fix bug: ddl not release connection

package io.shardingjdbc.core.jdbc.core.connection;

import com.google.common.base.Preconditions;

import io.shardingjdbc.core.constant.SQLType;

import io.shardingjdbc.core.hint.HintManagerHolder;

import io.shardingjdbc.core.jdbc.adapter.AbstractConnectionAdapter;

import io.shardingjdbc.core.jdbc.core.datasource.NamedDataSource;

import io.shardingjdbc.core.jdbc.core.statement.ShardingPreparedStatement;

import io.shardingjdbc.core.jdbc.core.statement.ShardingStatement;

import com.google.common.base.Preconditions;

import lombok.Getter;

import lombok.RequiredArgsConstructor;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.Collection;

import java.util.Collections;

import java.util.HashMap;

import java.util.LinkedList;

import java.util.Map;

import java.util.Map.Entry;

/**

 * Connection that support sharding.

    public Collection<Connection> getAllConnections(final String dataSourceName) throws SQLException {

        DataSource dataSource = shardingContext.getShardingRule().getDataSourceMap().get(dataSourceName);

        Preconditions.checkState(null != dataSource, "Missing the rule of %s in DataSourceRule", dataSourceName);

        Collection<DataSource> dataSources = dataSource instanceof MasterSlaveDataSource

                ? ((MasterSlaveDataSource) dataSource).getAllDataSources().values() : Collections.singletonList(dataSource);

        Map<String, DataSource> dataSources;

        if (dataSource instanceof MasterSlaveDataSource) {

            dataSources = ((MasterSlaveDataSource) dataSource).getAllDataSources();

        } else {

            dataSources = new HashMap<>(1, 1);

            dataSources.put(dataSourceName, dataSource);

        }

        Collection<Connection> result = new LinkedList<>();

        for (DataSource each : dataSources) {

            Connection connection = each.getConnection();

        for (Entry<String, DataSource> entry : dataSources.entrySet()) {

            Connection connection = entry.getValue().getConnection();

            replayMethodsInvocation(connection);

            getCachedConnections().put(entry.getKey(), connection);

            result.add(connection);

        }

        return result;