TIME, lastUsedTime);
values.put(CacheDBConfig.Cache.VALID_TIME, validTime);
LogUtil.d(TAG + " insert into DB, values = " + values.toString());
try{
mDB.insert(CacheDBConfig.Cache.TABLE_NAME, null, values);
triggerDelete();
}catch(Exception e){
LogUtil.d(TAG + " insert error " );
e.printStackTrace();
}
}
/**
* 获取key缓存对象
* @param key
* @return
*/
public CacheEntity get(String key,CacheEntity entity){
if(StringUtil.isEmpty(key)){
LogUtil.d(TAG + " get error key is null ");
return null;
}
LogUtil.d(TAG + " get, key = " + key);
String selection = CacheDBConfig.Cache.KEY + " = ?";
String[] selectionArgs = new String[1];
selectionArgs[0] = key;
Cursor cursor = null;
try{
cursor = mDB.query(CacheDBConfig.Cache.TABLE_NAME, null, selection, selectionArgs, null, null, null);
if(cursor == null ){
return null;
}
if(cursor.getCount() == 0){
cursor.close();
return null;
}
cursor.moveToFirst();
entity = getCacheEntityFromCursor(cursor,entity);
}catch(Exception e){
e.printStackTrace();
cursor = null;
}finally{
if(cursor != null){
cursor.close();
cursor = null;
}
}
return entity;
}
/**
* 从cursor中读取缓存数据 ，构建成CacheEntity对象
* @param cursor
* @return
*/
private CacheEntity getCacheEntityFromCursor(Cursor cursor,CacheEntity entity){
LogUtil.d(TAG + " getCacheEntityFromCursor");
if(cursor == null || cursor.getCount() == 0 || entity == null){
return null;
}
entity.setKey(cursor.getString(cursor.getColumnIndex(CacheDBConfig.Cache.KEY)));
entity.setData(cursor.getString(cursor.getColumnIndex(CacheDBConfig.Cache.DATA)));
entity.setEnterTime(cursor.getLong(cursor.getColumnIndex(CacheDBConfig.Cache.ENTER_TIME)));
entity.setValidTime(cursor.getLong(cursor.getColumnIndex(CacheDBConfig.Cache.VALID_TIME)));
entity.setLastUsedTime(cursor.getLong(cursor.getColumnIndex(CacheDBConfig.Cache.LAST_USED_TIME)));
LogUtil.d(TAG + " getCacheEntityFromCursor, entity = " + entity.toString());
return entity;
}
/**
* 更新缓存数据的lastUsedTime validTime
* @param entity
*/
public void update(CacheEntity entity){
if(entity == null){
LogUtil.d(TAG + " update error entity is null");
return ;
}
LogUtil.d(TAG + " update DB , entity = " + entity.toString());
ContentValues values = new ContentValues();
values.put(CacheDBConfig.Cache.LAST_USED_TIME, entity.getLastUsedTime());
values.put(CacheDBConfig.Cache.VALID_TIME, entity.getValidTime());
String whereClause = CacheDBConfig.Cache.KEY + " =?";
String[] whereArgs = new String[1];
whereArgs[0] = entity.getKey();
mDB.update(CacheDBConfig.Cache.TABLE_NAME, values, whereClause, whereArgs);
}
/**
* 删除key 缓存数据
* @param key
*/
public void delete(String key){
if(StringUtil.isEmpty(key)){
LogUtil.d(TAG + " delete error key is null ");
return ;
}
LogUtil.d(TAG + " delete key = " + key);
String[] whereArgs = new String[1];
whereArgs[0] = key;
mDB.delete(CacheDBConfig.Cache.TABLE_NAME, CacheDBConfig.Cache.KEY + " = ?", whereArgs);
}
/**
* 删除大于最大存储数的数据
*/
private void triggerDelete(){
String whereClause = " _id IN (SELECT _id FROM "
+ CacheDBConfig.Cache.TABLE_NAME + " ORDER BY "
+ CacheDBConfig.Cache.LAST_USED_TIME
+ " LIMIT 0, max((SELECT COUNT(*) FROM CACHE) - " + MAX_ROW_COUNT
+ ", 0))";
LogUtil.d(TAG + " triggerDelete whereClause= " + whereClause);
mDB.delete(CacheDBConfig.Cache.TABLE_NAME, whereClause, null);
}
/**
* 查询所有的缓存数据
* @return List<CacheEntity>
*/
public List<CacheEntity> queryAll(){
List<CacheEntity> entityList = new ArrayList<CacheEntity>();
Cursor cursor = null;
try{
cursor = mDB.query(CacheDBConfig.Cache.TABLE_NAME, null, null, null, null, null, null);
if(cursor == null){
return null;
}
if(cursor.getCount() == 0){
cursor.close();
return null;
}
while (cursor.moveToNext()) {
CacheEntity entity = new CacheEntity();
entity = getCacheEntityFromCursor(cursor,entity);
entityList.add(entity);
}
}catch(Exception e){
e.printStackTrace();
cursor = null;
}finally{
if(cursor != null){
cursor.close();
cursor = null;
}
}
return entityList;
}
private void closeDB(){
if(mDB != null && mDB.isOpen()){
try{
mDB.close();
}catch(Exception e){
LogUtil.d(TAG + " closeDB error ...");
e.printStackTrace();
}
}
}
@Override
protected void finalize() throws Throwable {
super.finalize();
closeDB();
}
}