sharding-jdbc中AbstractDataSourceAdapter的用法
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本文主要研究一下sharding-jdbc的AbstractDataSourceAdapter
AbstractUnsupportedOperationDataSource
incubator-shardingsphere-4.0.0-RC1/sharding-jdbc/sharding-jdbc-core/src/main/java/org/apache/shardingsphere/shardingjdbc/jdbc/unsupported/AbstractUnsupportedOperationDataSource.java
public abstract class AbstractUnsupportedOperationDataSource extends WrapperAdapter implements DataSource { @Override public final int getLoginTimeout() throws SQLException { throw new SQLFeatureNotSupportedException("unsupported getLoginTimeout()"); } @Override public final void setLoginTimeout(final int seconds) throws SQLException { throw new SQLFeatureNotSupportedException("unsupported setLoginTimeout(int seconds)"); } }
AbstractUnsupportedOperationDataSource继承了WrapperAdapter,声明实现javax.sql.DataSource接口,其覆盖了getLoginTimeout、setLoginTimeout方法,抛出SQLFeatureNotSupportedException异常
AbstractDataSourceAdapter
incubator-shardingsphere-4.0.0-RC1/sharding-jdbc/sharding-jdbc-core/src/main/java/org/apache/shardingsphere/shardingjdbc/jdbc/adapter/AbstractDataSourceAdapter.java
@Getter @Setter public abstract class AbstractDataSourceAdapter extends AbstractUnsupportedOperationDataSource implements AutoCloseable { private final DatabaseType databaseType; private final MapdataSourceMap; private ShardingTransactionManagerEngine shardingTransactionManagerEngine = new ShardingTransactionManagerEngine(); private PrintWriter logWriter = new PrintWriter(System.out); public AbstractDataSourceAdapter(final Map dataSourceMap) throws SQLException { databaseType = getDatabaseType(dataSourceMap.values()); shardingTransactionManagerEngine.init(databaseType, dataSourceMap); this.dataSourceMap = dataSourceMap; } protected final DatabaseType getDatabaseType(final Collection dataSources) throws SQLException { DatabaseType result = null; for (DataSource each : dataSources) { DatabaseType databaseType = getDatabaseType(each); Preconditions.checkState(null == result || result.equals(databaseType), String.format("Database type inconsistent with '%s' and '%s'", result, databaseType)); result = databaseType; } return result; } private DatabaseType getDatabaseType(final DataSource dataSource) throws SQLException { if (dataSource instanceof AbstractDataSourceAdapter) { return ((AbstractDataSourceAdapter) dataSource).databaseType; } try (Connection connection = dataSource.getConnection()) { return DatabaseType.valueFrom(connection.getMetaData().getDatabaseProductName()); } } @Override public final Logger getParentLogger() { return Logger.getLogger(Logger.GLOBAL_LOGGER_NAME); } @Override public final Connection getConnection(final String username, final String password) throws SQLException { return getConnection(); } @Override public void close() throws Exception { for (DataSource each : dataSourceMap.values()) { try { Method method = each.getClass().getDeclaredMethod("close"); method.setAccessible(true); method.invoke(each); } catch (final ReflectiveOperationException ignored) { } } shardingTransactionManagerEngine.close(); } }
AbstractDataSourceAdapter继承了AbstractUnsupportedOperationDataSource,实现了AutoCloseable接口;它的构造器接收一个DataSource的map,并执行shardingTransactionManagerEngine.init;close方法会遍历dataSourceMap,挨个反射调用执行close方法
ShardingTransactionManagerEngine
incubator-shardingsphere-4.0.0-RC1/sharding-transaction/sharding-transaction-core/src/main/java/org/apache/shardingsphere/transaction/ShardingTransactionManagerEngine.java
@Slf4j public final class ShardingTransactionManagerEngine { private final MaptransactionManagerMap = new HashMap<>(); public ShardingTransactionManagerEngine() { loadShardingTransactionManager(); } private void loadShardingTransactionManager() { for (ShardingTransactionManager each : ServiceLoader.load(ShardingTransactionManager.class)) { if (transactionManagerMap.containsKey(each.getTransactionType())) { log.warn("Find more than one {} transaction manager implementation class, use `{}` now", each.getTransactionType(), transactionManagerMap.get(each.getTransactionType()).getClass().getName()); continue; } transactionManagerMap.put(each.getTransactionType(), each); } } /** * Initialize sharding transaction managers. * * @param databaseType database type * @param dataSourceMap data source map */ public void init(final DatabaseType databaseType, final Map dataSourceMap) { for (Entry entry : transactionManagerMap.entrySet()) { entry.getValue().init(databaseType, getResourceDataSources(dataSourceMap)); } } private Collection getResourceDataSources(final Map dataSourceMap) { List result = new LinkedList<>(); for (Map.Entry entry : dataSourceMap.entrySet()) { result.add(new ResourceDataSource(entry.getKey(), entry.getValue())); } return result; } /** * Get sharding transaction manager. * * @param transactionType transaction type * @return sharding transaction manager */ public ShardingTransactionManager getTransactionManager(final TransactionType transactionType) { ShardingTransactionManager result = transactionManagerMap.get(transactionType); if (TransactionType.LOCAL != transactionType) { Preconditions.checkNotNull(result, "Cannot find transaction manager of [%s]", transactionType); } return result; } /** * Close sharding transaction managers. * * @throws Exception exception */ public void close() throws Exception { for (Entry entry : transactionManagerMap.entrySet()) { entry.getValue().close(); } } }
ShardingTransactionManagerEngine维护了ShardingTransactionManager的map,其构造器执行loadShardingTransactionManager方法,它会使用ServiceLoader.load(ShardingTransactionManager.class)加载,然后放入transactionManagerMap中;init方法会遍历transactionManagerMap,然后挨个执行init方法;close方法则遍历transactionManagerMap,挨个执行close方法
小结
AbstractDataSourceAdapter继承了AbstractUnsupportedOperationDataSource,实现了AutoCloseable接口;它的构造器接收一个DataSource的map,并执行shardingTransactionManagerEngine.init;close方法会遍历dataSourceMap,挨个反射调用执行close方法
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