AbstractColumnValuePredicate.java

/*
 * Copyright (C) 2000 - 2024 Silverpeas
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
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 * This program is distributed in the hope that it will be useful,
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package org.silverpeas.components.mydb.model.predicates;

import org.silverpeas.components.mydb.model.DbColumn;
import org.silverpeas.core.persistence.jdbc.sql.JdbcSqlQuery;

/**
 * Abstract implementation of the {@link ColumnValuePredicate} interface.
 * @author mmoquillon
 */
public abstract class AbstractColumnValuePredicate implements ColumnValuePredicate {

  public static final String NULL_VALUE = "null";
  public static final String EMPTY_VALUE = "@empty@";
  private DbColumn column;
  private Object normalizedValue;

  /**
   * Constructs a new predicate on the specified database table's column and with the given
   * reference value.
   * @param column the column.
   * @param refValue a reference value.
   */
  public AbstractColumnValuePredicate(final DbColumn column, final String refValue) {
    this.column = column;
    this.normalizedValue = normalizeValue(column, refValue);
  }

  /**
   * Constructs an empty predicate. Dedicated to the concrete implementation of a predicate only
   * if they have to perform some specified tasks at initialization time.
   */
  AbstractColumnValuePredicate() {
    // dedicated to the implementors
  }

  private static Object normalizeValue(final DbColumn column, final String value) {
    final Object normalizedValue;
    if (NULL_VALUE.equals(value)) {
      normalizedValue = null;
    } else if (EMPTY_VALUE.equals(value)) {
      normalizedValue = "";
    } else {
      normalizedValue = column.getJdbcValueOf(value);
    }
    return normalizedValue;
  }

  Object getNormalizedValue() {
    return this.normalizedValue;
  }

  @Override
  public DbColumn getColumn() {
    return this.column;
  }

  public abstract JdbcSqlQuery apply(final JdbcSqlQuery query);
}