Hibernate example source code file (QuerySelect.java)

This example Hibernate source code file (QuerySelect.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

dialect, dont_space_tokens, hashset, iterator, joinfragment, joinfragment, mysql, queryjoinfragment, queryselect, queryselect, string, string, stringbuffer, stringbuffer, util

The Hibernate QuerySelect.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.HashSet;
import java.util.Iterator;
import org.hibernate.dialect.Dialect;

/**
 * A translated HQL query
 * @author Gavin King
 */
public class QuerySelect {
	private Dialect dialect;
	private JoinFragment joins;
	private StringBuffer select = new StringBuffer();
	private StringBuffer where = new StringBuffer();
	private StringBuffer groupBy = new StringBuffer();
	private StringBuffer orderBy = new StringBuffer();
	private StringBuffer having = new StringBuffer();
	private String comment;
	private boolean distinct=false;

	private static final HashSet DONT_SPACE_TOKENS = new HashSet();
	static {
		//dontSpace.add("'");
		DONT_SPACE_TOKENS.add(".");
		DONT_SPACE_TOKENS.add("+");
		DONT_SPACE_TOKENS.add("-");
		DONT_SPACE_TOKENS.add("/");
		DONT_SPACE_TOKENS.add("*");
		DONT_SPACE_TOKENS.add("<");
		DONT_SPACE_TOKENS.add(">");
		DONT_SPACE_TOKENS.add("=");
		DONT_SPACE_TOKENS.add("#");
		DONT_SPACE_TOKENS.add("~");
		DONT_SPACE_TOKENS.add("|");
		DONT_SPACE_TOKENS.add("&");
		DONT_SPACE_TOKENS.add("<=");
		DONT_SPACE_TOKENS.add(">=");
		DONT_SPACE_TOKENS.add("=>");
		DONT_SPACE_TOKENS.add("=<");
		DONT_SPACE_TOKENS.add("!=");
		DONT_SPACE_TOKENS.add("<>");
		DONT_SPACE_TOKENS.add("!#");
		DONT_SPACE_TOKENS.add("!~");
		DONT_SPACE_TOKENS.add("!<");
		DONT_SPACE_TOKENS.add("!>");
		DONT_SPACE_TOKENS.add("("); //for MySQL
		DONT_SPACE_TOKENS.add(")");
	}

	public QuerySelect(Dialect dialect) {
		this.dialect = dialect;
		joins = new QueryJoinFragment(dialect, false);
	}

	public JoinFragment getJoinFragment() {
		return joins;
	}

	public void addSelectFragmentString(String fragment) {
		if ( fragment.length()>0 && fragment.charAt(0)==',' ) fragment = fragment.substring(1);
		fragment = fragment.trim();
		if ( fragment.length()>0 ) {
			if ( select.length()>0 ) select.append(", ");
			select.append(fragment);
		}
	}

	public void addSelectColumn(String columnName, String alias) {
		addSelectFragmentString(columnName + ' ' + alias);
	}

	public void setDistinct(boolean distinct) {
		this.distinct = distinct;
	}

	public void setWhereTokens(Iterator tokens) {
		//if ( conjunctiveWhere.length()>0 ) conjunctiveWhere.append(" and ");
		appendTokens(where, tokens);
	}

	public void prependWhereConditions(String conditions) {
		if (where.length() > 0) {
			where.insert(0, conditions + " and ");
		}
		else {
			where.append(conditions);
		}
	}

	public void setGroupByTokens(Iterator tokens) {
		//if ( groupBy.length()>0 ) groupBy.append(" and ");
		appendTokens(groupBy, tokens);
	}

	public void setOrderByTokens(Iterator tokens) {
		//if ( orderBy.length()>0 ) orderBy.append(" and ");
		appendTokens(orderBy, tokens);
	}

	public void setHavingTokens(Iterator tokens) {
		//if ( having.length()>0 ) having.append(" and ");
		appendTokens(having, tokens);
	}

	public void addOrderBy(String orderByString) {
		if ( orderBy.length() > 0 ) orderBy.append(", ");
		orderBy.append(orderByString);
	}

	public String toQueryString() {
		StringBuffer buf = new StringBuffer(50);
		if (comment!=null) buf.append("/* ").append(comment).append(" */ ");
		buf.append("select ");
		if (distinct) buf.append("distinct ");
		String from = joins.toFromFragmentString();
		if ( from.startsWith(",") ) {
			from = from.substring(1);
		}
		else if ( from.startsWith(" inner join") ){
			from = from.substring(11);
		}

		buf.append( select.toString() )
			.append(" from")
			.append(from);

		String outerJoinsAfterWhere = joins.toWhereFragmentString().trim();
		String whereConditions = where.toString().trim();
		boolean hasOuterJoinsAfterWhere = outerJoinsAfterWhere.length() > 0;
		boolean hasWhereConditions = whereConditions.length() > 0;
		if (hasOuterJoinsAfterWhere || hasWhereConditions) {
			buf.append(" where ");
			if (hasOuterJoinsAfterWhere) {
				buf.append( outerJoinsAfterWhere.substring(4) );
			}
			if (hasWhereConditions) {
				if (hasOuterJoinsAfterWhere) {
					buf.append(" and (");
				}
				buf.append(whereConditions);
				if (hasOuterJoinsAfterWhere) {
					buf.append(")");
				}
			}
		}

		if ( groupBy.length() > 0 ) buf.append(" group by ").append( groupBy.toString() );
		if ( having.length() > 0 ) buf.append(" having ").append( having.toString() );
		if ( orderBy.length() > 0 ) buf.append(" order by ").append( orderBy.toString() );

		return dialect.transformSelectString( buf.toString() );
	}

	private static void appendTokens(StringBuffer buf, Iterator iter) {
		boolean lastSpaceable=true;
		boolean lastQuoted=false;
		while ( iter.hasNext() ) {
			String token = (String) iter.next();
			boolean spaceable = !DONT_SPACE_TOKENS.contains(token);
			boolean quoted = token.startsWith("'");
			if (spaceable && lastSpaceable) {
				if ( !quoted || !lastQuoted ) buf.append(' ');
			}
			lastSpaceable = spaceable;
			buf.append(token);
			lastQuoted = token.endsWith("'");
		}
	}

	public void setComment(String comment) {
		this.comment = comment;
	}

	public QuerySelect copy() {
		QuerySelect copy = new QuerySelect(dialect);
		copy.joins = this.joins.copy();
		copy.select.append( this.select.toString() );
		copy.where.append( this.where.toString() );
		copy.groupBy.append( this.groupBy.toString() );
		copy.orderBy.append( this.orderBy.toString() );
		copy.having.append( this.having.toString() );
		copy.comment = this.comment;
		copy.distinct = this.distinct;
		return copy;
	}

}