/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.openjpa.jdbc.kernel.exps;
import java.lang.Math;
import java.sql.SQLException;
import org.apache.openjpa.jdbc.meta.JavaSQLTypes;
import org.apache.openjpa.jdbc.sql.DBDictionary;
import org.apache.openjpa.jdbc.sql.Joins;
import org.apache.openjpa.jdbc.sql.Result;
import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.Select;
import org.apache.openjpa.kernel.Filters;
import org.apache.openjpa.kernel.exps.ExpressionVisitor;
import org.apache.openjpa.meta.ClassMetaData;
/**
* Returns the number of characters in a string.
*
* @author Marc Prud'hommeaux
*/
public class Trim
extends AbstractVal {
private final Val _val;
private final Val _trimChar;
private final Boolean _where;
private ClassMetaData _meta = null;
/**
* Constructor. Provide the string to operate on.
*/
public Trim(Val val, Val trimChar, Boolean where) {
_val = val;
_trimChar = trimChar;
_where = where;
}
public Val getVal() {
return _val;
}
public Val getTrimChar() {
return _trimChar;
}
public Boolean getWhere(){
return _where;
}
public ClassMetaData getMetaData() {
return _meta;
}
public void setMetaData(ClassMetaData meta) {
_meta = meta;
}
public Class getType() {
return String.class;
}
public void setImplicitType(Class type) {
}
public ExpState initialize(Select sel, ExpContext ctx, int flags) {
ExpState valueState = _val.initialize(sel, ctx, 0);
ExpState charState = _trimChar.initialize(sel, ctx, 0);
return new TrimExpState(sel.and(valueState.joins, charState.joins),
valueState, charState);
}
/**
* Expression state.
*/
private static class TrimExpState
extends ExpState {
public final ExpState valueState;
public final ExpState charState;
public TrimExpState(Joins joins, ExpState valueState,
ExpState charState) {
super(joins);
this.valueState = valueState;
this.charState = charState;
}
}
public void select(Select sel, ExpContext ctx, ExpState state,
boolean pks) {
sel.select(newSQLBuffer(sel, ctx, state), this);
}
public void selectColumns(Select sel, ExpContext ctx, ExpState state,
boolean pks) {
TrimExpState tstate = (TrimExpState) state;
_val.selectColumns(sel, ctx, tstate.valueState, true);
_trimChar.selectColumns(sel, ctx, tstate.charState, true);
}
public void groupBy(Select sel, ExpContext ctx, ExpState state) {
sel.groupBy(newSQLBuffer(sel, ctx, state));
}
public void orderBy(Select sel, ExpContext ctx, ExpState state,
boolean asc) {
sel.orderBy(newSQLBuffer(sel, ctx, state), asc, false, getSelectAs());
}
private SQLBuffer newSQLBuffer(Select sel, ExpContext ctx, ExpState state) {
calculateValue(sel, ctx, state, null, null);
SQLBuffer buf = new SQLBuffer(ctx.store.getDBDictionary());
appendTo(sel, ctx, state, buf, 0);
return buf;
}
public Object load(ExpContext ctx, ExpState state, Result res)
throws SQLException {
return Filters.convert(res.getObject(this,
JavaSQLTypes.JDBC_DEFAULT, null), getType());
}
public void calculateValue(Select sel, ExpContext ctx, ExpState state,
Val other, ExpState otherState) {
TrimExpState tstate = (TrimExpState) state;
_val.calculateValue(sel, ctx, tstate.valueState, null, null);
_trimChar.calculateValue(sel, ctx, tstate.charState, null, null);
}
public int length(Select sel, ExpContext ctx, ExpState state) {
return 1;
}
public void appendTo(Select sel, ExpContext ctx, ExpState state,
SQLBuffer sql, int index) {
DBDictionary dict = ctx.store.getDBDictionary();
String func;
if (_where == null) {
func = dict.trimBothFunction;
dict.assertSupport(func != null, "TrimBothFunction");
} else if (_where.booleanValue()) {
func = dict.trimLeadingFunction;
dict.assertSupport(func != null, "TrimLeadingFunction");
} else {
func = dict.trimTrailingFunction;
dict.assertSupport(func != null, "TrimTrailingFunction");
}
func = dict.getCastFunction(_val, func);
int fromPart = func.indexOf("{0}");
int charPart = func.indexOf("{1}");
if (charPart == -1)
charPart = func.length();
String part1 = func.substring(0, Math.min(fromPart, charPart));
String part2 = func.substring(Math.min(fromPart, charPart) + 3,
Math.max(fromPart, charPart));
String part3 = null;
if (charPart != func.length())
part3 = func.substring(Math.max(fromPart, charPart) + 3);
TrimExpState tstate = (TrimExpState) state;
sql.append(part1);
if (fromPart < charPart)
_val.appendTo(sel, ctx, tstate.valueState, sql, 0);
else
_trimChar.appendTo(sel, ctx, tstate.charState, sql, 0);
sql.append(part2);
if (charPart != func.length()) {
if (fromPart > charPart)
_val.appendTo(sel, ctx, tstate.valueState, sql, 0);
else
_trimChar.appendTo(sel, ctx, tstate.charState, sql, 0);
sql.append(part3);
} else {
// since the trim statement did not specify the token for
// where to specify the trim char (denoted by "{1}"),
// we do not have the ability to trim off non-whitespace
// characters; throw an exception when we attempt to do so
if (!(_trimChar instanceof Const) || String.valueOf(((Const)
_trimChar).getValue(ctx,tstate.charState)).trim().length() != 0)
dict.assertSupport(false, "TrimNonWhitespaceCharacters");
}
}
public void acceptVisit(ExpressionVisitor visitor) {
visitor.enter(this);
_val.acceptVisit(visitor);
_trimChar.acceptVisit(visitor);
visitor.exit(this);
}
public int getId() {
return Val.TRIM_VAL;
}
}