jdk-24/test/jdk/java/net/httpclient/examples/JavadocExamples.java
Patrick Concannon 9fe2d31d6e 8252304: Seed an HttpRequest.Builder from an existing HttpRequest
Co-authored-by: Chris Hegarty <chegar@openjdk.org>
Reviewed-by: chegar, dfuchs, michaelm
2020-11-19 09:35:49 +00:00

362 lines
14 KiB
Java

/*
* Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.io.UncheckedIOException;
import java.lang.reflect.UndeclaredThrowableException;
import java.net.Authenticator;
import java.net.InetSocketAddress;
import java.net.ProxySelector;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpClient.Redirect;
import java.net.http.HttpClient.Version;
import java.net.http.HttpRequest;
import java.net.http.HttpRequest.BodyPublishers;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandler;
import java.net.http.HttpResponse.BodyHandlers;
import java.net.http.HttpResponse.BodySubscriber;
import java.net.http.HttpResponse.BodySubscribers;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.Flow;
import java.util.function.Supplier;
import java.util.regex.Pattern;
import static java.nio.charset.StandardCharsets.UTF_8;
/*
* THE CONTENTS OF THIS FILE HAVE TO BE IN SYNC WITH THE EXAMPLES USED IN THE
* JAVADOC.
*
* @test
* @compile JavadocExamples.java
*/
public class JavadocExamples {
HttpRequest request = null;
HttpClient client = null;
Pattern p = null;
void fromHttpClientClasslevelDescription() throws Exception {
//Synchronous Example
HttpClient client = HttpClient.newBuilder()
.version(Version.HTTP_1_1)
.followRedirects(Redirect.NORMAL)
.connectTimeout(Duration.ofSeconds(20))
.proxy(ProxySelector.of(new InetSocketAddress("proxy.example.com", 80)))
.authenticator(Authenticator.getDefault())
.build();
HttpResponse<String> response = client.send(request, BodyHandlers.ofString());
System.out.println(response.statusCode());
System.out.println(response.body());
//Asynchronous Example
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("https://foo.com/"))
.timeout(Duration.ofMinutes(2))
.header("Content-Type", "application/json")
.POST(BodyPublishers.ofFile(Paths.get("file.json")))
.build();
client.sendAsync(request, BodyHandlers.ofString())
.thenApply(HttpResponse::body)
.thenAccept(System.out::println);
}
void fromHttpRequest() throws Exception {
// HttpRequest class-level description
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("http://foo.com/"))
.build();
client.sendAsync(request, BodyHandlers.ofString())
.thenApply(HttpResponse::body)
.thenAccept(System.out::println)
.join();
// HttpRequest.BodyPublishers class-level description
// Request body from a String
HttpRequest request1 = HttpRequest.newBuilder()
.uri(URI.create("https://foo.com/"))
.header("Content-Type", "text/plain; charset=UTF-8")
.POST(BodyPublishers.ofString("some body text"))
.build();
// Request body from a File
HttpRequest request2 = HttpRequest.newBuilder()
.uri(URI.create("https://foo.com/"))
.header("Content-Type", "application/json")
.POST(BodyPublishers.ofFile(Paths.get("file.json")))
.build();
// Request body from a byte array
HttpRequest request3 = HttpRequest.newBuilder()
.uri(URI.create("https://foo.com/"))
.POST(BodyPublishers.ofByteArray(new byte[] { /*...*/ }))
.build();
// HttpRequest.Builder
// API note - newBuilder(HttpRequest, BiPredicate<String, String>)
// Retain all headers:
HttpRequest.newBuilder(request, (n, v) -> true);
//Remove all headers:
HttpRequest.newBuilder(request, (n, v) -> false);
// Remove a particular header (e.g. Foo-Bar):
HttpRequest.newBuilder(request, (name, value) ->
!name.equalsIgnoreCase("Foo-Bar"));
}
void fromHttpResponse() throws Exception {
// HttpResponse class-level description
HttpResponse<String> response = client
.send(request, BodyHandlers.ofString());
// HttpResponse.BodyHandler class-level description
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("http://www.foo.com/"))
.build();
client.sendAsync(request, BodyHandlers.ofFile(Paths.get("/tmp/f")))
.thenApply(HttpResponse::body)
.thenAccept(System.out::println);
HttpRequest request1 = HttpRequest.newBuilder()
.uri(URI.create("http://www.foo.com/"))
.build();
BodyHandler<Path> bodyHandler = (info) -> info.statusCode() == 200
? BodySubscribers.ofFile(Paths.get("/tmp/f"))
: BodySubscribers.replacing(Paths.get("/NULL"));
client.sendAsync(request, bodyHandler)
.thenApply(HttpResponse::body)
.thenAccept(System.out::println);
// HttpResponse.BodyHandlers class-level description
// Receives the response body as a String
HttpResponse<String> response1 = client
.send(request, BodyHandlers.ofString());
// Receives the response body as a file
HttpResponse<Path> response2 = client
.send(request, BodyHandlers.ofFile(Paths.get("example.html")));
// Receives the response body as an InputStream
HttpResponse<InputStream> respons3 = client
.send(request, BodyHandlers.ofInputStream());
// Discards the response body
HttpResponse<Void> respons4 = client
.send(request, BodyHandlers.discarding());
// HttpResponse.BodySubscribers class-level description
// Streams the response body to a File
HttpResponse<Path> response5 = client
.send(request, responseInfo -> BodySubscribers.ofFile(Paths.get("example.html")));
// Accumulates the response body and returns it as a byte[]
HttpResponse<byte[]> response6 = client
.send(request, responseInfo -> BodySubscribers.ofByteArray());
// Discards the response body
HttpResponse<Void> response7 = client
.send(request, responseInfo -> BodySubscribers.discarding());
// Accumulates the response body as a String then maps it to its bytes
HttpResponse<byte[]> response8 = client
.send(request, responseInfo ->
BodySubscribers.mapping(BodySubscribers.ofString(UTF_8), String::getBytes));
// Maps an InputStream to a Foo object.
HttpResponse<Supplier<Foo>> response9 = client.send(request,
(resp) -> FromMappingSubscriber.asJSON(Foo.class));
String resp = response9.body().get().asString();
}
/**
* @apiNote This method can be used as an adapter between a {@code
* BodySubscriber} and a text based {@code Flow.Subscriber} that parses
* text line by line.
*
* <p> For example:
* <pre> {@code // A PrintSubscriber that implements Flow.Subscriber<String>
* // and print lines received by onNext() on System.out
* PrintSubscriber subscriber = new PrintSubscriber(System.out);
* client.sendAsync(request, BodyHandlers.fromLineSubscriber(subscriber))
* .thenApply(HttpResponse::statusCode)
* .thenAccept((status) -> {
* if (status != 200) {
* System.err.printf("ERROR: %d status received%n", status);
* }
* }); }</pre>
*/
void fromLineSubscriber1() {
// A PrintSubscriber that implements Flow.Subscriber<String>
// and print lines received by onNext() on System.out
PrintSubscriber subscriber = new PrintSubscriber(System.out);
client.sendAsync(request, BodyHandlers.fromLineSubscriber(subscriber))
.thenApply(HttpResponse::statusCode)
.thenAccept((status) -> {
if (status != 200) {
System.err.printf("ERROR: %d status received%n", status);
}
});
}
/**
* @apiNote This method can be used as an adapter between a {@code
* BodySubscriber} and a text based {@code Flow.Subscriber} that parses
* text line by line.
*
* <p> For example:
* <pre> {@code // A LineParserSubscriber that implements Flow.Subscriber<String>
* // and accumulates lines that match a particular pattern
* Pattern pattern = ...;
* LineParserSubscriber subscriber = new LineParserSubscriber(pattern);
* HttpResponse<List<String>> response = client.send(request,
* BodyHandlers.fromLineSubscriber(subscriber, s -> s.getMatchingLines(), "\n"));
* if (response.statusCode() != 200) {
* System.err.printf("ERROR: %d status received%n", response.statusCode());
* } }</pre>
*
*/
void fromLineSubscriber2() throws IOException, InterruptedException {
// A LineParserSubscriber that implements Flow.Subscriber<String>
// and accumulates lines that match a particular pattern
Pattern pattern = p;
LineParserSubscriber subscriber = new LineParserSubscriber(pattern);
HttpResponse<List<String>> response = client.send(request,
BodyHandlers.fromLineSubscriber(subscriber, s -> s.getMatchingLines(), "\n"));
if (response.statusCode() != 200) {
System.err.printf("ERROR: %d status received%n", response.statusCode());
}
}
static final class PrintSubscriber implements Flow.Subscriber<String> {
final PrintStream out;
PrintSubscriber(PrintStream out) {
this.out = out;
}
@Override
public void onSubscribe(Flow.Subscription subscription) {
subscription.request(Long.MAX_VALUE);
}
@Override
public void onNext(String item) {
out.println(item);
}
@Override
public void onError(Throwable throwable) {
throwable.printStackTrace();
}
@Override
public void onComplete() {
}
}
static final class LineParserSubscriber implements Flow.Subscriber<String> {
final Pattern pattern;
final CopyOnWriteArrayList<String> matches = new CopyOnWriteArrayList<>();
LineParserSubscriber(Pattern pattern) {
this.pattern = pattern;
}
@Override
public void onSubscribe(Flow.Subscription subscription) {
subscription.request(Long.MAX_VALUE);
}
@Override
public void onNext(String item) {
if (pattern.matcher(item).matches()) {
matches.add(item);
}
}
@Override
public void onError(Throwable throwable) {
throwable.printStackTrace();
}
@Override
public void onComplete() {
}
public List<String> getMatchingLines() {
return Collections.unmodifiableList(matches);
}
}
public static class Foo {
byte[] bytes;
public Foo(byte[] bytes) {
this.bytes = bytes;
}
public String asString() {
return new String(bytes, UTF_8);
}
}
static class ObjectMapper {
<W> W readValue(InputStream is, Class<W> targetType)
throws IOException
{
byte[] bytes = is.readAllBytes();
return map(bytes, targetType);
}
static <W> W map(byte[] bytes, Class<W> targetType) {
try {
return targetType.getConstructor(byte[].class).newInstance(bytes);
} catch (RuntimeException | Error x) {
throw x;
} catch (Exception x) {
throw new UndeclaredThrowableException(x);
}
}
}
static class FromMappingSubscriber {
public static <W> BodySubscriber<Supplier<W>> asJSON(Class<W> targetType) {
BodySubscriber<InputStream> upstream = BodySubscribers.ofInputStream();
BodySubscriber<Supplier<W>> downstream = BodySubscribers.mapping(
upstream, (InputStream is) -> () -> {
try (InputStream stream = is) {
ObjectMapper objectMapper = new ObjectMapper();
return objectMapper.readValue(stream, targetType);
} catch (IOException e) {
throw new UncheckedIOException(e);
}
});
return downstream;
}
}
}