| /* |
| * 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 java.util.Collection; |
| import java.util.Map; |
| |
| import org.apache.openjpa.jdbc.schema.Column; |
| 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.exps.Constant; |
| import org.apache.openjpa.meta.ClassMetaData; |
| |
| /** |
| * A literal or parameter in the filter. |
| * |
| * @author Abe White |
| */ |
| abstract class Const |
| extends AbstractVal |
| implements Constant { |
| |
| |
| private static final long serialVersionUID = 1L; |
| private ClassMetaData _meta = null; |
| |
| @Override |
| public ClassMetaData getMetaData() { |
| return _meta; |
| } |
| |
| @Override |
| public void setMetaData(ClassMetaData meta) { |
| _meta = meta; |
| } |
| |
| /** |
| * Return the SQL value of this constant. |
| */ |
| public Object getSQLValue(Select sel, ExpContext ctx, ExpState state) { |
| return getValue(ctx, state); |
| } |
| |
| /** |
| * Return true if this constant's SQL value is equivalent to NULL. |
| */ |
| public boolean isSQLValueNull(Select sel, ExpContext ctx, ExpState state) { |
| Object val = getSQLValue(sel, ctx, state); |
| if (val == null) |
| return true; |
| if (!(val instanceof Object[])) |
| return false; |
| |
| // all-null array is considered null |
| Object[] arr = (Object[]) val; |
| for (Object o : arr) |
| if (o != null) |
| return false; |
| return true; |
| } |
| |
| /** |
| * Return the value of this constant. May be more robust than the |
| * parameters-only form. |
| */ |
| public Object getValue(ExpContext ctx, ExpState state) { |
| return getValue(ctx.params); |
| } |
| |
| @Override |
| public ExpState initialize(Select sel, ExpContext ctx, int flags) { |
| return new ConstExpState(); |
| } |
| |
| /** |
| * Constant expression state. |
| */ |
| protected static class ConstExpState |
| extends ExpState { |
| |
| public Column[] cols = null; |
| |
| /** |
| * Return the column for the value at the specified index, or null. |
| */ |
| public Column getColumn(int index) { |
| return (cols != null && cols.length > index) ? cols[index] : null; |
| } |
| } |
| |
| @Override |
| public void calculateValue(Select sel, ExpContext ctx, ExpState state, |
| Val other, ExpState otherState) { |
| if (other instanceof PCPath) |
| ((ConstExpState) state).cols = ((PCPath) other). |
| getColumns(otherState); |
| } |
| |
| @Override |
| public void select(Select sel, ExpContext ctx, ExpState state, |
| boolean pks) { |
| sel.select(newSQLBuffer(sel, ctx, state), this); |
| } |
| |
| 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; |
| } |
| |
| @Override |
| public void selectColumns(Select sel, ExpContext ctx, ExpState state, |
| boolean pks) { |
| } |
| |
| @Override |
| public void groupBy(Select sel, ExpContext ctx, ExpState state) { |
| sel.groupBy(newSQLBuffer(sel, ctx, state)); |
| } |
| |
| @Override |
| public void orderBy(Select sel, ExpContext ctx, ExpState state, |
| boolean asc) { |
| sel.orderBy(newSQLBuffer(sel, ctx, state), asc, false, getSelectAs()); |
| } |
| |
| @Override |
| public Object load(ExpContext ctx, ExpState state, Result res) |
| throws SQLException { |
| return getValue(ctx, state); |
| } |
| |
| @Override |
| public int length(Select sel, ExpContext ctx, ExpState state) { |
| return 1; |
| } |
| |
| @Override |
| public void appendIsEmpty(Select sel, ExpContext ctx, ExpState state, |
| SQLBuffer sql) { |
| Object obj = getValue(ctx, state); |
| if (obj instanceof Collection && ((Collection) obj).isEmpty()) |
| sql.append(TRUE); |
| else if (obj instanceof Map && ((Map) obj).isEmpty()) |
| sql.append(TRUE); |
| else |
| sql.append(FALSE); |
| } |
| |
| @Override |
| public void appendIsNotEmpty(Select sel, ExpContext ctx, ExpState state, |
| SQLBuffer sql){ |
| Object obj = getValue(ctx, state); |
| if (obj instanceof Collection && ((Collection) obj).isEmpty()) |
| sql.append(FALSE); |
| else if (obj instanceof Map && ((Map) obj).isEmpty()) |
| sql.append(FALSE); |
| else |
| sql.append(TRUE); |
| } |
| |
| @Override |
| public void appendSize(Select sel, ExpContext ctx, ExpState state, |
| SQLBuffer sql) { |
| Object obj = getValue(ctx, state); |
| if (obj instanceof Collection) |
| sql.appendValue(((Collection) obj).size()); |
| else if (obj instanceof Map) |
| sql.appendValue(((Map) obj).size()); |
| else |
| sql.append("1"); |
| } |
| |
| @Override |
| public void appendIsNull(Select sel, ExpContext ctx, ExpState state, |
| SQLBuffer sql) { |
| if (isSQLValueNull(sel, ctx, state)) |
| sql.append(TRUE); |
| else |
| sql.append(FALSE); |
| } |
| |
| @Override |
| public void appendIsNotNull(Select sel, ExpContext ctx, ExpState state, |
| SQLBuffer sql) { |
| if (!isSQLValueNull(sel, ctx, state)) |
| sql.append(TRUE); |
| else |
| sql.append(FALSE); |
| } |
| } |