1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/*
* Copyright 2006 Amazon Technologies, Inc. or its affiliates.
* Amazon, Amazon.com and Carbonado are trademarks or registered trademarks
* of Amazon Technologies, Inc. or its affiliates. All rights reserved.
*
* Licensed 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 com.amazon.carbonado.qe;
import java.io.IOException;
import java.lang.reflect.UndeclaredThrowableException;
import com.amazon.carbonado.Cursor;
import com.amazon.carbonado.FetchException;
import com.amazon.carbonado.FetchMultipleException;
import com.amazon.carbonado.FetchNoneException;
import com.amazon.carbonado.PersistException;
import com.amazon.carbonado.PersistNoneException;
import com.amazon.carbonado.Query;
import com.amazon.carbonado.Storable;
import com.amazon.carbonado.filter.Filter;
import com.amazon.carbonado.util.Appender;
/**
* AbstractQuery implements a small set of common Query methods. Subclasses
* should consider overriding some of these methods, if it provides better
* performance.
*
* @author Brian S O'Neill
*/
public abstract class AbstractQuery<S extends Storable> implements Query<S>, Appender {
protected AbstractQuery() {
}
public Query<S> and(String filter) throws FetchException {
return and(Filter.filterFor(getStorableType(), filter));
}
public Query<S> or(String filter) throws FetchException {
return or(Filter.filterFor(getStorableType(), filter));
}
public Cursor<S> fetchAfter(S start) throws FetchException {
return after(start).fetch();
}
public S loadOne() throws FetchException {
S obj = tryLoadOne();
if (obj == null) {
throw new FetchNoneException(toString());
}
return obj;
}
public S tryLoadOne() throws FetchException {
Cursor<S> cursor = fetch();
try {
if (cursor.hasNext()) {
S obj = cursor.next();
if (cursor.hasNext()) {
throw new FetchMultipleException(toString());
}
return obj;
} else {
return null;
}
} finally {
cursor.close();
}
}
public void deleteOne() throws PersistException {
if (!tryDeleteOne()) {
throw new PersistNoneException(toString());
}
}
public boolean printNative() {
try {
return printNative(System.out);
} catch (IOException e) {
// Shouldn't happen since PrintStream suppresses exceptions.
throw new UndeclaredThrowableException(e);
}
}
public boolean printNative(Appendable app) throws IOException {
return printNative(app, 0);
}
public boolean printPlan() {
try {
return printPlan(System.out);
} catch (IOException e) {
// Shouldn't happen since PrintStream suppresses exceptions.
throw new UndeclaredThrowableException(e);
}
}
public boolean printPlan(Appendable app) throws IOException {
return printPlan(app, 0);
}
/**
* Implementation calls appendTo.
*/
@Override
public String toString() {
StringBuilder b = new StringBuilder();
try {
appendTo(b);
} catch (IOException e) {
// Not gonna happen
}
return b.toString();
}
@Override
public abstract int hashCode();
@Override
public abstract boolean equals(Object obj);
/**
* Called by sliced fetch to ensure that arguments are valid.
*
* @return false if from is 0 and to is null
* @throws IllegalArgumentException if arguments are invalid
* @since 1.2
*/
protected boolean checkSliceArguments(long from, Long to) {
if (from < 0) {
throw new IllegalArgumentException("Slice from is negative: " + from);
}
if (to == null) {
if (from == 0) {
return false;
}
} else if (from > to) {
throw new IllegalArgumentException
("Slice from is more than to: " + from + " > " + to);
}
return true;
}
}
|
