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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
/*
* Copyright 2011 Vaadin Ltd.
*
* 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.vaadin.data.util.converter;
import java.io.Serializable;
import java.util.Locale;
import com.vaadin.server.VaadinSession;
public class ConverterUtil implements Serializable {
/**
* Finds a converter that can convert from the given presentation type to
* the given model type and back. Uses the given application to find a
* {@link ConverterFactory} or, if application is null, uses the
* {@link VaadinSession#getCurrent()}.
*
* @param <PRESENTATIONTYPE>
* The presentation type
* @param <MODELTYPE>
* The model type
* @param presentationType
* The presentation type
* @param modelType
* The model type
* @param application
* The application to use to find a ConverterFactory or null to
* use the current application
* @return A Converter capable of converting between the given types or null
* if no converter was found
*/
public static <PRESENTATIONTYPE, MODELTYPE> Converter<PRESENTATIONTYPE, MODELTYPE> getConverter(
Class<PRESENTATIONTYPE> presentationType,
Class<MODELTYPE> modelType, VaadinSession application) {
Converter<PRESENTATIONTYPE, MODELTYPE> converter = null;
if (application == null) {
application = VaadinSession.getCurrent();
}
if (application != null) {
ConverterFactory factory = application.getConverterFactory();
converter = factory.createConverter(presentationType, modelType);
}
return converter;
}
/**
* Convert the given value from the data source type to the UI type.
*
* @param modelValue
* The model value to convert
* @param presentationType
* The type of the presentation value
* @param converter
* The converter to (try to) use
* @param locale
* The locale to use for conversion
* @param <PRESENTATIONTYPE>
* Presentation type
*
* @return The converted value, compatible with the presentation type, or
* the original value if its type is compatible and no converter is
* set.
* @throws Converter.ConversionException
* if there is no converter and the type is not compatible with
* the model type.
*/
@SuppressWarnings("unchecked")
public static <PRESENTATIONTYPE, MODELTYPE> PRESENTATIONTYPE convertFromModel(
MODELTYPE modelValue,
Class<? extends PRESENTATIONTYPE> presentationType,
Converter<PRESENTATIONTYPE, MODELTYPE> converter, Locale locale)
throws Converter.ConversionException {
if (converter != null) {
return converter.convertToPresentation(modelValue, locale);
}
if (modelValue == null) {
return null;
}
if (presentationType.isAssignableFrom(modelValue.getClass())) {
return (PRESENTATIONTYPE) modelValue;
} else {
throw new Converter.ConversionException(
"Unable to convert value of type "
+ modelValue.getClass().getName()
+ " to presentation type "
+ presentationType
+ ". No converter is set and the types are not compatible.");
}
}
/**
* @param <MODELTYPE>
* @param <PRESENTATIONTYPE>
* @param presentationValue
* @param modelType
* @param converter
* @param locale
* @return
* @throws Converter.ConversionException
*/
public static <MODELTYPE, PRESENTATIONTYPE> MODELTYPE convertToModel(
PRESENTATIONTYPE presentationValue, Class<MODELTYPE> modelType,
Converter<PRESENTATIONTYPE, MODELTYPE> converter, Locale locale)
throws Converter.ConversionException {
if (converter != null) {
/*
* If there is a converter, always use it. It must convert or throw
* an exception.
*/
return converter.convertToModel(presentationValue, locale);
}
if (presentationValue == null) {
// Null should always be passed through the converter but if there
// is no converter we can safely return null
return null;
}
if (modelType == null) {
// No model type, return original value
return (MODELTYPE) presentationValue;
} else if (modelType.isAssignableFrom(presentationValue.getClass())) {
// presentation type directly compatible with model type
return modelType.cast(presentationValue);
} else {
throw new Converter.ConversionException(
"Unable to convert value of type "
+ presentationValue.getClass().getName()
+ " to model type "
+ modelType
+ ". No converter is set and the types are not compatible.");
}
}
/**
* Checks if the given converter can handle conversion between the given
* presentation and model type
*
* @param converter
* The converter to check
* @param presentationType
* The presentation type
* @param modelType
* The model type
* @return true if the converter supports conversion between the given
* presentation and model type, false otherwise
*/
public static boolean canConverterHandle(Converter<?, ?> converter,
Class<?> presentationType, Class<?> modelType) {
if (converter == null) {
return false;
}
if (!modelType.isAssignableFrom(converter.getModelType())) {
return false;
}
if (!presentationType.isAssignableFrom(converter.getPresentationType())) {
return false;
}
return true;
}
}
|
