SQLite连接池

我想在android中有一个连接池，因为并行线程必须同时访问数据库。

Android提供了与javax.sql连接一起使用的PooledConnection接口。 由于在Android中没有正式支持jdbc for SQLite，我想到了另一种方法，即实现SQLite数据库的连接池。

你怎么看待这种方法。 有什么风险？ 我忽视了什么吗？

我的代码如下：

数据库的连接包装类：

 public class PoolConnection { protected SQLiteDatabase sqlDb; protected long openedAt; private static final String DB_NAME = Environment .getExternalStorageDirectory() + "/data/DBNAME.sqlite"; private static final int DB_VERSION = 1; private static class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DB_NAME, null, DB_VERSION); } @Override public void onCreate(SQLiteDatabase db) { // nothing to do here } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // no upgrade planned yet } } public PoolConnection(Context context) throws Exception { sqlDb = new DatabaseHelper(context).getWritableDatabase(); openedAt = System.currentTimeMillis(); } public boolean isAvailable() { if (!sqlDb.isOpen() || sqlDb.inTransaction() || sqlDb.isDbLockedByOtherThreads()) { return false; } else { return true; } } public void close() throws SQLException { sqlDb.close(); } public SQLiteDatabase getConnection() throws SQLException { return sqlDb; } public long getOpenedAt() { return openedAt; } } 

和连接池类：

 public class ConnectionPool { protected List connections; protected long maxIdleTime = 30 * 1000; public ConnectionPool() { connections = Collections .synchronizedList(new ArrayList()); new PoolCleaner(maxIdleTime).start(); } public PoolConnection getConnection(Context context) throws Exception { synchronized (connections) { PoolConnection poolCon = null; for (PoolConnection con : connections) { poolCon = con; if (poolCon.isAvailable()) { return poolCon; } } } PoolConnection con = new PoolConnection(context); synchronized (connections) { connections.add(con); } return con; } public void removeExpired() { synchronized (connections) { for (int i = (connections.size() - 1); i >= 0; i--) { PoolConnection con = connections.get(i); if (con.isAvailable() && maxIdleTime < (System.currentTimeMillis() - con .getOpenedAt())) { try { con.close(); } catch (SQLException e) { e.printStackTrace(); } connections.remove(i); } } } } class PoolCleaner extends Thread { protected long cleaningInterval; protected boolean mustStop; public PoolCleaner(long cleaningInterval) { if (cleaningInterval = 0"); } this.mustStop = false; this.cleaningInterval = cleaningInterval; setDaemon(true); } public void run() { while (!mustStop) { try { sleep(cleaningInterval); } catch (InterruptedException ignore) { } if (mustStop) { break; } removeExpired(); } } public void halt() { mustStop = true; synchronized (this) { this.interrupt(); } } } } 

Answer 1

有用的相关主题，接受的答案专门解决multithreading访问：

Android上SQLite的最佳做法是什么？

Answer 2

在我确定没有其他可用的东西之前，我不会编写自己的连接池。 Apache Commons有一个数据库连接池类。 考虑将另一个依赖项与使用自己的维护负担进行权衡。