view src/main/java/org/monetdb/jdbc/MonetWrapper.java @ 931:df18aa5c8a61

Add test for MonetDriver.getPropertyInfo(url, props). The implementation is moved to Parameter.java which contains the list of connection parameters. It currently only returns the mandatory connection parameters.
author Martin van Dinther <martin.van.dinther@monetdbsolutions.com>
date Thu, 24 Oct 2024 19:10:06 +0200 (6 months ago)
parents e890195256ac
children d416e9b6b3d0
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/*
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0.  If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2024 MonetDB Foundation;
 * Copyright August 2008 - 2023 MonetDB B.V.;
 * Copyright 1997 - July 2008 CWI.
 */

package org.monetdb.jdbc;

import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;

/**
 *<pre>
 * A Wrapper class which provide the ability to retrieve the delegate instance
 * when the instance in question is in fact a proxy class.
 *
 * The wrapper pattern is employed by many JDBC driver implementations to provide
 * extensions beyond the traditional JDBC API that are specific to a data source.
 * Developers may wish to gain access to these resources that are wrapped (the delegates)
 * as proxy class instances representing the the actual resources.
 * This class contains a standard mechanism to access these wrapped resources
 * represented by their proxy, to permit direct access to the resource delegates.
 *</pre>
 *
 * @author Fabian Groffen, Martin van Dinther
 * @version 1.2
 */
public class MonetWrapper implements java.sql.Wrapper {
	/**
	 * Returns true if this either implements the interface argument or
	 * is directly or indirectly a wrapper for an object that does.
	 * Returns false otherwise. If this implements the interface then
	 * return true, else if this is a wrapper then return the result of
	 * recursively calling <code>isWrapperFor</code> on the wrapped object.
	 * If this does not implement the interface and is not a wrapper, return
	 * false. This method should be implemented as a low-cost operation
	 * compared to <code>unwrap</code> so that callers can use this method to avoid
	 * expensive <code>unwrap</code> calls that may fail.
	 * If this method returns true then calling <code>unwrap</code> with the same argument should succeed.
	 *
	 * @param iface a Class defining an interface.
	 * @return true if this implements the interface or directly or indirectly wraps an object that does.
	 * @throws SQLException if an error occurs while determining whether this is a wrapper
	 * 	for an object with the given interface.
	 * @since 1.6
	 */
	@Override
	public boolean isWrapperFor(final Class<?> iface) throws SQLException {
		return iface != null && iface.isAssignableFrom(getClass());
	}

	/**
	 * Returns an object that implements the given interface to allow
	 * access to non-standard methods, or standard methods not exposed by the proxy.
	 * The result may be either the object found to implement the interface
	 * or a proxy for that object.
	 * If the receiver implements the interface then the result is the receiver
	 * or a proxy for the receiver.
	 * If the receiver is a wrapper and the wrapped object implements the interface
	 * then the result is the wrapped object or a proxy for the wrapped object.
	 * Otherwise return the result of calling <code>unwrap</code> recursively on
	 * the wrapped object or a proxy for that result.
	 * If the receiver is not a wrapper and does not implement the interface,
	 * then an <code>SQLException</code> is thrown.
	 *
	 * @param iface A Class defining an interface that the result must implement.
	 * @return an object that implements the interface. May be a proxy for the actual implementing object.
	 * @throws SQLException If no object found that implements the interface
	 * @since 1.6
	 */
	@Override
	@SuppressWarnings("unchecked")
	public <T> T unwrap(final Class<T> iface) throws SQLException {
		if (isWrapperFor(iface)) {
			return (T) this;
		}
		throw new SQLException("Cannot unwrap to interface: " + (iface != null ? iface.getName() : ""), "0A000");
	}


	/**
	 * Small helper method that formats the "Method ... not implemented" message
	 * and creates a new SQLFeatureNotSupportedException object
	 * whose SQLState is set to "0A000": feature not supported.
	 *
	 * @param name the method name
	 * @return a new created SQLFeatureNotSupportedException object with SQLState 0A000
	 */
	static final SQLFeatureNotSupportedException newSQLFeatureNotSupportedException(final String name) {
		return new SQLFeatureNotSupportedException("Method " + name + " not implemented", "0A000");
	}

	/**
	 * General utility function to add double quotes around an SQL Identifier
	 * such as column or table or schema name in SQL queries.
	 * It also adds escapes for special characters: double quotes and the escape character
	 *
	 * FYI: it is made public as it is also called from util/Exporter.java
	 *
	 * @param in the string to quote
	 * @return the double quoted string
	 */
	public static final String dq(final String in) {
		String ret = in;
		if (ret.contains("\\\\"))
			// all double slashes in input need to be escaped.
			ret = ret.replaceAll("\\\\", "\\\\\\\\");
		if (ret.contains("\""))
			// all double quotes in input need to be escaped.
			ret = ret.replaceAll("\"", "\\\\\"");
		return "\"" + ret + "\"";
	}

	/**
	 * General utility function to add single quotes around string literals as used in SQL queries.
	 * It also adds escapes for special characters: single quotes and the escape character
	 *
	 * FYI: it is made public as it is also called from util/Exporter.java
	 *
	 * @param in the string to quote
	 * @return the single quoted string
	 */
	public static final String sq(final String in) {
		String ret = in;
		if (ret.contains("\\\\"))
			// all double slashes in input need to be escaped.
			ret = ret.replaceAll("\\\\", "\\\\\\\\");
		if (ret.contains("'"))
			// all single quotes in input need to be escaped.
			ret = ret.replaceAll("'", "\\\\'");
		return "'" + ret + "'";
	}
}