org.tentackle.dbms.StatementKey Maven / Gradle / Ivy
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/*
* Tentackle - http://www.tentackle.org.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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 library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.tentackle.dbms;
import java.util.Objects;
import org.tentackle.reflect.ReflectionHelper;
/**
* The statement key.
*
* The key describes the statement within its usage scope, i.e. the StatementId and using class.
* The using class is necessary to locate the prepared statement because a select method may be
* implemented in a superclass of the actual class using the statement, which may result in a
* different SQL string.
*
* As an alternative, a statement key may be expressed directly by an SQL string.
* In this case, no using class is required. Notice that ths SQL string must be
* exactly the string sent to the database backend! If there are different backends
* with different SQLs, each SQL must get its own statement key.
*
* @author harald
*/
public class StatementKey {
/**
* The global statement id.
*/
private final StatementId statementId;
/**
* The persistent object class.
*/
private final Class usingClass;
/**
* The SQL string.
*/
private final String sql;
/**
* Creates the statement key.
*
* @param statementId the global statement id
* @param usingClass the using class
*/
public StatementKey(StatementId statementId, Class usingClass) {
if (statementId == null) {
throw new IllegalArgumentException("statementId must not be null");
}
if (usingClass == null) {
throw new IllegalArgumentException("usingClass must not be null");
}
this.statementId = statementId;
this.usingClass = usingClass;
this.sql = null;
}
/**
* Creates a statement key.
*
* @param sql the SQL string
*/
public StatementKey(String sql) {
this.statementId = null;
this.usingClass = null;
if (sql == null || sql.isEmpty()) {
throw new IllegalArgumentException("sql must not be null or empty");
}
this.sql = sql;
}
/**
* Gets the statement id.
*
* @return the id, null if SQL key
*/
public StatementId getStatementId() {
return statementId;
}
/**
* Gets the using class.
*
* @return the class, null if SQL key
*/
public Class getUsingClass() {
return usingClass;
}
/**
* Gets the SQL string.
*
* @return the SQL, null if statement id key
*/
public String getSql() {
return sql;
}
@Override
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append('<');
if (sql != null) {
buf.append(sql);
}
else {
buf.append(ReflectionHelper.getClassBaseName(usingClass)).append('#').append(statementId);
}
buf.append('>');
return buf.toString();
}
@Override
public int hashCode() {
int hash = 7;
hash = 29 * hash + Objects.hashCode(this.statementId);
hash = 29 * hash + Objects.hashCode(this.usingClass);
hash = 29 * hash + Objects.hashCode(this.sql);
return hash;
}
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final StatementKey other = (StatementKey) obj;
if (!Objects.equals(this.statementId, other.statementId)) {
return false;
}
if (!Objects.equals(this.usingClass, other.usingClass)) {
return false;
}
return Objects.equals(this.sql, other.sql);
}
}