/*
* Copyright 2004-2011 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.engine;
import org.h2.api.AggregateFunction;
import org.h2.command.Parser;
import org.h2.message.DbException;
import org.h2.message.Trace;
import org.h2.table.Table;
import org.h2.util.Utils;
/**
* Represents a user-defined aggregate function.
*/
public class UserAggregate extends DbObjectBase {
private String className;
private Class<?> javaClass;
public UserAggregate(Database db, int id, String name, String className, boolean force) {
initDbObjectBase(db, id, name, Trace.FUNCTION);
this.className = className;
if (!force) {
getInstance();
}
}
public AggregateFunction getInstance() {
if (javaClass == null) {
javaClass = Utils.loadUserClass(className);
}
Object obj;
try {
obj = javaClass.newInstance();
AggregateFunction agg = (AggregateFunction) obj;
return agg;
} catch (Exception e) {
throw DbException.convert(e);
}
}
public String getCreateSQLForCopy(Table table, String quotedName) {
throw DbException.throwInternalError();
}
public String getDropSQL() {
return "DROP AGGREGATE IF EXISTS " + getSQL();
}
public String getCreateSQL() {
return "CREATE FORCE AGGREGATE " + getSQL() + " FOR " + Parser.quoteIdentifier(className);
}
public int getType() {
return DbObject.AGGREGATE;
}
public synchronized void removeChildrenAndResources(Session session) {
database.removeMeta(session, getId());
className = null;
javaClass = null;
invalidate();
}
public void checkRename() {
throw DbException.getUnsupportedException("AGGREGATE");
}
public String getJavaClassName() {
return this.className;
}
}