| /* |
| * 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.sql.SQLException; |
| |
| import org.apache.openjpa.jdbc.meta.JavaSQLTypes; |
| import org.apache.openjpa.jdbc.sql.Joins; |
| import org.apache.openjpa.jdbc.sql.Raw; |
| 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.kernel.exps.Value; |
| import org.apache.openjpa.meta.ClassMetaData; |
| |
| /** |
| * General case expression. |
| * |
| * @author Catalina Wei |
| */ |
| public class GeneralCaseExpression |
| extends AbstractVal { |
| |
| |
| private static final long serialVersionUID = 1L; |
| private final Exp[] _exp; |
| private final Val _val; |
| private ClassMetaData _meta = null; |
| private Class _cast = null; |
| private Value other = null; |
| private ExpState otherState = null; |
| |
| /** |
| * Constructor. |
| */ |
| public GeneralCaseExpression(Exp[] exp, Val val) { |
| _exp = exp; |
| _val = val; |
| } |
| |
| public Exp[] getExp() { |
| return _exp; |
| } |
| |
| public Val getVal() { |
| return _val; |
| } |
| |
| @Override |
| public Class getType() { |
| if (_cast != null) |
| return _cast; |
| Class type = _val.getType(); |
| for (Exp exp : _exp) |
| type = Filters.promote(type, |
| ((WhenCondition) exp).getVal().getType()); |
| if (type == Raw.class) |
| return String.class; |
| return type; |
| } |
| |
| @Override |
| public ExpState initialize(Select sel, ExpContext ctx, int flags) { |
| ExpState[] states = new ExpState[_exp.length+1]; |
| Joins joins = null; |
| int i = 0; |
| for (; i < _exp.length; i++) { |
| states[i] = _exp[i].initialize(sel, ctx, null); |
| if (joins == null) |
| joins = states[i].joins; |
| else |
| joins = sel.and(joins, states[i].joins); |
| } |
| states[i] = _val.initialize(sel, ctx, 0); |
| if (joins == null) |
| joins = states[i].joins; |
| else |
| joins = sel.and(joins, states[i].joins); |
| return new GeneralCaseExpState(joins, states); |
| } |
| |
| private static class GeneralCaseExpState |
| extends ExpState { |
| |
| public ExpState[] states; |
| |
| public GeneralCaseExpState(Joins joins, ExpState[] states) { |
| super(joins); |
| this.states = states; |
| } |
| } |
| |
| @Override |
| public void appendTo(Select sel, ExpContext ctx, ExpState state, |
| SQLBuffer buf, int index) { |
| GeneralCaseExpState cstate = (GeneralCaseExpState) state; |
| |
| buf.append(" CASE "); |
| int i = 0; |
| for (; i < _exp.length; i++) |
| _exp[i].appendTo(sel, ctx, cstate.states[i], buf); |
| |
| buf.append(" ELSE "); |
| _val.appendTo(sel, ctx, cstate.states[i], buf, 0); |
| |
| buf.append(" END "); |
| } |
| |
| @Override |
| public void selectColumns(Select sel, ExpContext ctx, ExpState state, |
| boolean pks) { |
| GeneralCaseExpState cstate = (GeneralCaseExpState) state; |
| int i = 0; |
| for (; i < _exp.length; i++) |
| _exp[i].selectColumns(sel, ctx, cstate.states[i], pks); |
| _val.selectColumns(sel, ctx, cstate.states[i], pks); |
| } |
| |
| @Override |
| public void acceptVisit(ExpressionVisitor visitor) { |
| visitor.enter(this); |
| for (Exp exp : _exp) { |
| exp.acceptVisit(visitor); |
| } |
| _val.acceptVisit(visitor); |
| visitor.exit(this); |
| } |
| |
| @Override |
| public int getId() { |
| return Val.SIMPLECASE_VAL; |
| } |
| |
| @Override |
| public void calculateValue(Select sel, ExpContext ctx, ExpState state, |
| Val other, ExpState otherState) { |
| GeneralCaseExpState gstate = (GeneralCaseExpState) state; |
| for (int i = 0; i < _exp.length; i++) { |
| BinaryOpExpState bstate = (BinaryOpExpState) gstate.states[i]; |
| ((WhenCondition) _exp[i]).getVal().calculateValue(sel, ctx, |
| bstate.state2, other, otherState); |
| } |
| _val.calculateValue(sel, ctx, gstate.states[_exp.length], other, |
| otherState); |
| } |
| |
| @Override |
| public void groupBy(Select sel, ExpContext ctx, ExpState state) { |
| sel.groupBy(newSQLBuffer(sel, ctx, state)); |
| } |
| |
| @Override |
| public int length(Select sel, ExpContext ctx, ExpState state) { |
| return 1; |
| } |
| |
| private SQLBuffer newSQLBuffer(Select sel, ExpContext ctx, ExpState state) { |
| calculateValue(sel, ctx, state, (Val)other, otherState); |
| SQLBuffer buf = new SQLBuffer(ctx.store.getDBDictionary()); |
| appendTo(sel, ctx, state, buf, 0); |
| return buf; |
| } |
| |
| @Override |
| public Object load(ExpContext ctx, ExpState state, Result res) |
| throws SQLException { |
| return Filters.convert(res.getObject(this, |
| JavaSQLTypes.JDBC_DEFAULT, null), getType()); |
| } |
| |
| @Override |
| public void orderBy(Select sel, ExpContext ctx, ExpState state, |
| boolean asc) { |
| sel.orderBy(newSQLBuffer(sel, ctx, state), asc, false, getSelectAs()); |
| } |
| |
| @Override |
| public void select(Select sel, ExpContext ctx, ExpState state, boolean pks){ |
| sel.select(newSQLBuffer(sel, ctx, state), this); |
| } |
| |
| @Override |
| public ClassMetaData getMetaData() { |
| return _meta; |
| } |
| |
| @Override |
| public void setImplicitType(Class type) { |
| _cast = type; |
| } |
| |
| @Override |
| public void setMetaData(ClassMetaData meta) { |
| _meta = meta; |
| } |
| public void setOtherPath(Value other) { |
| this.other = other; |
| } |
| |
| public Value getOtherPath() { |
| return other; |
| } |
| |
| public void setOtherState(ExpState otherState) { |
| this.otherState = otherState; |
| } |
| |
| public ExpState getOtherState() { |
| return otherState; |
| } |
| } |
| |