forked from OpenFeign/feign
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathUtil.java
More file actions
157 lines (144 loc) · 5.17 KB
/
Util.java
File metadata and controls
157 lines (144 loc) · 5.17 KB
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
/*
* Copyright 2013 Netflix, Inc.
*
* 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 feign;
import java.io.IOException;
import java.lang.reflect.Array;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import static java.lang.String.format;
/**
* Utilities, typically copied in from guava, so as to avoid dependency conflicts.
*/
public class Util {
private Util() { // no instances
}
/**
* The HTTP Content-Length header field name.
*/
public static final String CONTENT_LENGTH = "Content-Length";
/**
* The HTTP Retry-After header field name.
*/
public static final String RETRY_AFTER = "Retry-After";
// com.google.common.base.Charsets
/**
* UTF-8: eight-bit UCS Transformation Format.
*/
public static final Charset UTF_8 = Charset.forName("UTF-8");
/**
* Copy of {@code com.google.common.base.Preconditions#checkArgument}.
*/
public static void checkArgument(boolean expression,
String errorMessageTemplate,
Object... errorMessageArgs) {
if (!expression) {
throw new IllegalArgumentException(
format(errorMessageTemplate, errorMessageArgs));
}
}
/**
* Copy of {@code com.google.common.base.Preconditions#checkNotNull}.
*/
public static <T> T checkNotNull(T reference,
String errorMessageTemplate,
Object... errorMessageArgs) {
if (reference == null) {
// If either of these parameters is null, the right thing happens anyway
throw new NullPointerException(
format(errorMessageTemplate, errorMessageArgs));
}
return reference;
}
/**
* Copy of {@code com.google.common.base.Preconditions#checkState}.
*/
public static void checkState(boolean expression,
String errorMessageTemplate,
Object... errorMessageArgs) {
if (!expression) {
throw new IllegalStateException(
format(errorMessageTemplate, errorMessageArgs));
}
}
/**
* Adapted from {@code com.google.common.base.Strings#emptyToNull}.
*/
public static String emptyToNull(String string) {
return string == null || string.isEmpty() ? null : string;
}
/**
* Adapted from {@code com.google.common.base.Strings#emptyToNull}.
*/
@SuppressWarnings("unchecked")
public static <T> T[] toArray(Iterable<? extends T> iterable, Class<T> type) {
Collection<T> collection;
if (iterable instanceof Collection) {
collection = (Collection<T>) iterable;
} else {
collection = new ArrayList<T>();
for (T element : iterable) {
collection.add(element);
}
}
T[] array = (T[]) Array.newInstance(type, collection.size());
return collection.toArray(array);
}
/**
* Returns an unmodifiable collection which may be empty, but is never null.
*/
public static <T> Collection<T> valuesOrEmpty(Map<String, Collection<T>> map, String key) {
return map.containsKey(key) ? map.get(key) : Collections.<T>emptyList();
}
public static void ensureClosed(Response.Body body) {
if (body != null) {
try {
body.close();
} catch (IOException ignored) { // NOPMD
}
}
}
/**
* Resolves the last type parameter of the parameterized {@code supertype}, based on the {@code genericContext},
* into its upper bounds.
* <p/>
* Implementation copied from {@code retrofit.RestMethodInfo}.
*
* @param genericContext Ex. {@link java.lang.reflect.Field#getGenericType()}
* @param supertype Ex. {@code Decoder.class}
* @return in the example above, the type parameter of {@code Decoder}.
* @throws IllegalStateException if {@code supertype} cannot be resolved into a parameterized type using
* {@code context}.
*/
public static Type resolveLastTypeParameter(Type genericContext, Class<?> supertype) throws IllegalStateException {
Type resolvedSuperType = Types.getSupertype(genericContext, Types.getRawType(genericContext), supertype);
checkState(resolvedSuperType instanceof ParameterizedType, "could not resolve %s into a parameterized type %s",
genericContext, supertype);
Type[] types = ParameterizedType.class.cast(resolvedSuperType).getActualTypeArguments();
for (int i = 0; i < types.length; i++) {
Type type = types[i];
if (type instanceof WildcardType) {
types[i] = ((WildcardType) type).getUpperBounds()[0];
}
}
return types[types.length - 1];
}
}