Hibernate example source code file (InFragment.java)

This example Hibernate source code file (InFragment.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

arraylist, illegalargumentexception, infragment, infragment, list, not_null, not_null, null, object, object, string, string, stringbuilder, util

The Hibernate InFragment.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Middleware LLC.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 *
 */
package org.hibernate.sql;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.hibernate.internal.util.StringHelper;

/**
 * An SQL IN expression.
 * <br>
 * <code>... in(...)
 * <br>
 * @author Gavin King
 */
public class InFragment {

	public static final String NULL = "null";
	public static final String NOT_NULL = "not null";

	private String columnName;
	private List values = new ArrayList();

	/**
	 * @param value, an SQL literal, NULL, or NOT_NULL
	 */
	public InFragment addValue(Object value) {
		values.add(value);
		return this;
	}

	public InFragment setColumn(String columnName) {
		this.columnName = columnName;
		return this;
	}

	public InFragment setColumn(String alias, String columnName) {
		this.columnName = StringHelper.qualify( alias, columnName );
		return setColumn(this.columnName);
	}

	public InFragment setFormula(String alias, String formulaTemplate) {
		this.columnName = StringHelper.replace(formulaTemplate, Template.TEMPLATE, alias);
		return setColumn(this.columnName);
	}

	public String toFragmentString() {

                if (values.size() == 0) {
                   return "1=2";
                }

                StringBuilder buf = new StringBuilder(values.size() * 5);

                if (values.size() == 1) {
                   Object value = values.get(0);
                   buf.append(columnName);

                   if (NULL.equals(value)) {
                      buf.append(" is null");
                   } else {
                      if (NOT_NULL.equals(value)) {
                         buf.append(" is not null");
                      } else {
                         buf.append('=').append(value);
                      }
                   }
                   return buf.toString();
                }
                   
                boolean allowNull = false;

                for (Object value : values) {
                   if (NULL.equals(value)) {
                      allowNull = true;
                   } else {
                      if (NOT_NULL.equals(value)) {
                         throw new IllegalArgumentException("not null makes no sense for in expression");
                      }
                   }
                }

                if (allowNull) {
                   buf.append('(').append(columnName).append(" is null or ").append(columnName).append(" in (");
                } else {
                   buf.append(columnName).append(" in (");
                }

                for (Object value : values) {
                   if (NULL.equals(value)) {
                      ;
                   } else {
                      buf.append(value);
                      buf.append(", ");
                   }
                }

                buf.setLength(buf.length() - 2);

                if (allowNull) {
                   buf.append("))");
                } else {
                   buf.append(')');
                }

                return buf.toString();

	}
}