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Type 4 JDBC driver for Apache Cassandra built on top of existing great libs like java driver from DataStax. It supports Cassandra 2.x and above with improved SQL compatibility.

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/**
 * Copyright (C) 2015-2017, Zhichun Wu
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.github.cassandra.jdbc;

import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.Wrapper;

/**
 * Base class for JDBC implementations of Connection, Statement and ResultSet.
 *
 * @author Zhichun Wu
 */
public abstract class BaseJdbcObject implements AutoCloseable, Wrapper {
    /**
     * List of chained SQL warnings.
     */
    private SQLWarning _warning;

    /**
     * This indicates whether this object has been closed.
     */
    protected boolean closed;

    /**
     * Quiet mode suggests if the driver should throw SQLException for
     * unsupported operation. By default it is true but can be customized by
     * passing "quiet=false" in connection properties.
     */
    protected final boolean quiet;

    protected BaseJdbcObject(boolean quiet) {
        this.closed = false;
        this.quiet = quiet;
    }

    /**
     * Idempotent close method.
     *
     * @return SQLException if any
     */
    protected abstract SQLException tryClose();

    /**
     * This returns the underlying object actually doing the work.
     *
     * @return underlying object
     */
    protected abstract Object unwrap();

    /**
     * Validate instance state - mainly checking if this has been closed.
     *
     * @throws SQLException when state is invalid(e.g. closed
     *                      connection/statement/resultset)
     */
    protected void validateState() throws SQLException {
        if (closed) {
            throw CassandraErrors.resourceClosedException(this);
        }
    }

    /**
     * Append a warning to the end of chained SQL warnings.
     *
     * @param warning warning to be appended to the warnings list
     */
    public void appendWarning(SQLWarning warning) {
        if (warning != null) {
            if (_warning == null) {
                _warning = warning;
            } else {
                SQLWarning w = _warning;
                SQLWarning prevWarning = w;
                do {
                    if (w == warning) {
                        break;
                    } else {
                        prevWarning = w;
                    }
                } while ((w = w.getNextWarning()) != null);

                if (prevWarning != w) {
                    prevWarning.setNextWarning(warning);
                }
            }
        }
    }

    public void clearWarnings() throws SQLException {
        // validateState();

        _warning = null;
    }

    public void close() throws SQLException {
        clearWarnings();

        closed = true;

        SQLException exception = tryClose();
        if (!quiet && exception != null) {
            throw exception;
        }
    }

    public SQLWarning getWarnings() throws SQLException {
        validateState();

        return _warning;
    }

    public boolean isClosed() throws SQLException {
        return closed;
    }

    public boolean isWrapperFor(Class iface) throws SQLException {
        Object innerObj = unwrap();

        return innerObj != null && innerObj.getClass().isAssignableFrom(iface);
    }

    public  T unwrap(Class iface) throws SQLException {
        return iface.cast(unwrap());
    }
}