Hibernate example source code file (Select.java)

This example Hibernate source code file (Select.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, lockmode, lockoptions, lockoptions, select, select, string, string, stringbuffer, stringbuffer

The Hibernate Select.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 org.hibernate.LockMode;
import org.hibernate.LockOptions;
import org.hibernate.dialect.Dialect;
import org.hibernate.internal.util.StringHelper;


/**
 * A simple SQL <tt>SELECT statement
 * @author Gavin King
 */
public class Select {

	private String selectClause;
	private String fromClause;
	private String outerJoinsAfterFrom;
	private String whereClause;
	private String outerJoinsAfterWhere;
	private String orderByClause;
	private String groupByClause;
	private String comment;
	private LockOptions lockOptions = new LockOptions();
	public final Dialect dialect;

	private int guesstimatedBufferSize = 20;
	
	public Select(Dialect dialect) {
		this.dialect = dialect;
	}

	/**
	 * Construct an SQL <tt>SELECT statement from the given clauses
	 */
	public String toStatementString() {
		StringBuffer buf = new StringBuffer(guesstimatedBufferSize);
		if ( StringHelper.isNotEmpty(comment) ) {
			buf.append("/* ").append(comment).append(" */ ");
		}
		
		buf.append("select ").append(selectClause)
				.append(" from ").append(fromClause);
		
		if ( StringHelper.isNotEmpty(outerJoinsAfterFrom) ) {
			buf.append(outerJoinsAfterFrom);
		}
		
		if ( StringHelper.isNotEmpty(whereClause) || StringHelper.isNotEmpty(outerJoinsAfterWhere) ) {
			buf.append(" where " );
			// the outerJoinsAfterWhere needs to come before where clause to properly
			// handle dynamic filters
			if ( StringHelper.isNotEmpty(outerJoinsAfterWhere) ) {
				buf.append(outerJoinsAfterWhere);
				if ( StringHelper.isNotEmpty(whereClause) ) {
					buf.append( " and " );
				}
			}
			if ( StringHelper.isNotEmpty( whereClause ) ) {
				buf.append(whereClause);
			}
		}
		
		if ( StringHelper.isNotEmpty(groupByClause) ) {
			buf.append(" group by ").append(groupByClause);
		}
		
		if ( StringHelper.isNotEmpty(orderByClause) ) {
			buf.append(" order by ").append(orderByClause);
		}
		
		if (lockOptions.getLockMode()!=LockMode.NONE) {
			buf.append( dialect.getForUpdateString(lockOptions) );
		}
		
		return dialect.transformSelectString( buf.toString() );
	}

	/**
	 * Sets the fromClause.
	 * @param fromClause The fromClause to set
	 */
	public Select setFromClause(String fromClause) {
		this.fromClause = fromClause;
		this.guesstimatedBufferSize += fromClause.length();
		return this;
	}

	public Select setFromClause(String tableName, String alias) {
		this.fromClause = tableName + ' ' + alias;
		this.guesstimatedBufferSize += fromClause.length();
		return this;
	}

	public Select setOrderByClause(String orderByClause) {
		this.orderByClause = orderByClause;
		this.guesstimatedBufferSize += orderByClause.length();
		return this;
	}

	public Select setGroupByClause(String groupByClause) {
		this.groupByClause = groupByClause;
		this.guesstimatedBufferSize += groupByClause.length();
		return this;
	}

	public Select setOuterJoins(String outerJoinsAfterFrom, String outerJoinsAfterWhere) {
		this.outerJoinsAfterFrom = outerJoinsAfterFrom;

		// strip off any leading 'and' token
		String tmpOuterJoinsAfterWhere = outerJoinsAfterWhere.trim();
		if ( tmpOuterJoinsAfterWhere.startsWith("and") ) {
			tmpOuterJoinsAfterWhere = tmpOuterJoinsAfterWhere.substring(4);
		}
		this.outerJoinsAfterWhere = tmpOuterJoinsAfterWhere;

		this.guesstimatedBufferSize += outerJoinsAfterFrom.length() + outerJoinsAfterWhere.length();
		return this;
	}


	/**
	 * Sets the selectClause.
	 * @param selectClause The selectClause to set
	 */
	public Select setSelectClause(String selectClause) {
		this.selectClause = selectClause;
		this.guesstimatedBufferSize += selectClause.length();
		return this;
	}

	/**
	 * Sets the whereClause.
	 * @param whereClause The whereClause to set
	 */
	public Select setWhereClause(String whereClause) {
		this.whereClause = whereClause;
		this.guesstimatedBufferSize += whereClause.length();
		return this;
	}

	public Select setComment(String comment) {
		this.comment = comment;
		this.guesstimatedBufferSize += comment.length();
		return this;
	}

	/**
	 * Get the current lock mode
	 * @return LockMode
	 * @deprecated Instead use getLockOptions
	 */
	public LockMode getLockMode() {
		return lockOptions.getLockMode();
	}

	/**
	 * Set the lock mode
	 * @param lockMode
	 * @return this object
	 * @deprecated Instead use setLockOptions
	 */
	public Select setLockMode(LockMode lockMode) {
		lockOptions.setLockMode(lockMode);
		return this;
	}

	/**
	 * Get the current lock options
	 * @return LockOptions
	 */
	public LockOptions getLockOptions() {
		return lockOptions;
	}

	/**
	 * Set the lock options
	 * @param lockOptions
	 * @return this object
	 */
	public Select setLockOptions(LockOptions lockOptions) {
		LockOptions.copy(lockOptions, this.lockOptions);
		return this;
	}

}