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/*
* Copyright (c) 2012-2023, jcabi.com
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met: 1) Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer. 2) Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution. 3) Neither the name of the jcabi.com nor
* the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.jcabi.jdbc;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Date;
import java.util.UUID;
import lombok.EqualsAndHashCode;
import lombok.RequiredArgsConstructor;
import lombok.ToString;
/**
* Outcome that returns first column in the first row.
*
* Use it when you need the first column in the first row:
*
*
Long id = new JdbcSession(source)
* .sql("SELECT id FROM user WHERE name = ?")
* .set("Jeff Lebowski")
* .select(new SingleOutcome<Long>(Long.class));
*
* Supported types are: {@link String}, {@link Long}, {@link Boolean},
* {@link Byte}, {@link Date}, {@link UUID}, and {@link Utc}.
*
*
By default, the outcome throws {@link SQLException} if no records
* are found in the {@link ResultSet}. You can change this behavior by using
* a two-arguments constructor ({@code null} will be returned if
* {@link ResultSet} is empty):
*
*
String name = new JdbcSession(source)
* .sql("SELECT name FROM user WHERE id = ?")
* .set(555)
* .select(new SingleOutcome<Long>(Long.class), true);
* if (name == null) {
* // such a record wasn't found in the database
* }
*
* @param Type of items
* @since 0.1.8
*/
@ToString
@EqualsAndHashCode(of = {"mapping", "silently"})
@RequiredArgsConstructor
public final class SingleOutcome implements Outcome {
/**
* The type.
*/
private final Mapping extends T> mapping;
/**
* Silently return NULL if no row found.
*/
private final boolean silently;
/**
* Public ctor.
*
* @param tpe The type to convert to
*/
public SingleOutcome(final Class tpe) {
this(tpe, false);
}
/**
* Public ctor.
*
* @param tpe The type to convert to
* @param slnt Silently return NULL if there is no row
*/
@SuppressWarnings("PMD.ConstructorOnlyInitializesOrCallOtherConstructors")
public SingleOutcome(final Class tpe, final boolean slnt) {
this(
tpe,
Outcome.DEFAULT_MAPPINGS,
slnt
);
}
/**
* Public ctor.
*
* @param tpe The type to convert to
* @param mps The mappings
* @param slnt Silently return NULL if there is no row
*/
public SingleOutcome(final Class tpe, final Mappings mps, final boolean slnt) {
this(mps.forType(tpe), slnt);
}
@Override
public T handle(final ResultSet rset, final Statement stmt)
throws SQLException {
T result = null;
if (rset.next()) {
result = this.fetch(rset);
} else if (!this.silently) {
throw new SQLException("No records found");
}
return result;
}
/**
* Fetch the value from result set.
*
* @param rset Result set
* @return The result
* @throws SQLException If some error inside
*/
private T fetch(final ResultSet rset) throws SQLException {
return this.mapping.map(rset);
}
}
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