forked from OpenFeign/feign
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathAsyncFeign.java
More file actions
349 lines (284 loc) · 10 KB
/
AsyncFeign.java
File metadata and controls
349 lines (284 loc) · 10 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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
/**
* Copyright 2012-2021 The Feign Authors
*
* 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.Type;
import java.util.Optional;
import java.util.concurrent.*;
import java.util.function.Supplier;
import feign.Logger.NoOpLogger;
import feign.Request.Options;
import feign.Target.HardCodedTarget;
import feign.codec.Decoder;
import feign.codec.Encoder;
import feign.codec.ErrorDecoder;
/**
* Enhances {@link Feign} to provide support for asynchronous clients. Context (for example for
* session cookies or tokens) is explicit, as calls for the same session may be done across several
* threads. <br>
* <br>
* {@link Retryer} is not supported in this model, as that is a blocking API.
* {@link ExceptionPropagationPolicy} is made redundant as {@link RetryableException} is never
* thrown. <br>
* Alternative approaches to retrying can be handled through {@link AsyncClient clients}. <br>
* <br>
* Target interface methods must return {@link CompletableFuture} with a non-wildcard type. As the
* completion is done by the {@link AsyncClient}, it is important that any subsequent processing on
* the thread be short - generally, this should involve notifying some other thread of the work to
* be done (for example, creating and submitting a task to an {@link ExecutorService}).
*
*/
@Experimental
public abstract class AsyncFeign<C> extends Feign {
public static <C> AsyncBuilder<C> asyncBuilder() {
return new AsyncBuilder<>();
}
private static class LazyInitializedExecutorService {
private static final ExecutorService instance = Executors.newCachedThreadPool(r -> {
final Thread result = new Thread(r);
result.setDaemon(true);
return result;
});
}
public static class AsyncBuilder<C> {
private final Builder builder;
private Supplier<C> defaultContextSupplier = () -> null;
private AsyncClient<C> client;
private Logger.Level logLevel = Logger.Level.NONE;
private final Logger logger = new NoOpLogger();
private Decoder decoder = new Decoder.Default();
private ErrorDecoder errorDecoder = new ErrorDecoder.Default();
private boolean decode404;
private boolean closeAfterDecode = true;
public AsyncBuilder() {
super();
this.builder = Feign.builder();
}
public AsyncBuilder<C> defaultContextSupplier(Supplier<C> supplier) {
this.defaultContextSupplier = supplier;
return this;
}
public AsyncBuilder<C> client(AsyncClient<C> client) {
this.client = client;
return this;
}
/**
* @see Builder#mapAndDecode(ResponseMapper, Decoder)
*/
public AsyncBuilder<C> mapAndDecode(ResponseMapper mapper, Decoder decoder) {
this.decoder = (response, type) -> decoder.decode(mapper.map(response, type), type);
return this;
}
/**
* @see Builder#decoder(Decoder)
*/
public AsyncBuilder<C> decoder(Decoder decoder) {
this.decoder = decoder;
return this;
}
/**
* @see Builder#decode404()
*/
public AsyncBuilder<C> decode404() {
this.decode404 = true;
return this;
}
/**
* @see Builder#errorDecoder(ErrorDecoder)
*/
public AsyncBuilder<C> errorDecoder(ErrorDecoder errorDecoder) {
this.errorDecoder = errorDecoder;
return this;
}
public AsyncBuilder<C> doNotCloseAfterDecode() {
this.closeAfterDecode = false;
return this;
}
public <T> T target(Class<T> apiType, String url) {
return target(new HardCodedTarget<>(apiType, url));
}
public <T> T target(Class<T> apiType, String url, C context) {
return target(new HardCodedTarget<>(apiType, url), context);
}
public <T> T target(Target<T> target) {
return build().newInstance(target);
}
public <T> T target(Target<T> target, C context) {
return build().newInstance(target, context);
}
private AsyncBuilder<C> lazyInits() {
if (client == null) {
client = new AsyncClient.Default<>(new Client.Default(null, null),
LazyInitializedExecutorService.instance);
}
return this;
}
public AsyncFeign<C> build() {
return new ReflectiveAsyncFeign<>(lazyInits());
}
// start of builder delgates
/**
* @see Builder#logLevel(Logger.Level)
*/
public AsyncBuilder<C> logLevel(Logger.Level logLevel) {
builder.logLevel(logLevel);
this.logLevel = logLevel;
return this;
}
/**
* @see Builder#contract(Contract)
*/
public AsyncBuilder<C> contract(Contract contract) {
builder.contract(contract);
return this;
}
/**
* @see Builder#logLevel(Logger.Level)
*/
public AsyncBuilder<C> logger(Logger logger) {
builder.logger(logger);
return this;
}
/**
* @see Builder#encoder(Encoder)
*/
public AsyncBuilder<C> encoder(Encoder encoder) {
builder.encoder(encoder);
return this;
}
/**
* @see Builder#queryMapEncoder(QueryMapEncoder)
*/
public AsyncBuilder<C> queryMapEncoder(QueryMapEncoder queryMapEncoder) {
builder.queryMapEncoder(queryMapEncoder);
return this;
}
/**
* @see Builder#options(Options)
*/
public AsyncBuilder<C> options(Options options) {
builder.options(options);
return this;
}
/**
* @see Builder#requestInterceptor(RequestInterceptor)
*/
public AsyncBuilder<C> requestInterceptor(RequestInterceptor requestInterceptor) {
builder.requestInterceptor(requestInterceptor);
return this;
}
/**
* @see Builder#requestInterceptors(Iterable)
*/
public AsyncBuilder<C> requestInterceptors(Iterable<RequestInterceptor> requestInterceptors) {
builder.requestInterceptors(requestInterceptors);
return this;
}
/**
* @see Builder#invocationHandlerFactory(InvocationHandlerFactory)
*/
public AsyncBuilder<C> invocationHandlerFactory(InvocationHandlerFactory invocationHandlerFactory) {
builder.invocationHandlerFactory(invocationHandlerFactory);
return this;
}
}
private final ThreadLocal<AsyncInvocation<C>> activeContext;
private final Feign feign;
private final Supplier<C> defaultContextSupplier;
private final AsyncClient<C> client;
private final Logger.Level logLevel;
private final Logger logger;
private final AsyncResponseHandler responseHandler;
protected AsyncFeign(AsyncBuilder<C> asyncBuilder) {
this.activeContext = new ThreadLocal<>();
this.defaultContextSupplier = asyncBuilder.defaultContextSupplier;
this.client = asyncBuilder.client;
this.logLevel = asyncBuilder.logLevel;
this.logger = asyncBuilder.logger;
this.responseHandler = new AsyncResponseHandler(
asyncBuilder.logLevel,
asyncBuilder.logger,
asyncBuilder.decoder,
asyncBuilder.errorDecoder,
asyncBuilder.decode404,
asyncBuilder.closeAfterDecode);
asyncBuilder.builder.client(this::stageExecution);
asyncBuilder.builder.decoder(this::stageDecode);
asyncBuilder.builder.forceDecoding(); // force all handling through stageDecode
this.feign = asyncBuilder.builder.build();
}
private Response stageExecution(Request request, Options options) {
final Response result = Response.builder()
.status(200)
.request(request)
.build();
final AsyncInvocation<C> invocationContext = activeContext.get();
invocationContext.setResponseFuture(
client.execute(request, options, Optional.ofNullable(invocationContext.context())));
return result;
}
// from SynchronousMethodHandler
long elapsedTime(long start) {
return TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start);
}
private Object stageDecode(Response response, Type type) {
final AsyncInvocation<C> invocationContext = activeContext.get();
final CompletableFuture<Object> result = new CompletableFuture<>();
invocationContext.responseFuture().whenComplete((r, t) -> {
final long elapsedTime = elapsedTime(invocationContext.startNanos());
if (t != null) {
if (logLevel != Logger.Level.NONE && t instanceof IOException) {
final IOException e = (IOException) t;
logger.logIOException(invocationContext.configKey(), logLevel, e, elapsedTime);
}
result.completeExceptionally(t);
} else {
responseHandler.handleResponse(result, invocationContext.configKey(), r,
invocationContext.underlyingType(), elapsedTime);
}
});
result.whenComplete((r, t) -> {
if (result.isCancelled()) {
invocationContext.responseFuture().cancel(true);
}
});
if (invocationContext.isAsyncReturnType()) {
return result;
}
try {
return result.join();
} catch (final CompletionException e) {
final Response r = invocationContext.responseFuture().join();
Throwable cause = e.getCause();
if (cause == null) {
cause = e;
}
throw new AsyncJoinException(r.status(), cause.getMessage(), r.request(), cause);
}
}
protected void setInvocationContext(AsyncInvocation<C> invocationContext) {
activeContext.set(invocationContext);
}
protected void clearInvocationContext() {
activeContext.remove();
}
@Override
public <T> T newInstance(Target<T> target) {
return newInstance(target, defaultContextSupplier.get());
}
public <T> T newInstance(Target<T> target, C context) {
return wrap(target.type(), feign.newInstance(target), context);
}
protected abstract <T> T wrap(Class<T> type, T instance, C context);
}