Hibernate Native SQL Aliased Criterion

NativeSQLAliasedCriterion.java

package org.xmedeko.hibernate;

import org.hibernate.Criteria;
import org.hibernate.EntityMode;
import org.hibernate.HibernateException;
import org.hibernate.criterion.CriteriaQuery;
import org.hibernate.criterion.Criterion;
import org.hibernate.engine.TypedValue;
import org.hibernate.type.Type;
import org.hibernate.util.ArrayHelper;

/**
 * A SQL fragment. The string {alias} will be replaced by the alias of the root entity. Any other aliases or property
 * names will be searched, if provided in {aliasName} manner.
 * 
 * @author Sergey Pulyaev
 * @author xmedeko
 * 
 * @see http://opensource.atlassian.com/projects/hibernate/browse/HHH-2952
 */
public class NativeSQLAliasedCriterion implements Criterion {
	private static final long serialVersionUID = -4025066009045126609L;

	private final String sql;
	private final TypedValue[] typedValues;

	public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
		return applyAliases(criteria, criteriaQuery);
	}

	private String applyAliases(Criteria criteria, CriteriaQuery criteriaQuery) {
		StringBuilder res = new StringBuilder();
		int i = 0;
		int cnt = this.sql.length();
		while (i < cnt) {
			int l = this.sql.indexOf('{', i);
			if (l == -1) {
				break;
			}

			String before = this.sql.substring(i, l);
			res.append(before);

			int r = this.sql.indexOf('}', l);
			String alias = this.sql.substring(l + 1, r);
			if (alias.length() <= 0 || "alias".equals(alias)) { // root alias
				res.append(criteriaQuery.getSQLAlias(criteria));
			} else {
				String[] columns = criteriaQuery.getColumnsUsingProjection(criteria, alias);
				if (columns.length != 1)
					throw new HibernateException("SQLAliasedCriterion may only be used with single-column properties: "
							+ alias);
				res.append(columns[0]);
			}
			i = r + 1;
		}
		String after = this.sql.substring(i, cnt);
		res.append(after);

		return res.toString();
	}

	public TypedValue[] getTypedValues(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
		return typedValues;
	}

	@Override
	public String toString() {
		return sql;
	}

	/**
	 * Constructor. 
	 * @param sql
	 * @param values
	 * @param types
	 */
	public NativeSQLAliasedCriterion(String sql, Object[] values, Type[] types) {
		this.sql = sql;
		typedValues = new TypedValue[values.length];
		for (int i = 0; i < typedValues.length; i++) {
			typedValues[i] = new TypedValue(types[i], values[i], EntityMode.POJO);
		}
	}

	/**
	 * Constructor.
	 * @param sql
	 * @param value
	 * @param type
	 */
	public NativeSQLAliasedCriterion(String sql, Object value, Type type) {
		this(sql, new Object[] { value }, new Type[] { type });
	}

	/**
	 * Constructor.
	 * @param sql
	 */
	public NativeSQLAliasedCriterion(String sql) {
		this(sql, ArrayHelper.EMPTY_OBJECT_ARRAY, ArrayHelper.EMPTY_TYPE_ARRAY);
	}

}