View Javadoc

1   /*
2    * Copyright (c) 2010.  The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  
21  package org.apache.expreval.expr.calculation;
22  
23  import org.apache.expreval.client.NullColumnValueException;
24  import org.apache.expreval.client.ResultMissingColumnException;
25  import org.apache.expreval.expr.Operator;
26  import org.apache.expreval.expr.TypeSupport;
27  import org.apache.expreval.expr.node.DateValue;
28  import org.apache.expreval.expr.node.GenericValue;
29  import org.apache.expreval.expr.node.NumberValue;
30  import org.apache.expreval.expr.node.StringValue;
31  import org.apache.hadoop.hbase.hbql.client.HBqlException;
32  import org.apache.hadoop.hbase.hbql.impl.HConnectionImpl;
33  
34  public class DelegateCalculation extends GenericCalculation {
35  
36      public DelegateCalculation(final GenericValue arg0, final Operator operator, final GenericValue arg1) {
37          super(null, arg0, operator, arg1);
38      }
39  
40      public Class<? extends GenericValue> validateTypes(final GenericValue parentExpr,
41                                                         final boolean allowCollections) throws HBqlException {
42  
43          final Class<? extends GenericValue> type1 = this.getExprArg(0).validateTypes(this, false);
44          final Class<? extends GenericValue> type2 = this.getExprArg(1).validateTypes(this, false);
45  
46          if (TypeSupport.isParentClass(StringValue.class, type1, type2))
47              this.setTypedExpr(new StringCalculation(this.getExprArg(0), this.getOperator(), this.getExprArg(1)));
48          else if (TypeSupport.isParentClass(NumberValue.class, type1, type2))
49              this.setTypedExpr(new NumberCalculation(this.getExprArg(0), this.getOperator(), this.getExprArg(1)));
50          else if (TypeSupport.isParentClass(DateValue.class, type1, type2))
51              this.setTypedExpr(new DateCalculation(this.getExprArg(0), this.getOperator(), this.getExprArg(1)));
52          else
53              this.throwInvalidTypeException(type1, type2);
54  
55          return this.getTypedExpr().validateTypes(parentExpr, false);
56      }
57  
58      public GenericValue getOptimizedValue() throws HBqlException {
59          this.optimizeAllArgs();
60          return !this.isAConstant() ? this : this.getTypedExpr().getOptimizedValue();
61      }
62  
63      public Object getValue(final HConnectionImpl conn, final Object object) throws HBqlException,
64                                                                                     ResultMissingColumnException,
65                                                                                     NullColumnValueException {
66          return this.getTypedExpr().getValue(conn, object);
67      }
68  }