    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.dbutils;
    019
    020import java.sql.CallableStatement;
    021import java.sql.SQLException;
    022
    023/**
    024 * Represents an OUT parameter for a stored procedure.  When running a stored
    025 * procedure with {@link QueryRunner}, pass an instance of
    026 * {@code OutParameter} to indicate that the parameter at that index is an
    027 * OUT parameter.  The value of the parameter may be obtained from the
    028 * {@code OutParameter} instance via {@link #getValue() }.
    029 * <p>
    030 * INOUT parameters are also supported by setting the {@code value} of
    031 * the {@code OutParameter} instance before invoking the stored procedure.
    032 *
    033 * @param <T> the class of the parameter; should be compatible via cast with the
    034 * class returned by the {@code CallableStatement.getObject(int)} method.
    035 */
    036public class OutParameter<T> {
    037    private final int sqlType;
    038    private final Class<T> javaType;
    039    private T value = null;
    040
    041    /**
    042     * Construct an {@code OutParameter} for the given JDBC SQL type and
    043     * Java type.
    044     * @param sqlType the JDBC SQL type of the parameter as in
    045     * {@code java.sql.Types}.
    046     * @param javaType the Java class of the parameter value, cast compatible
    047     * with the type returned by {@code CallableStatement.getObject(int)}
    048     * for the JDBC type given by {@code sqlType}.
    049     */
    050    public OutParameter(final int sqlType, final Class<T> javaType) {
    051        this.sqlType = sqlType;
    052        this.javaType = javaType;
    053    }
    054
    055    /**
    056     * Construct an {@code OutParameter} for the given JDBC SQL type and
    057     * Java type and with the given value.  The parameter will be treated as an
    058     * INOUT parameter if the value is null.
    059     * @param sqlType the JDBC SQL type of the parameter as in
    060     * {@code java.sql.Types}.
    061     * @param javaType the Java class of the parameter value, cast compatible
    062     * with the type returned by {@code CallableStatement.getObject(int)}
    063     * for the JDBC type given by {@code sqlType}.
    064     * @param value the IN value of the parameter
    065     */
    066    public OutParameter(final int sqlType, final Class<T> javaType, final T value) {
    067        this.sqlType = sqlType;
    068        this.javaType = javaType;
    069        this.value = value;
    070    }
    071
    072    /**
    073     * Get the Java class for this OUT parameter.
    074     * @return the Java class for this OUT parameter.
    075     */
    076    public Class<T> getJavaType() {
    077        return javaType;
    078    }
    079
    080    /**
    081     * Get the JDBC SQL type for this OUT parameter.
    082     * @return the JDBC SQL type for this OUT parameter.
    083     */
    084    public int getSqlType() {
    085        return sqlType;
    086    }
    087
    088    /**
    089     * Get the value of the OUT parameter.  After the stored procedure has
    090     * been executed, the value is the value returned via this parameter.
    091     * @return the value of the OUT parameter.
    092     */
    093    public T getValue() {
    094        return value;
    095    }
    096
    097    /**
    098     * Set up the given statement by registering an OUT parameter at the given
    099     * index using the {@code sqlType} and {@code value} of this
    100     * {@code OutParameter}.  If the value is not null, the parameter is
    101     * treated like an INOUT parameter and the value is set on the statement.
    102     * @param stmt the statement the parameter should register on.
    103     * @param index the (1-based) index of the parameter.
    104     * @throws SQLException if the parameter could not be registered, or if the
    105     * value of the parameter could not be set.
    106     */
    107    void register(final CallableStatement stmt, final int index) throws SQLException {
    108        stmt.registerOutParameter(index, sqlType);
    109        if (value != null) {
    110            stmt.setObject(index, value);
    111        }
    112    }
    113
    114    /**
    115     * Set the value using the return value of the parameter an the given index
    116     * from the given {@code CallableStatement}.
    117     * @param stmt the already executed statement
    118     * @param index the (1-based) index of the parameter
    119     * @throws SQLException when the value could not be retrieved from the
    120     * statement.
    121     */
    122    void setValue(final CallableStatement stmt, final int index) throws SQLException {
    123        value = javaType.cast(stmt.getObject(index));
    124    }
    125
    126    /**
    127     * Set the value of the OUT parameter.  If the value is not null when the
    128     * stored procedure is executed, then the parameter will be treated like an
    129     * INOUT parameter.
    130     * @param value the new value for the parameter.
    131     */
    132    public void setValue(final T value) {
    133        this.value = value;
    134    }
    135
    136    @Override
    137    public String toString() {
    138        return "OutParameter{" + "sqlType=" + sqlType + ", javaType="
    139            + javaType + ", value=" + value + '}';
    140    }
    141}